英文翻译原文

Engineering with Computers(2002)18:109–115

Ownership and Copyright

?2002Springer-Verlag London Limited

Structural Optimization of Automotive Body Components Based on

Parametric Solid Modeling

M.E.Botkin

GM R&D Center,Warren,MI,USA

Abstract

Abstract::Parametric modeling was used to build several models of an automotive front structure concept that utilizes carbon fiber composite materials and the corresponding molding processes.An ultra-lightweight aluminum body front structure was redesigned to include an all-composite front structure.Two alternative concepts were studied which represent the structure as a bonded assembly of shells.Closed sections result from two pieces–an inner and outer.Parametric modeling was found to be a useful tool for building and modifying models to use in optimization concept studies. Such models can be built quickly and both the sketch dimensions and location dimensions are particularly useful for making the adjustments necessary to fit the various body pieces together.The parametric models then must be joined together as one geometric solid model in order to obtain a surface mesh.Structural optimization input data can then be seamlessly and quickly created from the parametric-modelbased finite element model to begin the tradeoff studies.This integrated process in which parametric modeling was coupled with structural optimization was used to carry out design studies on the lightweight body front structure.Several carbon fiber material combinations were studied to determine mass reduction potential of certain types of carbon fiber products considered to be lower cost than typical carbon fiber materials used in the past.Structural optimization was used to compare several composite constructions for the design of the bonded front structure.Eight cases were studied using various materials and composite lay-ups.Mass savings estimates from45–64%over steel were obtained.The most reasonable design consisted of a combination of relatively low cost chopped carbon fiber and woven carbon fiber and using a20mm balsa core in the top of the shock tower area. This design had a maximum thickness of7mm and a mass reduction over steel of approximately62%.Correspondence and offprint requests to:Mark E.Botkin,Principal

Research Engineer,GM R&D Center,Mail Code:480-106-256,30500Mound Rd., Warren,MI48090-9055,USA.Email:mark.e.botkin_https://www.sodocs.net/doc/102934439.html,

Keywords:

Automeshing;Automotive;CAD Modeling;Composites;Finite Element Modeling; Optimization

1.Introduction

The structure shown in Fig.1is a lightweight body composed of several advanced materials.The design of this body was documented in Prsa[1]and was carried out as a part of the PNGV[2]government program.With the primary design goal being weight reduction,the PNGV body weighed approximately70%less than the Chrysler Cirrus steel body it is intended to replace.The body is primarily composed of a sandwich construction of carbon fiber skins and aluminum honeycomb.Small amounts of Kevlar were also used as well as some Nomex core.However,the load-carrying members of the front structure are aluminum.This paper describes a project to redesign an all-carbon fiber front structure.Several concepts were considered.The concepts described in this paper can be characterized as bonded-together sheets that form closed-section rails.The concepts were modeled using the parametric modeling features of

Unigraphics (UG)[3],and are shown in the next sections.The mesh was created automatically using the Scenario capability of Unigraphics.

Fig. 1.Carbon fiber body.

Because the mesh was created based upon a solid geometric model,separate property regions were automatically created for each surface face.This made the optimization data creation phase much easier than previous studies[4].Programs such as Patran[5]can create optimization data automatically from properly created structural analysis data.This paper also describes the use of Nastran[5]Solution200to carry out design studies for composite

design concepts for the front-end structure.

2.Parametric Modeling

The parametric modeling process begins with two-dimensional parametric cross-sections which are used to create solid models through extrusion along a straight line or sweeping along a curve.The front structure shown in Fig.1was modeled,using this parametric process,as bonded-together composite sheets.The model is composed,primarily,as three major components;the upper rail,lower rail,and shock tower.Other secondary panels tie these three components together.As an example,Fig.2shows the parametric cross section of the outer piece of the upper rail.The dimensions shown are variables that can be changed either by the designer using the modeling program or automatically using optimization procedures.After a variable is modified,the entire solid model is automatically updated.Figure3shows the process of creating three-dimensional geometry from the two-dimensional sections.As the section is swept along the curve, solid geometry is automatically generated.When any of the underlying information is modified,e.g.,section dimensions,sweep curve location,etc.,the solid geometry is

