A NOVEL INTEGRATED SYSTEM FOR RAPID PRODUCT DEVELOPMENT
This paper presents a novel integrated system of rapid product development for reducing the time and cost of product development. The system is composed of four building blocks —digital prototype, virtual prototype, physical prototype and rapid tooling manufacturing system. It can aid effectively in product design, analysis, prototype, mould, and manufacturing process development by integrating closely the various advanced manufacturing technologies which involve the 3D CAD, CAE, reverse engineering, rapid prototyping and rapid tooling. Furthermore, two actual examples are provided to illustrate the application of this integrated system. The results indicate that the system has a high potential to reduce further the cycle and cost of product development.
Keywords: Rapid product development; rapid prototyping; integrated system.
1. Introduction
Due to the pressure of international competition and market globalization in the 21st century, there continues to be strong driving forces in industry to compete effectively by reducing manufacturing times and costs while assuring high quality products and services. Current industries are facing the new challenges: quick response to business opportunity has been considered as one of the most important factors to ensure company competitiveness; manufacturing industry is evolving toward digitalization, network and globalization. Therefore, new products must be more quickly and cheaply developed, manufactured and introduced to the market. In order to meet the demand of rapid product development, the various new technologies such as reverse engineering (RE), 3D CAD, rapid prototyping (RP), and rapid tooling (RT) have emerged and are regarded as key enabling tools with the ability to shorten the product development and manufacturing time. For example, it has been claimed that RP can cut new product development costs by up to 70% and the time to market by 90%.1 In the form of a better design, more design possibilities, a 3D CAD model can be shown to the customer for approval and prevents misunderstandings. A virtual prototyping is employed to guide in optimization of the
product design and manufacturing process planning, which may result in the accurate determination of the process parameters, and reduce the number of costly physical prototype iterations. Rapid tooling technique offers a fast and low cost method to produce moulds, and shows a high potential for faster response to market demands. When properly integrated among 3D CAD, CAE, RE, RP and RT, these technologies will play a much more important role to reduce further the development cycle and cost of the product production. On the basis of above technologies, a novel integrated system of rapid product development is to be founded so as to meet the requirement of rapid product development.
2. Architecture of the Integrated Development System
The development process from initial conceptual design to commercial product is an iterative process which includes: product design; analysis of performance, safety and reliability; product prototyping for experimental evaluation; and design modification. Therefore, any step of the new product development process has a direct and strong influence on time-to-market in short order. A good product development system must enable designers or design teams to consider all aspects of product design, manufacturing, selling and recycling at the early stage of the design cycle. So that design iteration and changes can be made easily and effectively. The more fluent the feedback is the higher possibility of success the system has. Design for manufacturing (DFM) and concurrent engineering (CE) necessitate that product and process design be developed simultaneously rather than sequentially.
The integrated system of rapid product development is composed of four modules: digital prototype, virtual prototype, physical prototype and rapid tooling.The product development starts from the creation of a 3D CAD model using a CAD software package. At that stage, the product geometry is defined and its aesthetic and dimensional characteristics are verified. The main function of digital prototype is to perform 3D CAD modelling. The CAD model is regarded as a central component of the whole system or project information base which means that in all design, analysis and manufacturing activities the same data is utilized. The product and its components are directly designed on a 3D CAD system (e.g.Pro/Engineer, Unigraphics, CATIA, IDEAS, etc.) during the creative design. If a physical part is ready, the model can be constructed by the reverse
engineering technique. RE is a methodology for constructing CAD models of physical parts by digitizing an existing part, creating a digital model and then using it to manufacture components. RE can reduce the development cycle when redesigns become necessary for improved product quality. Preexisting parts with features for improved performance can be readily incorporated into the desired part design. Therefore, it is very useful in creating the CAD model of an existing part when the engineering design is lost or has gone through many design changes. When a designer creates a new design using mock-up, it is also necessary to construct the CAD model of the mock-up for further use of the design data in analysis and manufacturing. The three primary steps in RE process are part digitization, features extraction, and CAD modelling. Part digitization is accomplished by a variety of contact or non-contact digitizers. There are various commercial systems available for part digitization. These systems range from coordinate measuring machine (CMM), laser scanners to ultrasonic digitizers. They can be classified into two broad categories: contact and non-contact. Laser triangulation scanner (LTS), magnetic resonance images (MRI), and computer tomography (CT) are commonly used as non-contact devices. Contact digitizers mainly have CMM and cross-sectional imaging measurement (CIM). Feature extraction is normally achieved by segmenting the digitized data and capturing surface features such as edges. Part modelling is fulfiled through fitting a variety of surfaces to the segmented data points.
