注射模类外文文献翻译

第一篇译文（中文）

2.3注射模

2.3.1注射模塑

注塑主要用于热塑性制件的生产，它也是最古老的塑料成型方式之一。目前，注塑占所有塑料树脂消费的30%。典型的注塑产品主要有杯子器具、容器、机架、工具手柄、旋钮（球形捏手）、电器和通讯部件（如电话接收器），玩具和铅管制造装置。

聚合物熔体因其较高的分子质量而具有很高的粘性；它们不能像金属一样在重力流的作用下直接被倒入模具中，而是需要在高压的作用下强行注入模具中。因此当一个金属铸件的机械性能主要由模壁热传递的速率决定，这决定了最终铸件的晶粒度和纤维取向，也决定了注塑时熔体注入时的高压产生强大的剪切力是物料中分子取向的主要决定力量。由此所知，成品的机械性能主要受注射条件和在模具中的冷却条件影响。

注塑已经被应用于热塑性塑料和热固性塑料、泡沫部分，而且也已经被改良用于生产反应注塑过程，在此过程中，一个热固树脂系统的两个组成部分在模具中同时被注射填充，然后迅速聚合。然而大多数注塑被用热塑性塑料上，接下来的讨论就集中在这样的模具上。

典型的注塑周期或流程包括五个阶段（见图2-1）：

（1）注射或模具填充；

（2）填充或压紧；

（3）定型；

（4）冷却；

（5）零件顶出。

图2-1 注塑流程

塑料芯块（或粉末）被装入进料斗，穿过一条在注射料筒中通过旋转螺杆的作用下塑料芯块（或粉末）被向前推进的通道。螺杆的旋转迫使这些芯块在高压下对抗使它们受热融化的料筒加热壁。加热温度在265至500华氏度之间。随着压力增强，旋转螺杆被推向后压直到积累了足够的塑料能够发射。注射活塞迫使熔融塑料从料筒，通过喷嘴、浇口和流道系统，最后进入模具型腔。在注塑过程中，模具型腔被完全充满。当塑料接触冰冷的模具表面，便迅速固化形成表层。由于型芯还处于熔融状态，塑料流经型芯来完成模具的填充。典型地，在注塑过程中模具型腔被填充至95%~98%。

然后模具成型过程将进行至压紧阶段。当模具型腔充满的时候，熔融的塑料便开始冷却。由于塑料冷却过程中会收缩，这增加了收缩痕、气空、尺寸不稳定性等瑕疵。为了弥补收缩，额外的塑料就要被压入型腔。型腔一旦被填充，作用于使物料熔化的压力就会阻止模具型腔中的熔融塑料由模具型腔浇口处回流。压力一直作用到模具型腔浇口固化。这个过程可以分为两步（压紧和定型），或者一步完成（定型或者第二阶段）。在压紧过程中，熔化物通过补偿收缩的保压压力来进入型腔。固化成型过程中，压力仅仅是为了阻止聚合物熔化物逆流。

固化成型阶段完成之后，冷却阶段便开始了。在这个阶段中，部件在模具中停留某一规定时间。冷却阶段的时间长短主要取决于材料特性和部件的厚度。典型地，部件的温度必须冷却到物料的喷出温度以下。

冷却部件时，机器将熔化物塑炼以供下一个周期使用。高聚物受剪切作用和电热丝的能量情况影响。一旦喷射成功，塑炼过程便停止了。这是在冷却阶段结束之前瞬间发生的。然后模具打开，部件便生产出来了。

2.3.2注塑模具

注塑模具与它们的生产出来的产品一样，在设计、精密度和尺寸方面各不相同。热塑性模具的功能主要是把可塑性聚合物制成人们想要的形状，然后再将模制部件冷却。

模具主要由两个部件组成：（1）型腔和型芯，（2）固定型腔和型芯的底座。模制品的尺寸和重量限制了模具型腔的数量，同时也决定了所需设备的能力。从模具成型过程考虑，模具设计时要能安全合模、注射、脱模的作用力。此外，浇口和流道的设计必须允许有效的流动以及模具型腔均匀填充。

图2-2举例说明了典型注射模具中的部件。模具主要由两部分组成：固定部分（型腔固定板），熔化的聚合物被注入的旁边；在注塑设备结尾或排出旁边的瓣合（中心板）部分。模具这两部分之间的分隔线叫做分型线。注射材料通过一条叫做浇口的中心进料通道被转运。浇口位于浇口轴套的上面，它逐渐缩小（锥形）是为了促进模具打开时浇注材料的释放。在多型腔模具中，主流道将高分子聚合熔化物提供到流道系统中，流道系统通过浇口流入每个模具型腔。

中心板支撑主型芯。主型芯的用途是确立部件的内部结构。中心板有一个支持或支撑板。支撑板反过来被背对注塑模顶杆空间的U型结构的柱子支撑，注塑模顶杆空间由背面的压板和垫块组成。被固定在中心板上的U型结构，为也被叫做脱模行程的顶出行程提供了空间。在固化的过程中，部件从主型芯周围收缩以至于当模具打开的时候，部件和浇口随着瓣合机构一起被带出来。接着，中央的起模杆被激活，引起脱模板向前移动以至于顶杆能够推动部件离开型芯。带有冷却通道的上下模被提供，冷却通道通过冷却水循环流通来吸收热塑性高分子聚合熔融物传递给模具的热量。模具型腔也包含好的通风口（对于5毫米而言，通风口应该为0.02到0.08毫米）来确保填充过程中没有空气滞留在模具型腔内。

1-顶杆2-顶出板3-导套4-导柱5-下顶针板6-脱件销7-复位杆8-限位杆

9-导柱10-导柱11-型腔板12-浇口套13-塑料工件14-型芯

现在使用的有六种基本注射模具类型。它们是：（1）双板模；（2）三板模；（3）热流道模具；（4）绝热保温流道模具；（5）温流道模具；和（6）重叠压塑模具。图2-3和图2-4阐明了这六种基本注射模具类型。

1.双板模

一个双板模具由每块都带有型腔和型芯的两块平板组成。平板被固定在压板上。瓣合机构包含工件自动拆卸机构和流道系统。所有注射模具的基本设计都有这个思想。双板模具是用来制作要求大型浇口制品的最合理的工具。

2.三板模

这种类型的模具由三块板组成：（1）固定板或压板被连接到固定压盘上，通常包含主流道和分流道；（2）当模具打开的时候，包含分流道和浇口中间板或型腔固定板是被允许浮动的；（3）活动板或阳模板包含模制件和用来除去模制件的顶出装置。当按压进行打开的时候，中间板和活动板一起移动，因此释放了主流道和分流道系统和清除了浇口处模制品的赘物。当模具打开的时候，这种设计类型的模具使分离流道系统和模制件变成了可能。这种模具设计让点浇口浇注系统能够运用。