Fig.2.Outer piece of upper rail.

automatically updated.Similar operations are used for the lower rail and the shock tower to obtain the complete parametric solid model that will be used in this design study, shown in Fig.4.Figure4represents a three piece composite structure(upper rail,lower rail,and shock tower/apron)joined together with adhesive.For the purposes of this design study,parametric modeling was only used as a convenient method to create the

finite element model.Ultimately,however,a more comprehensive design approach would allow the parametric model to be an integral part of optimization process where

the parametric dimensions are available to be used as design variables.This is possible,to a large extent,with versions of Unigraphics16and later and has been demonstrated in Botkin[6].

3.Finite Element Analysis

3.1.Mesh Generation

The mesh shown in Fig.5was created from UG Scenario using the fully-automatic quadrilateral mesh generation capability using a nominal10mm element size.This is an advancing front technique typical of those found in most commercial modeling programs. However,because of the tight integration between the parametric modeler and the mesher, the distinct surface regions shown in Fig.4are maintained as property regions in the mesh and,as shown in Fig.6,can be automatically specified as design variables in the optimization model.The model shown in Fig.5is composed of11,710nodes,12,225 elements,58,877degrees-of-freedom,and23different element properties.In addition to 11488shell elements,737CBAR elements were used to represent adhesive bonds that were used to join the composite pieces together.

3.2.Analysis Model

Figure5also shows the load and boundary conditions used in this study.The goal of this optimization study is to design an all-composite front structure to have the same stiffness as the composite/aluminum structure shown in Fig.1.The torsional stiffness of the structure in Fig.1was found to be[1]10,246N·m/deg.It was found by an analysis of the shock tower region that the stiffness is much higher than that of the overall body at

17,963N/mm in the vertical direction and111Structural Optimization of Automotive Body Components

Fig. 3.Tapered upper rail.

Fig.4.Final front structure model.

Fig.5.Final mesh from UG/Scenario.

Fig.6.Material property regions.

12,941N/mm in the lateral direction.That corresponds to a limiting deflection of.055

mm for the1000N load shown in Fig.5and.077mm for a similar lateral1000N load.

3.3.Bond Modeling

As noted earlier,the three individual composite pieces are to be joined by the use of

adhesives.Figure7shows the modeling approach chosen for this study.The rows of elements along the edges of each piece are joined by the use of beam elements for which the properties are determined from the material properties of the adhesive(shown in Table1).The beam properties are the area of the bond considered to contribute to nodes A and B(see Fig.7)and the moments of inertia.These values are50mm2and416.67 mm4,respectively,assuming a nominal element size of10mm(square).

https://www.sodocs.net/doc/102934439.html,posite properties[4]

4.Optimization Studies

Nastran Solution200was used to carry out eight case studies of various combinations of materials.The material properties are given in Table1.All of the default Nastran optimization parameters[7]were used except the approximate optimization technique which was chosen to be Convex Linearization[8,9].As noted in Botkin[4],convex linearization,which is the most conservative of the approximation methods available in

Nastran,was used because of the difficulty of approximating the failure constraints.

4.1.Objective and Constraint Functions

The objective function of the studies was minimum mass.The design was,as mentioned earlier,for stiffness-only.Constraints were imposed on the lateral and vertical deflections of0.077and0.055mm,respectively.

4.2.Design Variables

As mentioned previously,the design variables can automatically be created from the property regions shown in Fig.6.Figure8shows the panel from Patran[5]which is displayed when the Design Study tool is used.Although there are23design variables,not

all are shown on a single panel.Initial values can be modified using this panel and then

the Solution200data input(DESVAR&DVPREL1card images)is automatically created.It should be113Structural Optimization of Automotive Body Components

Fig.8.Design variable panel.

pointed out that the thickness values shown in Fig.8are the initial values of10mm for the optimization run.The30mm values for the PCOMP entries include a10mm balsa core and two10mm composite face sheets.Although the optimization method used in this design study,Nastran Solution200,is capable of treating composite ply-angle variables–as was demonstrated in Botkin[4]–only woven cloth with a fixed,90angle

was used in an effort to reduce fabrication costs.