In order to reduce the iterations of design-prototype-test cycles, increase the product process and manufacturing reliability, it is necessary to guide in optimizing the product design and manufacturing process through virtual prototype (VP). VP is a process of using 3D CAD model, in lieu of a physical prototype, for testing and evaluation of specific characteristics of a product or a manufacturing process. It is often carried out by CAE and virtual manufacturing system. Computer aided engineering (CAE) analysis is an integral part of time-compression technologies. Various software tools available (i.e. ANSYS, MARC, I-DEAS, AUTOFORM, DYNAFORM, etc.) can speed up the development of new products by initiating design optimization before physical prototypes are built. The CAD models can be transferred to a CAE environment for an analysis of the product functional performance and of the manufacturing processes for producing the product’s components. It has also proven to be of great value in the design optimization of part geometry, to determine its dimensions and to control warpage and shrinkage while
minimizing process-induced residual stresses and deformations. Virtual manufacturing system (VM) is the natural extension of CAE. It simulates the product functionality and the processes for producing it prior to the development of physical prototypes. VM enables a designer to visualize and optimize a product process with a set of process parameters. The visualization of a virtually simulated part prior to physical fabrication helps to reduce unwanted prototype iterations. Therefore, a product virtual manufacturing system may result in accurate determination of the process parameters, and reduce the number of costly physical prototype iterations. 3D CAD model and VP allow most problems with unfitting to become obvious early in the product development process. Assemblies can be verified for interference as VP can be exercised through a range of tasks. Structure and thermal analysis can be performed on the same model employing CAE applications as well as simulating down-stream manufacturing processes. It is clear that VP increases process and product reliability. Although VP is intended to ensure that unsuitable designs are rejected or modified, in many cases, a visual and physical evaluation of the real component is needed. This often requires physical prototype to be produced. Hence, once the VP is finished, the model may often be sent directly to physical fabrication.
The CAD model can be directly converted to the physical prototype using a RP technique or high-speed machining (HSM) process. The 3D CAD model is to be exported not only in the STL format which is considered the de facto standard for interfacing CAD and RP systems, but also in the NC coding which can be used by HSM. HSM has a potential for rapid producing plaster or wooden pattern for RT. RP is a new forming process which fabricates physical parts layer by layer under computer control directly from 3D CAD models in a very short time. In contrast to traditional machining methods, the majority of rapid prototyping systems tend to fabricate parts based on additive manufacturing process, rather than subtraction or removal of material. Therefore, this type of fabrication is unconstrained by the limitations attributed to conventional machining approaches. The application of RP technique as a useful tool can provide benefits throughout the process of developing new products. Specifically, there are serious benefits that RP can bring in the areas of market research, sales support, promotional material, and the ever-important product launch. Physical RP can also become a powerful communications tool to ensure that everyone involved in the
development process fully understands and appreciates the product being developed. Hence, it can help to reduce substantially the inevitable risks in the route from product concept to commercial success, and help shorten time-to-market, improve quality and reduce cost. Over the last 20 years, RP machines have been widely used in industry. The RP methods commercially available include Stereolithgraphy (SLA), Selective Laser Sintering (SLS), Fused Deposition Manufacturing (FDM), Laminated Object Manufacturing (LOM), Ballistic Particle Manufacturing (BMP), and Three-Dimensional Printing (3D printing), etc.