3.热流道模具

在这个注射模具的流程中，分流道要保持热的，目的是使熔融的塑料一直处于流动的状态。实际上，这是一个“无流道”模具流程，有时候它也被叫做无流道模具。在无流道模具中，分流道被包含在自己的板中。热流道模具除了模塑周期中模具的分流道部分不被打开这点外，其他地方与三板注射模具相似。加热流道板与剩下的冷却部分的模具是绝缘的。分流道中除了热加板，模具中剩余部分是一个标准的两板模具。

无流道模具相比传统的浇口流道模具有几个优点。无流道模具没有模具副产品（浇口，分流道，主流道）被处理或者再利用，也没有浇口与制件的分离。周期仅仅要求制件被冷却和从模具中脱离。在这个系统中，从注射料筒到模具型腔，温度能够达到统一。

4.绝热保温流道模具

绝热流道模具是热流道模具的一种演变。在这种类型的模具中，分流道材料的外表面充当了绝缘体来让熔融材料通过。在隔热的模具中，通过保留自己的温度使模具中的物料一直是熔化的。有时候，一个分料梭和热探测器被加入模具中来增加柔韧性。这种类型的模具对于多孔中心浇口的制件来说是理想的。

5.温流道模具

它是热流道模具的一种演变。在这种模具中，流道而不是流道板被加热。这是通过电子芯片嵌入探测器实现的。

6.重叠压塑模具

重叠压塑注射模具顾名思义。一个多重两板模具其中的一块板被放在另一块板的上面。这种结构也可以用在三板模具和热流道模具上。两板重叠结构使单一的挤压输出量加倍，与一个型腔数量相同的两板模具相比，还减少了一半的合模压力。这种方式也被叫做“双层模塑”。

2.3.3压膜机

1.传统的注塑机

在这个流程中，塑料颗粒或粉末被倒入一个机器料斗中，然后被送入加热料筒室。一个活塞压缩物料，迫使物料渐进地通过加热料筒中物料被分料梭慢慢散开的加热区域。分料梭被安装在料筒的中心，目的是加速塑料体中心的加热。分料梭也有可能被加热，以便塑料能够内外一起被加热。

物料从加热料斗流经喷嘴进入模具。喷嘴是料斗和模具之间的密封装置它被用来阻止因为剩余压力而引起的物料泄露。模具在注塑机的末端被夹具夹紧闭合。对于聚苯乙烯而言，机器末端两三吨的压力通常用在之间和流道系统中每个小的投影面积上。传统的活塞式机器是唯一能生产斑点部分的类型的机器。另一种类型的注塑机将塑料材料充分地混合，以至于仅有一种颜色被生产出来。

2.柱塞式预塑机

这种机器使用了分料梭活塞加热器来预塑塑料颗粒。塑料颗粒变成熔化状态之后，液态的塑料被倒入一个蓄料室，直到塑料准备好被压入模具。这种类型的机器比传统的机器生产零件的速度更快，因为在制件冷却的时间中，模具腔被填满进行喷射。由于注射活塞在流动的物料中工作，因此在压缩颗粒的时候没有压力损失。这种现象能够应用在带有更多投影面积的大型制件上。柱塞式预塑机的其他特点与传统的单一活塞式注塑机是一样的。图2-5

举例说明了柱塞式预塑机。

3.螺杆式预塑机

在这种注塑机中，用挤压机来塑化塑料物料。旋转的螺杆使塑料芯块向前，提供给挤压机料筒的加热内壁。熔融的，塑化的物料从挤压机移动到一个蓄料室，然后通过注射活塞移动到模具中。螺杆的应用有以下优势：（1）便于物料更好的混合及塑料溶化后的剪切作用；（2）流动物料硬度的范围更广及热敏材料可以流动；（3）能在更短的时间内进行色泽改变；（4）模具制件中的应力更小

4.往复式螺杆注塑机

这种类型的注塑机使用了一个水平的挤压机来代替加热室。螺杆的旋转使塑料物料向前移动通过挤压机料筒。随着物料流经带螺杆的加热料筒，物料从颗粒状态变为塑料熔融状态。螺杆往复的过程中，传递给模制物料的热量是由螺杆和挤压机的料筒壁之间的摩擦和传导引起的。当物料向前移动的时候，螺杆返回到在挤压机料筒前方决定物料容量的行程开关处。在这个时候，与典型挤压机类似的挤压过程结束了。当物料注射到模具中，螺杆向前移动来转移料筒中的物料。在这个注塑机中，螺杆既充当活塞，又充当螺杆。模具中的浇口截面冻结阻止回流之后，螺杆开始旋转并且向后移动，进行下一个周期。图2-5展示了往复式螺杆注塑机。

这种形式的注塑有几个优点。它更有效地塑化热敏感材料，由于螺杆的混合作用更快地混合色泽。给材料加热的文都能够更低，并且整个周期时间可以更短。

第一篇英文原文

2.3 Injection Molds

2.3.1 Injection Molding

Injection molding is principally used for the production of thermoplastic parts, and it is also one of the oldest. Currently injection-molding accounts for 30% of all plastics resin consumption. Typical injection-molded products are cups, containers, housings, tool handles, knobs, electrical and communication components (such as telephone receivers), toys, and plumbing fittings.

Polymer melts have very high viscosities due to their high molecular weights; they cannot be poured directly into a mold under gravity flow as metals can, but must be forced into the mold under high pressure. Therefore while the mechanical properties of a metal casting are predominantly determined by the rate of heat transfer from the mold walls, which determines the grain size and grain orientation in the final casting, in injection molding the high pressure during the injection of the melt produces shear forces that are the primary cause of the final molecular orientation in the material. The mechanical properties of the finished product are therefore affected by both the injection conditions and the cooling conditions within the mold.

Injection molding has been applied to thermoplastics and thermosets, foamed parts, and has been modified to yield the reaction injection molding (RIM) process, in which the two components of a thermosetting resin system are simultaneously injected and polymerize rapidly within the mold. Most injection molding is however performed on thermoplastics, and the discussion that follows concentrates on such moldings.

A typical injection molding cycle or sequence consists of five phases (see Fig. 2-1):

(1) Injection or mold filling;

(2) Packing or compression;

(3) Holding;

(4) Cooling;

(5) Part ejection.

Fig. 2-1 Injection molding process

Plastic pellets (or powder) are loaded into the feed hopper and through an opening in the injection cylinder where they are carried forward by the rotating screw. The rotation of the screw forces the pellets under high pressure against the heated walls of the cylinder causing them to melt. Heating temperatures range from 265 to 500 °F. As the pressure builds up, the rotating screw is

forced backward until enough plastic has accumulated to make the shot. The injection ram (or screw) forces molten plastic from the barrel, through the nozzle, sprue and runner system, and finally into the mold cavities. During injection, the mold cavity is filled volumetrically. When the plastic contacts the cold mold surfaces, it solidifies (freezes) rapidly to produce the skin layer. Since the core remains in the molten state, plastic flows through the core to complete mold filling. Typically, the cavity is filled to 95%~98% during injection.