4.3.Design Concept Selection

Although Fig.4is referred to as a design concept,the parametric solid model can be thought of as a geometrical concept as opposed to a composite design concept.The goal of this design study is to use lower cost carbon fiber products such as chopped fiber and the less expensive large tow products.Estimated properties for these composites can be seen in Table1along with properties of all materials used for this study.The lower bound on all design variables was set at2mm which is considered to be the thinnest parts that can currently be molded using liquid molding processes.The cases are separated into three groups by upper bounds:15,10,and_10mm.These thicknesses represent the succession of studies that took place in an effort to find a design with a suitably small maximum thickness.The mass histories of all cases and the thickness distributions are summarized in Figs9and10,respectively.It would be most desirable for a capability to

exist that would determine an optimum composite concept rather than having to compare several selected concepts.Existence of such a capability is not known to the author.

Fig.9.Mass summary of cases.

Fig.10.Converged design variables.

4.4.15mm Upper Bounds

Case1

The first case will be that of using all chopped carbon material with no sandwich construction.This would be considered to be the least expensive case using the cheapest material and having no core.Cores add to the material and processing cost and are difficult to mold.As with all cases there will be23design variables and a displacement constraint will be placed at the top of the shock tower to maintain the target stiffness shown previously.A preliminary analysis has shown that the initial design violates the displacement constraint by33%.Figure9shows the mass history of this case.Although the initial stiffness target was violated at approximately13.6kg,the optimizer was able to find a design that satisfied the stiffness target at6.2kg,or64%(6.2kg/64%)mass

reduction over the estimated steel mass.Considering this is a relatively low performance

material,these results are remarkable.Figure10shows the design variable distribution of this case.The initial thickness of all design variables was10.0mm.Several of the variables terminated at their lower bounds of2.0mm which is considered to be the smallest thickness that can be reasonably molded using Resin Transfer Molding(RTM) or Structural Reaction Injection Molding(SRIM).Several variables,however,ended at the arbitrarily chosen upper bound of15mm.It should be pointed out that the variables which terminated at their upper bounds were more sensitive(in a mathematical sense)to the constraint than the mass.The remainder of the variables are more sensitive to mass than the constraint and hence provide the opportunity for mass reduction.A15mm thickness is considered to be a rather unrealistic value and leads to a conclusion that the material in those regions needs to be either higher performing or of a sandwich

construction,which leads to Case2.

Case2

This case adds a10mm thick balsa core of1.0g/cm3(6.5lb/cf)density to the top of the shock tower,i.e.,variables7and10through13as shown in Fig.6.Due to the added stiffness,the initial design in this case is7.8%stiffer than the target value.Figure9 shows the mass history of this case.Although the initial design was stiffer,the initial mass was higher due to the weight of the core and

the added face sheet.In addition,even the final design was heavier than in Case1(6.62 kg/61.3%).As demonstrated in Botkin[4]when skin thicknesses are very large, sandwich construction may not be effective.Figure10also shows the variable distributions.Although several of the variables are driven to their upper bounds,most

other variables are smaller than in Case1.

Case3

This case modifies the surface skin in the sandwich panel(top of shock tower)to a higher performing material.This will be a woven material in which the properties are shown in Table1.It is assumed that this material will be made from the low cost50K tow carbon fiber.Figure9shows the results of this case.As can be seen the final mass is only

slightly larger(6.65kg/61.2%)and the thicknesses have not been reduced,as was desired.

Even though the elastic modulus is much greater for the weave,the shear properties are much lower.

4.5.10mm Upper Bounds

The following cases show the effect of reducing the upper bound on thickness to10mm. It is considered that15mm is excessively thick to be a reasonable construction.As one

might expect the optimal mass increased in all cases.

Case4

This case maintains the all-chopped carbon but with a core.(9.35kg/45.4%).

Case5

This case uses woven material in the shock tower area(9.09kg/46.9%).