Once the design has been accepted, the realization of the production line represents a major task with a long lead time before any product can be put to the market. In particular, the preparation of complex tooling is usually in the critical path of a project and has therefore a direct and strong influence on time-to-market. In order to reduce the product development time and cost, the new technique of RT has been developed. RT is a technique that can transform the RP patterns into functional parts, especially metal parts. It offers a fast and low cost method to produce moulds and functional parts. Furthermore, the integration of both RP and RT in development strategy promotes the implementation of concurrent engineering in companies. Numerous processes have been developed for producing dies from RP system. The RT methods can generally be divided into direct and indirect tooling categories, and also soft (firm) and hard tooling subgroups. Indirect RT requires some kinds of master patterns, which can be made by conventional methods (e.g. HSM), or more commonly by an RP process such as SLA or SLS. Direct RT, as the name suggests, involves the manufacturing of a tool cavity directly on a RP system, hence eliminating the intermediate step of generating a pattern. Soft tooling can be obtained via replication from a positive pattern or master. Soft tooling is associated with low costs; used for low volume production and uses materials that have low hardness levels such as silicones, epoxies, low melting point alloys, etc. RTV silicone rubber moulds, epoxy moulds, metal spraying moulds, etc. are some of these typical soft moldings. Hard tooling is associated with higher volume of production, and the use of materials of greater hardness. Keltool process, Quickcast process, and the ExpressTool process are some of these hard toolings. Electrical discharge machining (EDM) seems to be an interesting area in which rapid tooling finds a potential application. Some methods of making EDM electrodes based on RP technique have developed, such as abrading process, copper
electroforming and net shape casting, etc. On the basis of the above techniques, a novel integrated system of rapid product development is to be proposed. Its overall architecture is shown in Fig. 1.
3. Case Studies
3.1. Case study 1: Impeller
A total of thirty plastic impellers, with a relatively complex geometry, were required by a customer within fifteen working days from the receipt of a 2D CAD model. There were many factors to be considered in deciding the most appropriate route for producing the impellers. These factors mainly involved cost, lead-time, the number of parts required, the final material for the parts, and the part geometry. In order to maximize the benefits in terms of time and cost reduction for the parts, it was decided to use silicon rubber mould and the parts were eventually produced by vacuum casting process. Silicon rubber mould is an easy, relatively inexpensive and fast way to fabricate prototype or pre-production tools. It can be utilized for moulding parts in wax, polyurethane, ABS, and a few epoxy materials. The process is best suited for projects where form, fit, or functional testing can be done with a material which mimics the characteristics of the production material. The casting parts with fine details and very thin walls can be easily and rapidly produced. The whole process flow involved the 3D CAD modelling, producing master pattern (RP prototype), silicon rubber mould, and casting green parts. The time sequence for the fabrication of impellers was described as follows. Due to the complexity of the impeller, the task of generating the 3D CAD model using Pro/Engineer software package took almost 3 calendar days. The master pattern for this project was built on a SPS 600 machine in 2 calendar days. SL process was chosen because it was cost effective and the surface finish was good. The next step involved creating a roomtemperature vulcanized (RTV) silicone rubber mold which was completed within an additional 3 calendar days. Finally, the ABS materials were cast into silicon rubber mould under the vacuum casting condition, and the green parts were achieved in 4 calendar days. The required 30 components were produced successfully and completed in 12 calendar days. The primary process stages are illustrated in Fig. 2. These impellers only cost about 5 thousand RM
B and took 12 working days. Consequently, in contrast to the traditional development mode, the impellers developed using the integrated system can cut cost by up to 50% and the time-to-market by 75%. When evaluated against satisfying urgent requirement with respect to time, the procedure is clearly worth pursuing, as indicated by the case study described above. Gong from a 3D CAD solid modeling to fully functional production
impellers in less than 12 working days is certainly extraordinary.With proper implementation of the process by qualified personnel, working within the scope of the constraints noted, the acceptance and advancement of the integrated manufacturing method is likely to grow.