Then the molding process is switched over to the packing phase. Even as the cavity is filled, the molten plastic begins to cool. Since the cooling plastic contracts or shrinks, it gives rise to defects such as sink marks, voids, and dimensional instabilities. To compensate for shrinkage, addition plastic is forced into the cavity. Once the cavity is packed, pressure applied to the melt prevents molten plastic inside the cavity from back flowing out through the gate. The pressure must be applied until the gate solidifies. The process can be divided into two steps (packing and holding) or may be encompassed in one step (holding or second stage). During packing, melt forced into the cavity by the packing pressure compensates for shrinkage. With holding, the pressure merely prevents back flow of the polymer melt.

After the holding stage is completed, the cooling phase starts. During cooling, the part is held in the mold for specified period. The duration of the cooling phase depends primarily on the material properties and the part thickness. Typically, the part temperature must cool below the material?s ejection temperature.

While cooling the part, the machine plasticates melt for the next cycle. The polymer is subjected to shearing action as well as the condition of the energy from the heater bands. Once the shot is made, plastication ceases. This should occur immediately before the end of the cooling phase. Then the mold opens and the part is ejected.

2.3.2 Injection Molds

Molds for injection molding are as varied in design, degree of complexity, and size as are the parts produced from them. The functions of a mold for thermoplastics are basically to impart the desired shape to the plasticized polymer and then to cool the molded part.

A mold is made up of two sets of components: (1) the cavities and cores, and (2) the base in which the cavities and cores are mounted. The size and weight of the molded parts limit the number of cavities in the mold and also determine the equipment capacity required. From consideration of the molding process, a mold has to be designed to safely absorb the forces of clamping, injection, and ejection. Also, the design of the gates and runners must allow for efficient flow and uniform filling of the mold cavities.

Fig.2-2 illustrates the parts in a typical injection mold. The mold basically consists of two parts: a stationary half (cavity plate), on the side where molten polymer is injected, and a moving half (core plate) on the closing or ejector side of the injection molding equipment. The separating line between the two mold halves is called the parting line. The injected material is transferred through a central feed channel, called the sprue. The sprue is located on the sprue bushing and is tapered to facilitate release of the sprue material from the mold during mold opening. In multicavity molds, the sprue feeds the polymer melt to a runner system, which leads into each mold cavity through a gate.

The core plate holds the main core. The purpose of the main core is to establish the inside configuration of the part. The core plate has a backup or support plate. The support plate in turn is supported by pillars against the U-shaped structure known as the ejector housing, which consists of

the rear clamping plate and spacer blocks. This U-shaped structure, which is bolted to the core plate, provides the space for the ejection stroke also known as the stripper stroke. During solidification the part shrinks around the main core so that when the mold opens, part and sprue are carried along with the moving mold half. Subsequently, the central ejector is activated, causing the ejector plates to move forward so that the ejector pins can push the part off the core. Both mold halves are provided with cooling channels through which cooled water is circulated to absorb the heat delivered to the mold by the hot thermoplastic polymer melt. The mold cavities also incorporate fine vents (0.02 to 0.08 mm by 5 mm) to ensure that no air is trapped during filling.

Fig. 2-2 Injection mold

1-ejector pin 2-ejector plate 3-guide bush 4-guide pillar 5-ejector base plate

6-sprue puller pin 7-push-back pin 8-limit pin 9-guide pillar 10-guide pillar 11-cavity plate

12-sprue bushing 13-plastic workpiece 14-core

There are six basic types of injection molds in use today. They are: (1) two-plate mold; (2) three-plate mold, (3) hot-runner mold; (4) insulated hot-runner mold; (5) hot-manifold mold; and (6) stacked mold. Fig. 2-3 and Fig. 2-4 illustrate these six basic types of injection molds.

Fig. 2-3 This illustrates three of the six basic types of injection molding dies

(1) Two-plate injection mold (2) Three-plate injection mold (3) Hot-runner mold See Fig. 2-4 for the

other three types.

Fig. 2-4 This illustrates three of the six basic types of injection molding dies

(1) Insulated runner injection mold (2) Hot manifold injection mold (3) Stacked injection mold See Fig. 2-3 for the other three types.

1. Two-Plate Mold

A two-plate mold consists of two plates with the cavity and cores mounted in either plate. The plates are fastened to the press platens. The moving half of the mold usually contains the ejector mechanism and the runner system. All basic designs for injection molds have this design concept. A two-plate mold is the most logical type of tool to use for parts that require large gates.

2. Three-Plate Mold

This type of mold is made up of three plates: (1) the stationary or runner plate is attached to the stationary platen, and usually contains the sprue and half of the runner; (2) the middle plate or cavity plate, which contains half of the runner and gate, is allowed to float when the mold is open; and (3) the movable plate or force plate contains the molded part and the ejector system for the removal of the molded part. When the press starts to open, the middle plate and the movable plate move together, thus releasing the sprue and runner system and degating the molded part. This type of mold design makes it possible to segregate the runner system and the part when the mold opens. The die design makes it possible to use center-pin-point gating.

3. Hot-Runner Mold

In this process of injection molding, the runners are kept hot in order to keep the molten plastic in a fluid state at all times. In effect this is a …runnerless? molding process and is sometimes called the same. In runnerless molds, the runner is contained in a plate of its own. Hot runner molds are similar to three-plate injection molds, except that the runner section of the mold is not opened during the molding cycle. The heated runner plate is insulated from the rest of the cooled mold. Other than the heated plate for the runner, the remainder of the mold is a standard two-plate die.

Runnerless molding has several advantages over conventional sprue runner-type molding. There are no molded side products (gates, runners, or sprues) to be disposed of or reused, and there is no separating of the gate from the part. The cycle time is only as long as is required for the molded part to be cooled and ejected from the mold. In this system, a uniform melt temperature can be attained from the injection cylinder to the mold cavities.

4. Insulated Hot-Runner Mold

This is a variation of the hot-runner mold. In this type of molding, the outer surface of the material in the runner acts like an insulator for the melten material to pass through. In the insulated mold, the molding material remains molten by retaining its own heat. Sometimes a torpedo and a hot probe are added for more flexibility. This type of mold is ideal for multicavity center-gated parts.

5. Hot-Manifold

This is a variation of the hot-runner mold. In the hot-manifold die, the runner and not the runner plate is heated. This is done by using an electric-cartridge-insert probe.

6. Stacked Mold

The stacked injection mold is just what the name implies. A multiple two-plate mold is placed one on top of the other. This construction can also be used with three-plate molds and hot-runner molds. A stacked two-mold construction doubles the output from a single press and reduces the clamping pressure required to one half, as compared to a mold of the same number of cavities in a two-plate mold. This method is sometimes called “two-level molding”.