Case6

This case uses two layers of woven material.The outer layer is0°–90°and the inner layer is_45°in order to improve the shear properties of the woven material.This construction had the desired effect of reducing the mass significantly from the other two 10mm cases.(7.95kg/53.6%).

4.6._10mm Upper Bounds

Case7

This case is an extension of case6with a20mm core of1.5g/cm3(9.5lb/cf)density and an upper bound on material thickness of7mm.The MTC body also used a20mm core but of aluminum honeycomb.This case resulted in a mass of6.55kg or61.8%mass reduction over steel.This is a very reasonable design with maximum thicknesses well

within the range of practical consideration.

Case8

This case adds sandwich construction(a10mm balsa core)to design variable regions17 and18shown in Fig.6.The results of Case7indicated these regions to be at their upper bounds.Furthermore,as shown in Fig.1,the shock tower also used sandwich construction in the side walls.Just as in Cases6and7woven material was used with the same lay-up.The results of this case were very encouraging in that an upper bound of6 mm was obtained.Although the optimal mass is greater than in Case7(6.95kg/59.4%), if maximum thickness is an issue,this case may be more desirable.

4.7.Strength Constraints

Case9

In this case,two loading conditions are added to include strength constraints to the stiffness-only design(Case8).The first load condition represents the average barrier loads from a35mph(56.3km/hr)crash applied at the upper(10,000N)and115 Structural Optimization of Automotive Body Components lower rails(44,000N),each side.The second loading condition represents a commonly-used3g pothole load(6675N) applied vertically at the shock tower.Constraints were imposed on stresses for the chopped carbon and failure indices[4]for the woven material.Since the tensile and compressive strengths of the chopped carbon were different,the more conservative limit

of150Mpa was used as the stress constraint.For the failure index(Hoffman),a value of 1.0was used as the constraint limit.The results of this case are shown as Case9in Figs9 and10.Because the stiffness constraints are very severe for this lower-stiffness material, the stress constraints did not play a very important role in the design(7.1kg/58.6%) compared to case8.It is still,however,important to determine if the stiffness-only

designs are realistic.

4.8.Case Summary

Case7appears to be the best design.This case uses the less costly chopped carbon in all areas except for the top of the shock tower where two layers of woven or stitched mat material is used in conjunction with a20mm balsa core.This type of reinforcement can also be obtained from the cheaper,large-tow carbon fiber and has been shown to have similar properties.The mass reduction is61.8%over the steel structure compared with a 68%for the PNGV front structure that,as pointed out earlier,was fabricated from very costly aerospace-like materials and processes.

5.Summary and Conclusions

Parametric modeling coupled with structural optimization was used to carry out design studies on a

lightweight body front structure.A tightly-coupled parametric structural design process was described in which no manual data preparation–beyond the parametric model description–is necessary.Parametric modeling was used to build several models of an automotive front structure concept which utilizes carbon fiber composite materials and

the corresponding molding processes.Two alternative concepts were studied–only one concept was shown in this paper–which represent the structure as an adhesively bonded assembly of shells.Closed sections result from two pieces–an inner and outer.

An ultra-lightweight body designed for PNGV was redesigned to include an all-composite front structure.Several carbon fiber material combinations were studied to determine mass reduction potential of certain types of carbon fiber products considered to be lower cost than typical carbon fiber materials used in the past.Structural optimization was used to compare several composite constructions for the design of the bonded front structure.Nine cases were studied using various materials and composite lay-ups.Mass savings estimates from45%to64%over steel were obtained.The most reasonable design consisted of a combination of chopped carbon fiber and woven carbon fiber and using a 20mm balsa core in the top of the shock tower area.This design had a maximum thickness of7mm and a mass reduction over steel of approximately62%.It was also found that adding strength constraints had very little effect on the designs.