3.2. Case study 2: Mannequin
Ten plastic mannequins were required by a client in three months from the receipt of the plaster model of the emulational body. This component was an ideal candidate for using integrated system to development, with a very complex surface and a requirement for only 10 parts. In order to produce the plastic mannequin, the various technologies including reverse engineering, 3D CAD, rapid prototyping and rapid tooling were used to complete model measuring, surfaces reconstructing, 3D CAD modelling, prototype and mould building. The whole development work was presented below. The first step of the project was to construct a CAD model of the emulational body by RE process. ATOS measuring equipment made in GOM Inc. which has a high scanning (10,000 points/sec) and can measure models in a wide range from 500mm to 10mm, was employed to capture the digitized data of the plaster mold. Figure 3(a) shows the point clouds of the body
model. The subsequent process was to perform surfaces reconstructing. To speed this process, a special reverse engineering program, called CopyCAD (Delcam Inc.), was used to create quickly and easily the CAD surfaces from the digitized data. After surfaces reconstructing, many errors in the original model and the joints must be modified by PowerShape software package (another software of Delcam Inc.). The surfaces model of the body is represented in Fig. 3(b). To fabricate easily, the surface model was divided into 11 individual components which included the head, body, upper arms, forearms, tights, shanks and feet using Pro/Engineer software package. Subsequently, every surface model was converted to a solid model, and many holes and slots needed to be designed for fixing joints such as shoulder, knees, etc. Then, the solid parts and joints were assembled to form the solid model of the emulational body. Figure 3(c) illustrates the completed CAD solid model. The RP prototypes of these components were built on a LPS 600 machine. The assembly RP body model is shown in Fig. 3(d). In addition, silicon rubber moulds of these components were fabricated for producing the green parts. Finally, the required 10 plastic mannequins were produced successfully and the project was completed in about 12 weeks. Figures 3(e) and (f) describe respectively the silicon rubber mould of half head and the green product. The case indicates the rapid development of large product and complex surfaces can be realized quickly following the integrated development mode.
4. Conclusion
In this paper, we have presented an integrated system based on RP for rapid product developing. The system consists of four modules: digital prototype, virtual prototype, physical prototype and rapid tooling. It employs fully and integrates closely the various advanced manufacturing technologies which involve the 3D CAD, RE, CAE, RP, and RT. In this system, the procedure of development from design to end product is worked step by step: design, analysis, rapid prototype and tooling. By evaluating the whole process and its various components, and comparing them with traditional process, it has been clear that one can reap benefits in various ways. The system can effectively compress the design and manufacturing cycle time and reduce the development cost, which is an important factor in competition. Using this integrated system to develop new product shows a high potential for faster response to market and customers’ demands. As a result, it will play a more and more important role to reduce the manufacturing cycle and cost of product development in the future.
Acknowledgements
This research was supported by The National High Technology Research and Development Program (863 Program) under the project “The integrated manufacturing technology and equipments of rapid tooling for rapid product development”
(No.2001AA421270), and “Tenth Five-Year” National Key T echnologies R&D Program of China under the project “Research and demonstrator of rapid manufacturing integrated system based on rapid prototyping” (No. 2001BA205B10- CMTT1001).