2.3.3 Mold Machine

1. Conventional Injection-Molding Machine

In this process, the plastic granules or pellets are poured into a machine hopper and fed into the chamber of the heating cylinder. A plunger then compresses the material, forcing it through progressively hotter zones of the heating cylinder, where it is spread thin by a torpedo. The torpedo is installed in the center of the cylinder in order to accelerate the heating of the center of the plastic mass. The torpedo may also be heated so that the plastic is heated from the inside as well as from the outside.

The material flows from the heating cylinder through a nozzle into the mold. The nozzle is the seal between the cylinder and the mold; it is used to prevent leaking of material caused by the pressure used. The mold is held shut by the clamp end of the machine. For polystyrene, two to three tons of pressure on the clamp end of the machine is generally used for each inch of projected area of the part and runner system. The conventional plunger machine is the only type of machine that can produce a mottle-colored part. The other types of injection machines mix the plastic material so thoroughly that only one color will be produced.

2. Piston-Type Preplastifying Machine

This machine employs a torpedo ram heater to preplastify the plastic granules. After the melt stage, the fluid plastic is pushed into a holding chamber until it is ready to be forced into the die. This type of machine produces pieces faster than a conventional machine, because the molding chamber is filled to shot capacity during the cooling time of the part. Due to the fact that the injection plunger is acting on fluid material, no pressure loss is encountered in compacting the granules. This allows for larger parts with more projected area. The remaining features of a

piston-type preplastifying machine are identical to the conventional single-plunger injection machine. Fig. 2-5 illustrates a piston or plunger preplastifying injection molding machine.

Fig. 2-5 The four basic types of injection molding equipment

3. Screw-Type Preplastifying Machine

In this injection-molding machine, an extruder is used to plasticize the plastic material. The turning screw feeds the pellets forward to the heated interior surface of the extruder barrel. The molten, plasticized material moves from the extruder into a holding chamber, and from there is forced into the die by the injection plunger. The use of a screw gives the following advantages: (1) better mixing and shear action of the plastic melt; (2) a broader range of stiffer flow and heatsensitive materials can be run; (3) color changes can be handled in a shorter time, and (4) fewer stresses are obtained in the molded part.

4. Reciprocating-Screw Injection Machine

This type of injection molding machine employs a horizontal extruder in place of the heating chamber. The plastic material is moved forward through the extruder barrel by the rotation of a screw. As the material progresses through the heated barrel with the screw, it is changing from the granular condition to the plastic molten state. In the reciprocating screw, the heat delivered to the molding compound is caused by both friction and conduction between the screw and the walls of the barrel of the extruder. As the material moves forward, the screw backs up to a limit switch that determines the volume of material in the front of the extruder barrel. It is at this point that the re- semblance to a typical extruder ends. On the injection of the material into the die, the screw moves forward to displace the material in the barrel. In this machine, the screw performs as a ram as well as a screw. After the gate sections in the mold have frozen to prevent backflow, the screw begins to rotate and moves backward for the next cycle. Fig.2-5 shows a reciprocating-screw injection machine.

There are several advantages to this method of injection molding. It more efficiently plasticizes the heat-sensitive materials and blends colors more rapidly, due to the mixing action of the screw. The material heat is usually lower and the overall cycle time is shorter.

第二篇译文

环保意识的设计和制造

ECD＆M研究的问题包括：产品与过程集成与材料选择系统的设计，评估消费者的需

求和产品使用的集成模型的发展，处理或回收，改进的方法，工具和对环境危害和成本或效益的风险评估程序，在加工或最终产品的材料，降低对环境的影响替代，在预测特定的政府法规的影响在整个产品生命周期技术的进步，新的或改进的制造过程，和增加的寿命，可以减少环境影响制造新的散装材料和涂料的研制

1 能源，材料和资源的关注

关于在ECD＆M方法和技术的发展，在过去的十年里有了巨大的增长的研究。国家制造科学中心创造了一个对抗程序来识别和解决重大环境问题（例如，提高生活质量，帮助合作解决环境问题，工业和环境安全的替代品取代过时的和有害的程序）。使用两种方法来减少生产过程的环境影响：消除或减少有害物质的使用过程，并分析不同替代生产过程的废物的产生机制。在第一种方法中，大多数的研究主要集中在材料替代选择，而第二种方法试图改善制造过程的安全化学分离。在设计过程中，材料的选择可以帮助回收过程。好的材料和制造工艺的选择可以提高技术效率和生产力，以及减少对环境的影响。选择最合适的材料和工艺的任务由于几个原因非常复杂：1）在材料和工艺的可用数量快速增长；2）增加新的规格，数量应满足，包括经济和环境法规的限制；3）材料短缺，这需要一个搜索一个兼容的替代。博克提供材料和工艺的选择方法，使用一个交互式的专家系统，称为营（计算机辅助材料工艺的选择）。营设计者提供了一个工具选择的材料和工艺组合。该系统，使用查询和内置的规则，对一个设计师的逻辑选择一个特定的材料和工艺组合。Whitmer 2，奥尔森，萨瑟兰开发的两两比较的方法确定的设计时应注重什么部分，影响产品的需求决定的。这种方法提供了一个层次决定生产环保意识的产品，和样品进行了比较。这些决定包括：1）对零件材料的选择；2）数和紧固件使用的类型；3）接触的零件的润滑油；4）部分在一个组件之间的几何关系。从比较的结果被用来确定的设计工作，最大限度地提高相对于环境设计的有效性分布。

2 回收拆卸模型

在ECD＆M文学，许多研究人员强调循环结束（EOL）产品的重要性和产品拆卸回收的有效作用。循环是由jovane等人的定义。“回收材料或部件的产品使他们获得新的产品。”另一个定义是由班克罗夫特为“产品设计以促进产品和物料回收利用。“这些定义中的“闭合回路”的材料和组件重用他们在产品生命周期不同阶段的原材料或辅助材料使用后。

(1)循环

狼和艾伦说，造纸行业将作为其输出的50%倍之多。然而，在塑料工业中，只有一小部分被回收。狼和爱伦还报道说，有58000000000磅的塑料树脂在美国售出的小于1%的回收。石井，尤邦克斯，他提出了一个用于回收废旧产品产品退役模型设计。作者用“丛的概念，“这是一个集组件和组件共享一个共同的特点，根据设计者的意图。一个无形的效益回收所产生的是“绿色”的形象。回收废旧产品的其他重大利益会导致整个部件或组件的重用。例如，电子材料（如硅，锗，镓，铟）可以获利的回收，因为他们的高生产成本。许多工业过程已经提出了从电子元件提取这些有价值的元素。

回收要求的材料，并在丛的紧固方法与现有技术兼容。综述了各种金属henstack回收为基础的项目实践，侧重于废钢的汽车。研究产生的回收设计的一般性原则，包括简化机械拆卸，避免自我污染的材料组合，规范使用的材料，从钢项目分离铜含量高的项目。