References

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2.Partnership for a New Generation of Vehicle Home Page.https://www.sodocs.net/doc/102934439.html,/pngv/

3.UNIGRAPHICS online documentation,Version15.

https://www.sodocs.net/doc/102934439.html,/docs/unigraphics.html

4.Botkin,M.E.(2000)Modeling and optimal design of a carbon fiber reinforced composite automotive roof,

Eng.with Comput.16(1),16–23

5.MSC PATRAN online documentation,Version70.5(1999)The MSC.Software Corporation

6.Botkin,M.E.(2000)An Assessment of Design Optimization in Unigraphics Version 16.GM R&D

Publication R&D-9100

7.Moore,G.J.,Design Sensitivity and Optimization.MSC/NASTRAN?User’s Guide

8.Starnes,J.H.,Haftka,R.T.(1979)Preliminary design of composite wings for buckling,strength,and displacement constraints.J.Aircraft16(8),564–570

9.Fleury,C.,Braibant,V.(1986)Structural optimization–a new dual method using mixed variables.Int.

J.Numer.Meth.Eng.23(3),409–428

英语原文及其翻译

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文献翻译英文原文

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英文翻译(原文)

GRA VITY RETAINING?WALL 1. INTRODUCTION Retaining walls are structures used to provide stability for earth or other material where conditions disallow the mass to assume its natural slope, and are commonly used to hold back or support soilbanks,coal or ore piles, and water. Retaining walls are classified, based on the method of achieving stability, into six principal types (Fig.1). The gravity-wall depends upon its weight, as the name implies, for stability. The cantilever wall is a reinforced-concrete wall that utilizes cantilever action to retain the mass behind the wall from assuming a natural slope. Stability of this wall is partially achieved from the weight of soil on the heel portion of the base slab. A counterfort retaining wall is similar to a cantilever retaining wall, except that it is used where the cantilever is long or for very high pressures behind wall and has counterforts, which tie the wall and base together, built at intervals along the wall to reduce the bending moments and sheers. As indicated in Fig.1c, the counterfort is behind the wall and subjected to tensile forces. A buttressed retaining wall is similar to a counterfort wall, except that the bracing is in front of the wall and is in compression instead of tension. Two other types of walls not considered further are crib walls, which are built-up members of pieces of precast concrete, metal, or timber and are supported by anchor pieces embedded in the soil for stability, and semigravity walls, which are walls intermediate between a true gravity and a cantilever wall. (a)(b)(e)