附录 科技译文： Numerical Control Numerical Control(NC) is a method of controlling the movements of machineComponents by directly inserting coded instructions in the form of numerical data(numbers and data ) into the system.The system automatically interprets these data and converts to output signals. These signals ,in turn control various machine components ,such as turning spindles on and off ,changing tools,moving the work piece or the tools along specific paths,and turning cutting fluits on and off. In order to appreciate the importer of numerical control of machines ,let’s briefly review how a process such as machining has been carried out traditionally .After studying the working drawing of a part, the operator sets up the appropriate process parameters(such as cutting speed ,feed,depth of cut,cutting fluid ,and so on),determines the sequence of operations to be performed,clamps the work piece in a workholding device such as chuck or collet ,and proceeds to make the part .Depending on part shape and the dimensional accuracy specified ,this approach usually requires skilled
外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华
外文资料名称： Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处：Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件： 1.外文资料翻译译文 2.外文原文
应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金，洪城铱昌，宰瑾李， 刘链柱译 摘要：旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率，压降，并切成尺寸被粒度对应于分级收集的50％的效率进行了研究。颗粒切成大小降低入口面积，体直径，减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法，用于收集在家庭中产生的粉尘。 摘要及关键词：吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子，工作场所，或其他建筑，因此，室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物，毒物，食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤，预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中，吸入压力下降说唱空转成比例地清洗的时间，以及纸过滤器也应定期更换，由于压力下降，气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形，在粗颗粒（>2.0微米）模式为主要的外部来源，如风吹尘，海盐喷雾，火山，从工厂直接排放和车辆废气排放，以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式，典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克，可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。
机械设计 摘要：机器是由机械装置和其它组件组成的。它是一种用来转换或传递能量的装置，例如：发动机、涡轮机、车辆、起重机、印刷机、洗衣机、照相机和摄影机等。许多原则和设计方法不但适用于机器的设计，也适用于非机器的设计。术语中的“机械装置设计”的含义要比“机械设计”的含义更为广泛一些，机械装置设计包括机械设计。在分析运动及设计结构时，要把产品外型以及以后的保养也要考虑在机械设计中。在机械工程领域中，以及其它工程领域中，所有这些都需要机械设备，比如：开关、凸轮、阀门、船舶以及搅拌机等。 关键词：设计流程设计规则机械设计 设计流程 设计开始之前就要想到机器的实际性，现存的机器需要在耐用性、效率、重量、速度，或者成本上得到改善。新的机器必需具有以前机器所能执行的功能。 在设计的初始阶段，应该允许设计人员充分发挥创造性，不要受到任何约束。即使产生了许多不切实际的想法，也会在设计的早期，即在绘制图纸之前被改正掉。只有这样，才不致于阻断创新的思路。通常,还要提出几套设计方案，然后加以比较。很有可能在这个计划最后决定中,使用了某些不在计划之内的一些设想。 一般的当外型特点和组件部分的尺寸特点分析得透彻时，就可以全面的设计和分析。接着还要客观的分析机器性能的优越性，以及它的安全、重量、耐用性，并且竞争力的成本也要考虑在分析结果之内。每一个至关重要的部分要优化它的比例和尺寸，同时也要保持与其它组成部分相协调。 也要选择原材料和处理原材料的方法。通过力学原理来分析和实现这些重要的特性，如那些静态反应的能量和摩擦力的最佳利用，像动力惯性、加速动力和能量；包括弹性材料的强度、应力和刚度等材料的物理特性，以及流体润滑和驱动器的流体力学。设计的过程是重复和合作的过程，无论是正式或非正式的进行，对设计者来说每个阶段都很重要。 最后，以图样为设计的标准，并建立将来的模型。如果它的测试是符合事先要