与回收设计相关的两个工程问题拆解技术和回收成本。西蒙指出，拆除所需的知识的组成部件的目的地或拆卸回收的可能性。然而，从一个产品是为了达到其生命的结束时间，技术将在循环再造的先进。这种现象揭示EOL产品的回收困难。西蒙提出了解决该问题的两个原则：1）去除最有价值的部分的第一和2）最大化“屈服”每个拆解操作。

维腾堡提出的一个部件和材料的循环路径的概念，设想的宝马。它需要一个“瀑布模型”降低价值，其中注意力首先集中在拆卸零件适合重用具有最高的价值。电子废物的法令和二

手车迫使制造商回收废法令，重复使用可回收的馏分，和处理残渣。在汽车行业，宝马是回收和拆卸设计的领导者。Z1模型与一个塑料的皮肤，可以从金属底盘20分钟一二个座位的汽车。门，保险杠，前，后，侧面板是由可回收的热塑性塑料采用GE。的宝马3251也使用可回收的塑料配件及目标市场环境意识的客户。通过这些努力，宝马已确定一些指引，使拆卸和回收容易。

材料识别是回收的另一个有趣的方法。它需要一个能够识别材料技术，包括使用的比例和填充材料类型。理想的情况下，该技术应该是廉价的，手持使用不同的部件，和用于在一个车间式环境显著持久。一些研究人员已经在这方面的工作取得了不同程度的成功。舍戈尔德表明，傅里叶变换红外光谱的基础设备，虎和鸟是善于识别塑料和一些填充材料。

这是不可能的或经济的回收产品完全；因此，回收利用的目的是最大限度地利用资源的质量和剩余产品的潜力，减少污染。扎斯曼，Kriwet，和Seliger提出三个目标应该设计评估中考虑：1）利润最大化（效益）在一个产品的寿命；2）使用的零件数量最大化；和3）的量最小化（重量）的垃圾废物。

（2）拆卸

人们已经认识到，使用过的产品的拆卸是必要使循环经济可行的处理技术现状。

3安全和健康问题

另一个ECD＆M是安全和健康问题。在汽车、电子等行业，最常见的焊料的今天是由铅和锡（37%的铅和63%的锡）。然而，由于铅的极端毒性，它已被限制或禁止住宅油漆，汽油，和许多其他产品在过去的十年。因此，大量的研究集中在替代锡铅焊料与无铅或导电胶。

第二篇英文原文

Environmentally Conscious Design and Manufacturing

The research issues in ECD&M include: integration of product and process design with material selection systems,development of models for assessing the integration of consumer demand and

product use,disposal or recycling,improvement in methods,tools and procedures for evaluation of the risks associated with environmental hazards and the cost or benefit,substitution of materials with lower environmental impact in processing or in the final product,advancement in techniques for forecasting the effects of specific governmental regulations over the complete product life cycle,new or improved manufacturing processes,and development of new bulk materials and coatings with increased life spans that can be manufactured with decreased environmental impact.

1.Energy,Materials,and Resource Concern

Research concerning the development of methods and techniques in ECD&M has grown tremendously in the past decade.The National Center for Manufacturing Sciences created an ECM program to identify and solve major environmental problems(for example,to improve the quality of life,to help the industry collaboratively solving the environmental problem,and to replace obsolete and harmful procedures with environmentally safe alternatives).

Two approaches are used to reduce the environmental impact of manufacturing processes: eliminate or reduce the use of hazardous substances in the processes,and analyze the mechanisms of waste generation in different alternative manufacturing processes.In the first approach,most research focuses on the material substitution and selection,while the second approach attempts to improve the safety of manufacturing process.Material selection during the design process for chemical separation can be an aid to the recycling process.Good material and manufacturing process selection can improve technical efficiency and productivity,as well as reduce the environmental impact.The task of selecting the most suitable material and process has become very complex due to several reasons:1) rapid growth in the number of materials and processes available;2) increase in the number of new specifications to be satisfied,including economic and environmental regulatory constraints;and 3) materials shortages,which require a search for a compatible substitution. Bock provided a material and process selection methodology using an interactive expert system, called CAMPS(Computer-Aided Material Process Selection).CAMPS provide the designer with a tool for selecting the material and process combination.This system,using queries and built-in rules,simulates a designer's logic in choosing a particular material and process combination. Whitmer 2, Olson, and Sutherland developed the Pairwise Comparison Approach to determine what portion of the design time should be focused on decisions that affect the demand of products. This approach provides a hierarchy of decisions for producing an environmentally conscious product,and sample comparisons were made. These decisions include: 1)material selection for parts; 2)number and type of fasteners used; 3)lubricant used for parts in contact;and 4)geometrical relationship among parts within an assembly.Results from the comparisons are used to determine the distribution of the design effort that maximizes the effectiveness of the design with respect to the environment.

2.Recycling and Disassembly Modeling

In the ECD&M literature,many researchers emphasize the importance of recycling end-of-life (EOL) products and the role of product disassembly for effective recycling. Recycling is defined by Jovane et al.as"recovering materials or components of a used product to make them available for new products." Another definition was given by Bancroft as "the use of product design to facilitate the recovery and reuse of materials in the product." These definitions infer "closing the loop" of materials and components after usage by reusing them for raw materials or secondary materials at different stages of the product's life cycle.

(1) Recycling.

Wolf and Ellen reported that the paper industry recycles as much as 50% of its output. However, in the plastics industry, only a small portion is recycled. Wolf and Ellen also reported that there were 58 billion pounds of plastic resin sold in the United States and less than 1% of this was recycled. Ishii, Eubanks, and Marco proposed a design for a product retirement model for recycling EOL products. The authors used the concept of "clump," which is a collection of components and subassembly that share a common characteristic based on the designer's intent. One intangible benefit arising from recycling is the "green" image. The other significant benefit of recycling EOL products would result from reusing whole parts or subassemblies. For example, electronic materials (such as gallium, germanium, silicon, and indium) can be profitably recycled because of their high production cost. Many industrial processes have been proposed for extracting these valuable elements from electronic components.

Recycling requires that materials and fastening methods in the clump are compatible with existing technologies. Henstack reviewed recycling practices for various metal-based items, which

focuses on steel scrap in automobiles. The study has generated some general principles of design for recyclability, including simplifying mechanical disassembly, avoiding self-contaminating combinations of materials, standardizing materials used, and separating high copper content items from steel items.

Two engineering problems associated with design for recyclability are dismantling techniques and recycling costs. Simon pointed out that dismantling required the knowledge of the destination or recycling possibility of the component parts disassembled. However, from the time a product is designed to the time it reaches the end of its life, techniques will have advanced in recycling and reengineering. This phenomenon reveals the difficulties of recycling EOL products. Simon suggested two guidelines for dealing with this problem: 1)remove the most valuable parts first and 2) maximize the "yield" of each dismantling operation.