英语原文及翻译

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水文与水资源专业英语文章翻译

3单元 地下水位的高低可在一年内大幅波动，下降和上升后，在干燥的季节，降水期。因此，为了保证连续供水，井应穿透许多米水位以下。当水从井里抽水，它在水面产生抑郁，大致锥形的形状，称为漏斗。如果抽重，水表不仅可以降低周围的好但还可延伸到大面积。这在美国西部的部分是这样的。在这种情况下，可以说，地下水被“开采”。即使抽人立即停止，它可能需要数百年的地下水得到补充。下面的例子说明了这一点： 例如，在干燥的美国西南部，含水层补给是每年只有1英寸深的水的十分之二点位置。在这些地区，这是不寻常的泵两英尺或更多的水用于灌溉和其他用途的每年。在这个简单的例子，如果整个含水层抽水的速度，每年的开采量将相当于120年和十年的补给，泵将1200年积累的水。在泵送期间新补给可以忽略不计。机械问题和经济因素阻止完全脱水的含水层，但原则上是有效的例子。 短期承压是适用于任何情况，地下水位上升，在一个以上的水平，这是最初遇到的。这样的情况发生，两个条件必须满足：（1）水，必须限制在一个含水层，是倾斜的，一端暴露在表面，在那里可以得到水；和（2）防渗层，上面和下面的含水层，必须防止水逃避，这样一层被窃听，被上面的水的重量产生的压力会使水上升。如果没有摩擦，井里的水会上升到顶部的水位。含水层。 自流系统作为管道，将水从很远的偏远地区的充电放电点。这样水倒在威斯康星州中部年前现在是从地面和社区许多英里远，伊利诺斯。在南达科他州这样的系统已经从西部的黑山带水，向东跨越国家。在不同的尺度上，城市供水系统可能是人为的自流系统的例子。水塔，为抽水，可能是补给区，管道的承压含水层，在家中的自流井的水龙头。 4单元 矿产勘查在世界表明温度在深油、矿产品通常会增加在地表以下深度增加。在这样的情况下增加温度约0.6度，平均每30米。因此，当地下水在深循环，它变得激烈，如果它上升到表面，水是温泉。一些温泉水在美国，特别是在东部，加热这种方式。在美国，绝大多数的温泉发现于西方。这种分布的原因是，大部分温泉的热源是冷却的火成岩，它是在西方，火成活动已经最近。 间歇泉是间歇性的温泉或喷泉，水柱喷射的伟大力量在不同的时间间隔，通常上升30-60米。水流停止后，一列蒸汽冲出，通常以雷鸣般的轰鸣声。这或许是世界上最著名的间歇泉是黄石公园的老忠实喷发，大约每小时一次。间歇泉也在世界的其他地区，包括冰岛和新西兰，在那里长期间歇泉，意为“喷泉”或“井喷”这个词。 间歇泉时，地下水是地下室加热。室底部，水在巨大的压力下，由于上覆水的重量。因此，一个100度以上的温度就会沸腾所需的前。例如，在一个300米的室内水下必须达到一个温度近230度才开。加热使水膨胀，其结果是某些流出的顶部。这减少了压力，和水变成蒸汽，使间歇泉喷发。 从温泉和间歇泉地下水通常包含在解决方案比其他来源的地下水多材料因为热水比冷水更有效的溶解。当水中含有大量溶解的二氧化硅，硅华沉积在春天。石灰石，方解石的一种，是在石灰岩地区温泉特色存款。一些温泉含硫磺。除了使水的味道不好，硫发出难闻的气味。毫无疑问，臭蛋的春天，内华达州，这种情况。 11单元 一种污染物，是任何物质，生物或化学。在一个可识别的过量的有害的其他理想的生物。在这个框架内，过量的重金属如发汞；某些放射性同位素；氮，磷，钠；和其他有用的，甚至是必要的元素，以及某些致病性细菌和病毒污染物。在某些情况下，材料可作为一种污染物，世界人口中的一段特别的虽然它对其他部分不被认为是有害的。例如，在适当的复合氮超标有害于婴儿，但少了很多成年人如果在所有。在这样的方式，过多的钠盐通常不是有害的，但它可以制约医疗原因盐的摄入饮食的某些人。 不同的物理，地质，生物环境与地下水污染与地表水污染相比是显著的。在后者中，流量和氧气和阳光可用液压，随着速度的过程中污染物的稀释和扩散发生，明显不同于地下水，在污染物降解菌的机会通常局限于土壤或几英尺以下。此外，通过何种渠道地下水运动是非常小的和可变的。由此，显而易见的是，移动速度大大降低，除非，也许，在大的解决渠道内石灰石，以及分散和稀释的机会是非常有限的。此外，地下水通常缺乏氧气，这是造成好氧微生物的种类有帮助但这可能提供了一个“幸福之家”厌氧品种。 大多数土壤和岩石物理过滤出固体的能力，包括污染的固体，是公认的。然而，这种能力会随不同的大小，形状，和滤料颗粒的安排，在选定的沙子和其他材料在水过滤厂使用证明。也知道，但也许不那么普遍，是粘土和其他矿物捕获和交换的一些元素和化合物的能力时，他们游离在溶液中的正或负电荷的元素或化合物。这样的交流，随着吸附和沉淀过程中，污染物的捕获是重要的。这些过程有能力定义的单位是可逆的。他们也可以很容易地在设计设施正确的污染问题所依托的地质环境，土壤和岩石忽视治疗；这种疏忽可能造成地下水污染。这是特别重要的在污水土地应用。 很多猜测，争论，研究发生的地下水污染。地下水污染的主要关注的是化学元素，化合物的引入，和微生物，不含水层，可用于饮用水或是自然发生的，不仅因为该含水层的降解也因为在检测的难度，长期居住，和难度和费用含水层恢复。强有力的论点是，任何废物或可能的污染物应允许进入地下水系统的任何部分。这是一个不可能实现的梦想。相反，答案在于更多的了解自然过程处理废弃物的保证时，土壤和岩石是不能够处理，存储，或回收废物，我们可以发展过程使污染物处理，储存，或可回收。 Extracting and distinguishing environmental change information with high resolution form groundwater and sediments of groundwater system has been the major trend of groundwater sciences towards environmental sciences, This is very useful for forecasting environmental change.4从地下水及其沉积物中提取高分辨率的环境变化信息，实现对环境变化的预警功能是地下水科学向环境科学延伸的重要方向。5而随着全球淡水资源紧缺的形势不断恶化，全球环境变化，特别是全球气候变化对地下水资源的影响成为水文地质研究的新课题。5 With fresh water shortage increasingly serious, the research on effect of globle environmental change, especially globle climate change in groundwater resource has become a new area for hydrogeological research. 4depleted in K and SO4 井的出水量与含水层的渗透系数成正比。 Well water yield is proportional to the transmissivity of a aquifer. 1、分布在这个深层碳酸岩含水层中的地下热水的温度是60℃-90℃。 2、Temperature of the thermal groundwater in the deep-seated carbonate aquifer occurring in this area ranges from 60℃ 3、所有观测井水位的季节性波动可以用研究区降水量的季节性变化来解 4、Seasonal fluctuations in water table in observation wells are interpreted by seasonal changes of/in precipitation in study areas.