翻译概述（1） 一、学科特点 翻译是一种跨越时空的语言活动，是"把一种语言已经表达出来的东西用另一种语言准确而完整地重新表达出来"(范存忠："漫谈翻译"《翻译理论与技巧》中国对外翻译出版公司，1985，p.80), 是"从语义到文体在译入语中用最切近而又最自然的对等语再现原语的信息"（谭载喜：《奈达论翻译》中国对外翻译出版公司，1984，p.10）。翻译虽为个体所承作，却是一种社会活动，一门综合性很强的学科。它既有很强的理论性又有丰富的实践内涵。就前者而言，翻译经过千百年来各国翻译家的共同努力，已经在语言学、文学、文化、心理学、人类学、哲学和教育学等学科的基础上初步建立了一套理论体系，并在具体实践中总结出了一套行之有效的跨文化和语言转换模式。随着科学的日益进步，这种体系和模式正处在不断地完善之中。就后者而言，翻译是人类社会活动的产物，具有很强的实践性。翻译理论与实践的关系是辨证的；翻译理论产生于翻译实践，反过来又指导实践，实践转过来又丰富翻译理论。可以说，没有社会实践就不会有翻译理论的产生；没有翻译理论作为指导，翻译实践就会难免走弯路。因此，学好翻译既要重视翻译理论的学习，又要加强翻译实践；理论联系实际，这是我们学好翻译的必由之路。 二、为什么可能有翻译 翻译是人类社会发展和进步的需要，因为人类社会要发展进步就需要在不同文化的民族之间进行沟通，而这一全过程都离不开翻译。正如Steiner和张培基所说的那样：Translating it is that openeth the window, to let in the light; that breaketh the shell, that we may eat the kernel. (Steiner) 翻译是沟通各族人民的思想，促进政治、经济、文化、科学、技术交流的重要手段，
附录 INTEGRATION OF MACHINERY （From ELECTRICAL AND MACHINERY INDUSTRY）ABSTRACT Machinery was the modern science and technology development inevitable result, this article has summarized the integration of machinery technology basic outline and the development background .Summarized the domestic and foreign integration of machinery technology present situation, has analyzed the integration of machinery technology trend of development. Key word：integration of machinery ，technology，present situation ，product t，echnique of manufacture ，trend of development 0. Introduction modern science and technology unceasing development, impelled different discipline intersecting enormously with the seepage, has caused the project domain technological revolution and the transformation .In mechanical engineering domain, because the microelectronic technology and the computer technology rapid development and forms to the mechanical industry seepage the integration of machinery, caused the mechanical industry the technical structure, the product organization, the function and the constitution, the production method and the management system has had the huge change, caused the industrial production to enter into “the integration of machinery” by “the machinery electrification” for the characteristic development phase. 1. Integration of machinery outline integration of machinery is refers in the organization new owner function, the power function, in the information processing function and the control function introduces the electronic technology, unifies the system the mechanism and the computerization design and the software which constitutes always to call. The integration of machinery development also has become one to have until now own system new discipline, not only develops along with the science and technology, but also entrusts with the new content .But its basic characteristic may summarize is: The integration of machinery is embarks from the system viewpoint, synthesis community technologies and so on utilization mechanical technology, microelectronic technology, automatic control technology,