Wittenburg proposed the concept of a recycling path of components and materials, as envisaged by BMW. It entails a "cascade model" of decreasing values, in which attention is first focused on the disassembled parts suitable for reuse that have the highest value. The Decree on Electronic Waste and the Decree on Used Cars forced manufacturers to reclaim waste, to reuse the recyclable fraction, and to dispose of the residue. In the automobile industry, BMW is the leader in design for recycling and disassembly. The Z1 model is a two-seat automobile with an all-plastic skin that can be removed from the metal chassis in 20 minutes. The doors, bumpers, and front, rear, and side panels are made of recyclable thermoplastics produced by GE. The BMW 3251 also uses recyclable plastic parts and target-markets to environmental conscious customers. Through these efforts, BMW has identified some guidelines that make disassembly and recycling easier. Material recognition is another interesting approach of recycling. It requires a technology capable of identifying materials, including the proportion and type of filler materials used. Ideally, the technology should be cheap, hand-held for use on different components,and significantly durable for use in a workshop-type environment. A number of researchers have been working in this area with varying success. Shergold indicated that the Fourier Transform Infrared-based equipment that Rover and Bird developed is good at identifying plastics and some filler materials. It is not possible or economical to recycle a product completely; therefore, the aim of recycling is to maximize the recycle resources and to minimize the mass and pollution potential of the remaining products. Zussman, Kriwet, and Seliger proposed three objectives that should be considered during the design evaluation: 1) maximization of profit (benefits-costs) over a product's lifespan; 2) maximization of the number of parts reused; and 3) minimization of the amount (weight) of landfill waste.

(2) Disassembly.

It has been recognized that disassembly of used products is necessary to make recycling economically viable in the current state of the art of reprocessing technology. Disassembly is defined by Brennan, Gupta, and Taleb as "the process of systematic removal of desirable constitute parts from an assembly while ensuring that there is no impairment of the parts due to the process." There are both economic and environmental sound reasons for disassembly.

Many issues and research need to be addressed in the area of disassembly. The most significant technical challenge is how to design a product for easy disassembly. Designing a product with "easy"disassembly constraints as well as "easy" assembly constraints is likely to be a very difficult task. In the past, products and machines were designed with only the assembly operations considered. Some of the problems to be addressed during design stages are the following:

1) Ease of separation. Design for ease of separation, handling, and cleaning of all product components.

2) Fasteners. New fasteners should be developed, and the existing ones should be replaced by other fastening methods. Taking apart a snap-fitted or pop-in, pop-out product is much easier and requires less energy than taking apart a welded product.

3) Modularity design. The importance of using assemblies in a product's design is to ease dealing with a product after its useful life.

4) Material selection. The variety of material types must be minimized to increase the recyclability of the product. Highly recyclable materials such as aluminum and thermoplastics should be encouraged, while the use of thermosets, which cannot be recycled, should be minimized.

Research from the CIM Institute by Rose and Evans focused on disassembly-oriented lifecycle analyses, where recyclability of the product was evaluated under possible future trends in

recycling technology and economy. At the Swiss Federal Institute of Technology, an evaluation procedure has been proposed to support product design according to conflicting design for disassembly criteria. Each criterion is weighted and the final decision made taken on the basis of scaling all relevant criteria. Leonard reported that two basic methods of disassembly were used: reverse assembly and brute force. For reverse assembly, if a fastener is screwed in, then it is screwed out; if two parts are snap-fit together, then they are snapped apart. For brute force,parts are just pulled or cut.

Seliger, Zussman, and Kriwet stated that some obstacles make disassembly difficult for today's manufactured product. First, it is difficult to gain all the information necessary to plan the disassembly. Parts of the product might have been modified during repair, and wear can make joined elements difficult to remove. In addition, many consumer products are not designed for ease of disassembly. Engineers have done an outstanding job of meeting functional requirements and federal emission regulations. Traditionally, the engineers concentrated on improving productivity and made the product easier to be assembled. Fastening processes, such as welding and adhesive bonding, are permanent-type systems. However, engineers will now have to incorporate recyclability and disassembly into their designs when creating future products. Disassembly sequence is another problem encountered in the design for disassembly. The problems associated with the disassembly sequence are 1) freeing the part of all attachments; 2) finding the succeeding part in the disassembly sequence; and 3) disassembly of the succeeding part.

3.Safety and Health Issues

Another area with ECD&M is safety and health issues. Within the automotive and electronic industries, the most common solder being used today is composed of lead and tin (37% Pb and 63% Sn). However, because of lead's extreme toxicity, it has been restricted or banned from residential paints, gasoline, and numerous other products over the last decade. Therefore, much research has focused on the substitution of tin-lead solder with either non-lead or conductive adhesive.

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https://www.sodocs.net/doc/2e14111741.html,/finance/company/consumer.html Consumer finance company The consumer finance division of the SG group of France has become highly active within India. They plan to offer finance for vehicles and two-wheelers to consumers, aiming to provide close to Rs. 400 billion in India in the next few years of its operations. The SG group is also dealing in stock broking, asset management, investment banking, private banking, information technology and business processing. SG group has ventured into the rapidly growing consumer credit market in India, and have plans to construct a headquarters at Kolkata. The AIG Group has been approved by the RBI to set up a non-banking finance company (NBFC). AIG seeks to introduce its consumer finance and asset management businesses in India. AIG Capital India plans to emphasize credit cards, mortgage financing, consumer durable financing and personal loans. Leading Indian and international concerns like the HSBC, Deutsche Bank, Goldman Sachs, Barclays and HDFC Bank are also waiting to be approved by the Reserve Bank of India to initiate similar operations. AIG is presently involved in insurance and financial services in more than one hundred countries. The affiliates of the AIG Group also provide retirement and asset management services all over the world. Many international companies have been looking at NBFC business because of the growing consumer finance market. Unlike foreign banks, there are no strictures on branch openings for the NBFCs. GE Consumer Finance is a section of General Electric. It is responsible for looking after the retail finance operations. GE Consumer Finance also governs the GE Capital Asia. Outside the United States, GE Consumer Finance performs its operations under the GE Money brand. GE Consumer Finance currently offers financial services in more than fifty countries. The company deals in credit cards, personal finance, mortgages and automobile solutions. It has a client base of more than 118 million customers throughout the world

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本科毕业设计 外文文献及译文 文献、资料题目：Designing Against Fire Of Building 文献、资料来源：国道数据库 文献、资料发表（出版）日期：2008.3.25 院（部）：土木工程学院 专业：土木工程 班级：土木辅修091 姓名：武建伟 学号：2008121008 指导教师：周学军、李相云 翻译日期： 20012.6.1