科普版英语六年级下册课文及翻译 (直接打印版)

Lesson 1 I’m not feeling well. Let’s talk （M=Mom, T= Tom） M: What,'s the matter, Tom T: I'm not feeling well, Mom M: Do you have a cold T: Yes, I think so. Could you give me some water, please M: Here you are. T: Thank you, Mom. M: Tom, you must go and see a doctor. T: OK, Mom. M: It's cold outside. You must wear your coat. T: OK, Mom. Could you pass me my coat,please M: Here you are. T: Thank you, Mom M: Tell me your teacher's number. I'll call him and tell him you are sick. T: OK. Here it is. 译文 (M=妈妈,T=汤姆) 妈妈:怎么了,汤姆 汤姆:我感觉不舒服,妈妈。 妈妈:你感冒了吗 汤姆:是的,我想是这样的。您能给我一些水吗 妈妈:给你。 汤姆:谢谢您,妈妈。 妈妈:汤姆,你必须去看医生. 汤姆:好的,妈妈。 妈妈:外面很冷。你必须穿你的外套。 汤姆:好的,妈妈。您能把我的外套递给我吗 妈妈:给你。 汤姆:谢谢您,妈妈。 妈妈:告诉我你老师的电话号码。我将给他打电话告诉他你生病了。

英语翻译专业必翻经典文章英文原文参考译文

文档简介 一，英语翻译经典文章之英文原稿二，中文翻译：这篇英语文章的最好翻译版本！不是俺说的，是俺老师说哒！！ 英文原稿Brian It seems my only request (“please, let me sleep”) is not clear enough, so I made this simple table that can help you when you’re in doubt. Especially during the night

中文翻译小子： 我只想好好地睡觉，你不明白吗？！所以，我做了这个简表。当你不知道怎么办时，特 别是在晚上的时候，你可以看看它。 具体情况行动指南 1，我正在睡觉禁止进入 2，你不确定我是否睡觉，你想搞清楚管你“鸟”事；禁止进入 3，你嗑了药，想奔向我的床你他妈的滚远点 4，你在youtube上看了一个超赞的视频，禁止进入；在脸书上把链接发给我想让我看看 5，就算第三次世界大战开始了管我屁事，他妈的别进来 6，你和你的基友们想和我“玩玩”抱歉，直男一枚。不要碰我的任何东西，门都别碰 7，你想整理我的房间我谢谢你了！我自己会打扫 8，普京宣布同性婚姻合法化终于等到“它”！还好你没放弃！还是不要来我房里！ 9，我不在家进我房间，想都别想 10，白天，我在家。你敲了门，我说“请进” 你可以进来了 福利放送！！