使用高级分析法的钢框架创新设计 1．导言 在美国，钢结构设计方法包括允许应力设计法(ASD)，塑性设计法(PD)和荷载阻力系数设计法(LRFD)。在允许应力设计中，应力计算基于一阶弹性分析，而几何非线性影响则隐含在细部设计方程中。在塑性设计中，结构分析中使用的是一阶塑性铰分析。塑性设计使整个结构体系的弹性力重新分配。尽管几何非线性和逐步高产效应并不在塑性设计之中，但它们近似细部设计方程。在荷载和阻力系数设计中，含放大系数的一阶弹性分析或单纯的二阶弹性分析被用于几何非线性分析，而梁柱的极限强度隐藏在互动设计方程。所有三个设计方法需要独立进行检查，包括系数K计算。在下面，对荷载抗力系数设计法的特点进行了简要介绍。 结构系统内的内力及稳定性和它的构件是相关的，但目前美国钢结构协会（AISC）的荷载抗力系数规范把这种分开来处理的。在目前的实际应用中，结构体系和它构件的相互影响反映在有效长度这一因素上。这一点在社会科学研究技术备忘录第五录摘录中有描述。 尽管结构最大内力和构件最大内力是相互依存的（但不一定共存），应当承认，严格考虑这种相互依存关系，很多结构是不实际的。与此同时，众所周知当遇到复杂框架设计中试图在柱设计时自动弥补整个结构的不稳定（例如通过调整柱的有效长度）是很困难的。因此，社会科学研究委员会建议在实际设计中，这两方面应单独考虑单独构件的稳定性和结构的基础及结构整体稳定性。图28.1就是这种方法的间接分析和设计方法。
在目前的美国钢结构协会荷载抗力系数规范中，分析结构体系的方法是一阶弹性分析或二阶弹性分析。在使用一阶弹性分析时，考虑到二阶效果，一阶力矩都是由B1,B2系数放大。在规范中，所有细部都是从结构体系中独立出来，他们通过细部内力曲线和规范给出的那些隐含二阶效应，非弹性，残余应力和挠度的相互作用设计的。理论解答和实验性数据的拟合曲线得到了柱曲线和梁曲线，同时Kanchanalai发现的所谓“精确”塑性区解决方案的拟合曲线确定了梁柱相互作用方程。 为了证明单个细部内力对整个结构体系的影响，使用了有效长度系数，如图28.2所示。有效长度方法为框架结构提供了一个良好的设计。然而，有效长度方法的
中英文资料对照外文翻译 机械设计 摘要： 机器由机械和其他元件组成的用来转换和传输能量的装置。比如：发动机、涡轮机、车、起重机、印刷机、洗衣机和摄影机。许多机械方面设计的原则和方法也同样适用于非机械方面。术语中的“构造设计”的含义比“机械设计”更加广泛，构造设计包括机械设计。在进行运动分析和结构设计时要把产品的维护和外形也考虑在机械设计中。在机械工程领域中，以及其它工程领域，都需要机械设备，比如：开关、凸轮、阀门、船舶以及搅拌机等。 关键词：设计流程设计规则机械设计 设计流程 设计开始之前就要想到机器的实用性，现有的机器需要在耐用性、效率、重量、速度，或者成本上得到改善。新的机器必需能够完全或部分代替以前人的功能，比如计算、装配、维修。 在设计的初级阶段，应该充分发挥设计人员的创意，不要受到任何约束。即使有一些不切实际的想法，也可以在设计的早期，即在绘制图纸之前被改正掉。只有这样，才不致于阻断创新的思路。通常,必须提出几套设计方案,然后进行比较。很有可能在这个计划最后指定使用某些不在计划方案内的一些想法的计划。 一般当产品的外型和组件的尺寸特点已经显现出来的时候，就可以进行全面的设计和分析。接着还要客观的分析机器性能、安全、重量、耐用性，并且成本也要考虑在内。每一个至关重要的部分要优化它的比例和尺寸，同时也要保持与其它组成部分的平衡。 选择原材料和工艺的方法。通过力学原理来分析和实现这些重要的特性，如稳定和反应的能量和摩擦力的利用，动力惯性、加速度、能量；包括材料的弹性强度、应力和刚度等物理特性，以及流体的润滑和驱动器的流体力学。设计的过程是一个反复与合作的过程，无论是正式的还是非正式的，对设计者来说每个阶段都很重要。。产品设计需要大量的研究和提升。许多的想法,必须通过努力去研究成为一种理念,然后去使用或放弃。
本科毕业论文(设计) 外文翻译 学院：机电工程学院 专业：机械工程及自动化 姓名：高峰 指导教师：李延胜 2011年05 月10日 教育部办公厅 Failure Analysis，Dimensional Determination And
Analysis，Applications Of Cams INTRODUCTION It is absolutely essential that a design engineer know how and why parts fail so that reliable machines that require minimum maintenance can be designed．Sometimes a failure can be serious，such as when a tire blows out on an automobile traveling at high speed．On the other hand，a failure may be no more than a nuisance．An example is the loosening of the radiator hose in an automobile cooling system．The consequence of this latter failure is usually the loss of some radiator coolant，a condition that is readily detected and corrected．The type of load a part absorbs is just as significant as the magnitude．Generally speaking，dynamic loads with direction reversals cause greater difficulty than static loads，and therefore，fatigue strength must be considered．Another concern is whether the material is ductile or brittle．For example，brittle materials are considered to be unacceptable where fatigue is involved． Many people mistakingly interpret the word failure to mean the actual breakage of a part．