外文文献: Designing Against Fire Of Buliding John Lynch ABSTRACT: This paper considers the design of buildings for fire safety. It is found that fire and the associ- ated effects on buildings is significantly different to other forms of loading such as gravity live loads, wind and earthquakes and their respective effects on the building structure. Fire events are derived from the human activities within buildings or from the malfunction of mechanical and electrical equipment provided within buildings to achieve a serviceable environment. It is therefore possible to directly influence the rate of fire starts within buildings by changing human behaviour, improved maintenance and improved design of mechanical and electrical systems. Furthermore, should a fire develops, it is possible to directly influence the resulting fire severity by the incorporation of fire safety systems such as sprinklers and to provide measures within the building to enable safer egress from the building. The ability to influence the rate of fire starts and the resulting fire severity is unique to the consideration of fire within buildings since other loads such as wind and earthquakes are directly a function of nature. The possible approaches for designing a building for fire safety are presented using an example of a multi-storey building constructed over a railway line. The design of both the transfer structure supporting the building over the railway and the levels above the transfer structure are considered in the context of current regulatory requirements. The principles and assumptions associ- ated with various approaches are discussed. 1 INTRODUCTION Other papers presented in this series consider the design of buildings for gravity loads, wind and earthquakes.The design of buildings against such load effects is to a large extent covered by engineering based standards referenced by the building regulations. This is not the case, to nearly the same extent, in the

建筑类外文文献及中文翻译

forced concrete structure reinforced with an overviewRein Since the reform and opening up, with the national economy's rapid and sustained development of a reinforced concrete structure built, reinforced with the development of technology has been great. Therefore, to promote the use of advanced technology reinforced connecting to improve project quality and speed up the pace of construction, improve labor productivity, reduce costs, and is of great significance. Reinforced steel bars connecting technologies can be divided into two broad categories linking welding machinery and steel. There are six types of welding steel welding methods, and some apply to the prefabricated plant, and some apply to the construction site, some of both apply. There are three types of machinery commonly used reinforcement linking method primarily applicable to the construction site. Ways has its own characteristics and different application, and in the continuous development and improvement. In actual production, should be based on specific conditions of work, working environment and technical requirements, the choice of suitable methods to achieve the best overall efficiency. 1、steel mechanical link 1.1 radial squeeze link Will be a steel sleeve in two sets to the highly-reinforced Department with superhigh pressure hydraulic equipment (squeeze tongs) along steel sleeve radial squeeze steel casing, in squeezing out tongs squeeze pressure role of a steel sleeve plasticity deformation closely integrated with reinforced through reinforced steel sleeve and Wang Liang's Position will be two solid steel bars linked Characteristic: Connect intensity to be high, performance reliable, can bear high stress draw and pigeonhole the load and tired load repeatedly.

有关隧道方面外文文献与翻译

A convection-conduction model for analysis of the freeze-thaw conditions in the surrounding rock wall of a tunnel in permafrost regions HE Chunxiong( 何春雄 )， (State Key Laboratory of Frozen Soil Engineering, Lanzhou Institute of Glaciology and Geocryology, Chinese Academy of Sciences, Lanzhou 730000, China; Department of Applied Mathematics, South China University of Technology, Guangzhou 510640, China) WU Ziwang( 吴紫汪 )and ZHU Linnan( 朱林楠 ) (State key Laboratory of Frozen Soil Engineering, Lanzhou Institute of Glaciology and Geocryology Chinese Academy of Sciences, Lanzhou 730000, China) Received February 8, 1999 Abstract Based on the analyses of fundamental meteorological and hydrogeological conditions at the site of a tunnel in the cold regions, a combined convection-conduction model for air flow in the tunnel and temperature field in the surrounding has been constructed. Using the model, the air temperature distribution in the Xiluoqi No. 2 Tunnel has been simulated numerically. The simulated results are in agreement with the data observed. Then, based on the in situ conditions of sir temperature, atmospheric pressure, wind force, hydrogeology and engineering geology, the air-temperature relationship between the temperature on the surface of the tunnel wall and the air temperature at the entry and exit of the tunnel has been obtained, and the freeze-thaw conditions at the Dabanshan Tunnel which is now under construction is predicted. Keywords: tunnel in cold regions, convective heat exchange and conduction, freeze-thaw. A number of highway and railway tunnels have been constructed in the permafrost regions and their neighboring areas in China. Since the hydrological and thermal

中英文文献翻译

毕业设计（论文）外文参考文献及译文 英文题目Component-based Safety Computer of Railway Signal Interlocking System 中文题目模块化安全铁路信号计算机联锁系统 学院自动化与电气工程学院 专业自动控制 姓名葛彦宁 学号 200808746 指导教师贺清 2012年5月30日

Component-based Safety Computer of Railway Signal Interlocking System 1 Introduction Signal Interlocking System is the critical equipment which can guarantee traffic safety and enhance operational efficiency in railway transportation. For a long time, the core control computer adopts in interlocking system is the special customized high-grade safety computer, for example, the SIMIS of Siemens, the EI32 of Nippon Signal, and so on. Along with the rapid development of electronic technology, the customized safety computer is facing severe challenges, for instance, the high development costs, poor usability, weak expansibility and slow technology update. To overcome the flaws of the high-grade special customized computer, the U.S. Department of Defense has put forward the concept：we should adopt commercial standards to replace military norms and standards for meeting consumers’demand [1]. In the meantime, there are several explorations and practices about adopting open system architecture in avionics. The United Stated and Europe have do much research about utilizing cost-effective fault-tolerant computer to replace the dedicated computer in aerospace and other safety-critical fields. In recent years, it is gradually becoming a new trend that the utilization of standardized components in aerospace, industry, transportation and other safety-critical fields. 2 Railways signal interlocking system 2.1 Functions of signal interlocking system The basic function of signal interlocking system is to protect train safety by controlling signal equipments, such as switch points, signals and track units in a station, and it handles routes via a certain interlocking regulation. Since the birth of the railway transportation, signal interlocking system has gone through manual signal, mechanical signal, relay-based interlocking, and the modern computer-based Interlocking System. 2.2 Architecture of signal interlocking system Generally, the Interlocking System has a hierarchical structure. According to the function of equipments, the system can be divided to the function of equipments; the system

土木工程外文文献翻译

专业资料 学院： 专业：土木工程 姓名： 学号： 外文出处：Structural Systems to resist (用外文写) Lateral loads 附件：1.外文资料翻译译文；2.外文原文。