如果你已经看到了这里，那么说明你应该是英文爱好者哦。 下面有一些非常实用，我精心整理的英文资料，你一定用得到！快去看看吧！ 一，最常用英语翻译政治文体句型总结大全完美版 二，英文合同翻译最常用句型总结专业版 三，英语毕业论文提纲模板优秀完整详细无敌版

土木工程专业英语课文原文及对照翻译

土木工程专业英语课文原 文及对照翻译 Newly compiled on November 23, 2020

Civil Engineering Civil engineering, the oldest of the engineering specialties, is the planning, design, construction, and management of the built environment. This environment includes all structures built according to scientific principles, from irrigation and drainage systems to rocket-launching facilities. 土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。 Civil engineers build roads, bridges, tunnels, dams, harbors, power plants, water and sewage systems, hospitals, schools, mass transit, and other public facilities essential to modern society and large population concentrations. They also build privately owned facilities such as airports, railroads, pipelines, skyscrapers, and other large structures designed for industrial, commercial, or residential use. In addition, civil engineers plan, design, and build complete cities and towns, and more recently have been planning and designing space platforms to house self-contained communities. 土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。 The word civil derives from the Latin for citizen. In 1782, Englishman John Smeaton used the term to differentiate his nonmilitary engineering work from that of the military engineers who predominated at the time. Since then, the term civil engineering has often been used to refer to engineers who build public facilities, although the field is much broader 土木一词来源于拉丁文词“公民”。在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。 Scope. Because it is so broad, civil engineering is subdivided into a number of technical specialties. Depending on the type of project, the skills of many kinds of civil engineer specialists may be needed. When a project begins, the site is surveyed and mapped by civil engineers who locate utility placement—water, sewer, and power lines. Geotechnical specialists perform soil experiments to determine if the earth can bear the weight of the project. Environmental specialists study the project’s impact on the local area: the potential for air and

英文翻译原文

南京师范大学泰州学院 英文翻译原文 年级： 2011级学号：12110330 姓名：申佳佳 系部：信息工程学院 专业：通信工程 题目：基于C51的数字测速仪设计与仿真 指导教师：焦蓬蓬 2015 年 4 月 5 日

Linux - Operating system of cybertimes Though for a lot of people , regard Linux as the main operating system to make u p huge work station group, finish special effects of " Titanic " make , already can be re garded as and show talent fully. But for Linux, this only numerous news one of. Rece ntly, the manufacturers concerned have announced that support the news of Linux to i ncrease day by day, users' enthusiasm to Linux runs high unprecedentedly too. Then, Linux only have operating system not free more than on earth on 7 year this piece wh at glamour, get the favors of such numerous important software and hardware manufa cturers as the masses of users and Orac le , Informix , HP , Sybase , Corel , Intel , Net scape , Dell ,etc. , OK? 1.The background of Linux and characteristic Linux is a kind of " free (Free ) software ": What is called free, mean users can o btain the procedure and source code freely , and can use them freely , including revise or copy etc.. It is a result of cybertimes, numerous technical staff finish its research a nd development together through Inte rnet, countless user is it test and except fault , c an add user expansion function that oneself make conveniently to participate in. As th e most outstanding one in free software, Linux has characteristic o f the following: (1)Totally follow POSLX standard, expand the network operating system of sup porting all AT&T and BSD Unix characteristic. Because of inheritting Unix outstandi ng design philosophy , and there are clean , stalwart , high-efficient and steady kernels , their all key codes are finished by Li nus Torvalds and other outstanding programmer s, without any Unix code of AT&T or Berkeley, so Linu x is not Unix, but Linux and Unix are totally compatible. (2)Real many tasks, multi-user's system, the built-in n etwork supports, can be with such seamless links as NetWare , Windows NT , OS/2 , Unix ,etc.. Network in various kinds of Unix it tests to be fastest in comparing and ass ess efficiency. Support such many kinds of files systems as FAT16 , FAT32 , NTFS , E x t2FS , ISO9600 ,etc. at the same time .