附件1：外文资料翻译译文 抗侧向荷载的结构体系 常用的结构体系 若已测出荷载量达数千万磅重，那么在高层建筑设计中就没有多少可以进行极其复杂的构思余地了。确实，较好的高层建筑普遍具有构思简单、表现明晰的特点。 这并不是说没有进行宏观构思的余地。实际上，正是因为有了这种宏观的构思，新奇的高层建筑体系才得以发展，可能更重要的是：几年以前才出现的一些新概念在今天的技术中已经变得平常了。 如果忽略一些与建筑材料密切相关的概念不谈，高层建筑里最为常用的结构体系便可分为如下几类： 1.抗弯矩框架。 2.支撑框架，包括偏心支撑框架。 3.剪力墙，包括钢板剪力墙。 4.筒中框架。 5.筒中筒结构。 6.核心交互结构。 7. 框格体系或束筒体系。 特别是由于最近趋向于更复杂的建筑形式，同时也需要增加刚度以抵抗几力和地震力，大多数高层建筑都具有由框架、支撑构架、剪力墙和相关体系相结合而构成的体系。而且，就较高的建筑物而言，大多数都是由交互式构件组成三维陈列。 将这些构件结合起来的方法正是高层建筑设计方法的本质。其结合方式需要在考虑环境、功能和费用后再发展，以便提供促使建筑发展达到新高度的有效结构。这并

不是说富于想象力的结构设计就能够创造出伟大建筑。正相反，有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了，然而，如果没有天赋甚厚的建筑师的创造力的指导，那么，得以发展的就只能是好的结构，并非是伟大的建筑。无论如何，要想创造出高层建筑真正非凡的设计，两者都需要最好的。 虽然在文献中通常可以见到有关这七种体系的全面性讨论，但是在这里还值得进一步讨论。设计方法的本质贯穿于整个讨论。设计方法的本质贯穿于整个讨论中。 抗弯矩框架 抗弯矩框架也许是低，中高度的建筑中常用的体系，它具有线性水平构件和垂直构件在接头处基本刚接之特点。这种框架用作独立的体系，或者和其他体系结合起来使用，以便提供所需要水平荷载抵抗力。对于较高的高层建筑，可能会发现该本系不宜作为独立体系，这是因为在侧向力的作用下难以调动足够的刚度。 我们可以利用STRESS，STRUDL 或者其他大量合适的计算机程序进行结构分析。所谓的门架法分析或悬臂法分析在当今的技术中无一席之地，由于柱梁节点固有柔性，并且由于初步设计应该力求突出体系的弱点，所以在初析中使用框架的中心距尺寸设计是司空惯的。当然，在设计的后期阶段，实际地评价结点的变形很有必要。 支撑框架 支撑框架实际上刚度比抗弯矩框架强，在高层建筑中也得到更广泛的应用。这种体系以其结点处铰接或则接的线性水平构件、垂直构件和斜撑构件而具特色，它通常与其他体系共同用于较高的建筑，并且作为一种独立的体系用在低、中高度的建筑中。

冲压模具成型外文翻译参考文献

冲压模具成型外文翻译参考文献 (文档含中英文对照即英文原文和中文翻译) 4 Sheet metal forming and blanking 4.1 Principles of die manufacture 4.1.1 Classification of dies In metalforming,the geometry of the workpiece is established entirely or partially by the geometry of the die.In contrast to machining processes,ignificantly greater forces are necessary in forming.Due to the complexity of the parts,forming is often not carried out in a single operation.Depending on the geometry of the part,production is carried out in several operational steps via one or several production processes such as forming or blanking.One operation can also include several processes simultaneously(cf.Sect.2.1.4). During the design phase,the necessary manufacturing methods as well as the sequence and number of production steps are established in a processing plan(Fig.4.1.1).In this plan,the

仪表板外文文献翻译、中英文翻译、外文翻译

Dashboard From Wikipedia, the free encyclopedia This article is about a control panel placed in the front of the car. For other uses, see Dashboard (disambiguation). The dashboard of a Bentley Continental GTC car A dashboard (also called dash, instrument panel (IP), or fascia) is a control panel located directly ahead of a vehicle's driver, displaying instrumentation and controls for the vehicle's operation. Contents 1.Etymology 2.Dashboard features 3.Padding and safety 4.Fashion in instrumentation 5.See also 6.References Etymology Horse-drawn carriage dashboard Originally, the word dashboard applied to a barrier of wood or leather fixed at the front of a horse-drawn carriage or sleigh to protect the driver from mud or other debris "dashed up" (thrown up) by the horses' hooves.[1] Commonly these boards did not perform any additional function other than providing a convenient handhold for ascending into the driver's seat, or a small clip with which to secure the reins when not in use. When the first "horseless carriages" were constructed in the late 19th century, with engines mounted beneath the driver such as the Daimler Stahlradwagen, the simple dashboard was retained to protect occupants from debris thrown up by the cars' front wheels. However, as car design evolved to position the motor in front of the driver, the dashboard became a panel that protected vehicle occupants from the heat and oil of the engine. With gradually increasing mechanical complexity, this panel formed a convenient location for the placement of gauges and minor controls, and from this evolved the modern instrument panel,

土木工程类专业英文文献及翻译

PA VEMENT PROBLEMS CAUSED BY COLLAPSIBLE SUBGRADES By Sandra L. Houston,1 Associate Member, ASCE (Reviewed by the Highway Division) ABSTRACT: Problem subgrade materials consisting of collapsible soils are com- mon in arid environments, which have climatic conditions and depositional and weathering processes favorable to their formation. Included herein is a discussion of predictive techniques that use commonly available laboratory equipment and testing methods for obtaining reliable estimates of the volume change for these problem soils. A method for predicting relevant stresses and corresponding collapse strains for typical pavement subgrades is presented. Relatively simple methods of evaluating potential volume change, based on results of familiar laboratory tests, are used. INTRODUCTION When a soil is given free access to water, it may decrease in volume, increase in volume, or do nothing. A soil that increases in volume is called a swelling or expansive soil, and a soil that decreases in volume is called a collapsible soil. The amount of volume change that occurs depends on the soil type and structure, the initial soil density, the imposed stress state, and the degree and extent of wetting. Subgrade materials comprised of soils that change volume upon wetting have caused distress to highways since the be- ginning of the professional practice and have cost many millions of dollars in roadway repairs. The prediction of the volume changes that may occur in the field is the first step in making an economic decision for dealing with these problem subgrade materials. Each project will have different design considerations, economic con- straints, and risk factors that will have to be taken into account. However, with a reliable method for making volume change predictions, the best design relative to the subgrade soils becomes a matter of economic comparison, and a much more rational design approach may be made. For example, typical techniques for dealing with expansive clays include: (1) In situ treatments with substances such as lime, cement, or fly-ash; (2) seepage barriers and/ or drainage systems; or (3) a computing of the serviceability loss and a mod- ification of the design to "accept" the anticipated expansion. In order to make the most economical decision, the amount of volume change (especially non- uniform volume change) must be accurately estimated, and the degree of road roughness evaluated from these data. Similarly, alternative design techniques are available for any roadway problem. The emphasis here will be placed on presenting economical and simple methods for: (1) Determining whether the subgrade materials are collapsible; and (2) estimating the amount of volume change that is likely to occur in the 'Asst. Prof., Ctr. for Advanced Res. in Transp., Arizona State Univ., Tempe, AZ 85287. Note. Discussion open until April 1, 1989. To extend the closing date one month,