However，a design engineer must consider a broader understanding of what appreciable deformation occurs．A ductile material，however will deform a large amount prior to rupture．Excessive deformation，without fracture，may cause a machine to fail because the deformed part interferes with a moving second part．Therefore，a part fails(even if it has not physically broken)whenever it no longer fulfills its required function．Sometimes failure may be due to abnormal friction or vibration between two mating parts．Failure also may be due to a phenomenon called creep，which is the plastic flow of a material under load at elevated temperatures．In addition，the actual shape of a part may be responsible for failure．For example，stress concentrations due to sudden changes in contour must be taken into account．Evaluation of stress considerations is especially important when there are dynamic loads with direction reversals and the material is not very ductile． In general，the design engineer must consider all possible modes of failure，which include the following． ——Stress ——Deformation ——Wear ——Corrosion ——Vibration ——Environmental damage ——Loosening of fastening devices
机械设计理论 机械设计是一门通过设计新产品或者改进老产品来满足人类需求的应用技术科学。它涉及工程技术的各个领域，主要研究产品的尺寸、形状和详细结构的基本构思，还要研究产品在制造、销售和使用等方面的问题。 进行各种机械设计工作的人员通常被称为设计人员或者机械设计工程师。机械设计是一项创造性的工作。设计工程师不仅在工作上要有创造性，还必须在机械制图、运动学、工程材料、材料力学和机械制造工艺学等方面具有深厚的基础知识。如前所诉，机械设计的目的是生产能够满足人类需求的产品。发明、发现和科技知识本身并不一定能给人类带来好处，只有当它们被应用在产品上才能产生效益。因而，应该认识到在一个特定的产品进行设计之前，必须先确定人们是否需要这种产品。 应当把机械设计看成是机械设计人员运用创造性的才能进行产品设计、系统分析和制定产品的制造工艺学的一个良机。掌握工程基础知识要比熟记一些数据和公式更为重要。仅仅使用数据和公式是不足以在一个好的设计中做出所需的全部决定的。另一方面，应该认真精确的进行所有运算。例如，即使将一个小数点的位置放错，也会使正确的设计变成错误的。 一个好的设计人员应该勇于提出新的想法，而且愿意承担一定的风险，当新的方法不适用时，就使用原来的方法。因此，设计人员必须要有耐心，因为所花费的时间和努力并不能保证带来成功。一个全新的设计，要求屏弃许多陈旧的，为人们所熟知的方法。由于许多人墨守成规，这样做并不是一件容易的事。一位机械设计师应该不断地探索改进现有的产品的方法，在此过程中应该认真选择原有的、经过验证的设计原理，将其与未经过验证的新观念结合起来。 新设计本身会有许多缺陷和未能预料的问题发生，只有当这些缺陷和问题被解决之后，才能体现出新产品的优越性。因此，一个性能优越的产品诞生的同时，也伴随着较高的风险。应该强调的是，如果设计本身不要求采用全新的方法，就没有必要仅仅为了变革的目的而采用新方法。 在设计的初始阶段，应该允许设计人员充分发挥创造性，不受各种约束。即使产生了许多不切实际的想法，也会在设计的早期，即绘制图纸之前被改正掉。只有这样，才不致于堵塞创新的思路。通常，要提出几套设计方案，然后加以比较。很有可能在最后选定的方案中，采用了某些未被接受的方案中的一些想法。
沈阳工业大学工程学院 毕业设计（论文）外文翻译 毕业设计（论文）题目：工具盒盖注塑模具设计 外文题目：Friction , Lubrication of Bearing 译文题目：轴承的摩擦与润滑 系（部）：机械系 专业班级：机械设计制造及其自动化0801 学生姓名：王宝帅 指导教师：魏晓波 2010年10 月15 日
外文文献原文： Friction , Lubrication of Bearing In many of the problem thus far , the student has been asked to disregard or neglect friction . Actually , friction is present to some degree whenever two parts are in contact and move on each other. The term friction refers to the resistance of two or more parts to movement. Friction is harmful or valuable depending upon where it occurs. friction is necessary for fastening devices such as screws and rivets which depend upon friction to hold the fastener and the parts together. Belt drivers, brakes, and tires are additional applications where friction is necessary. The friction of moving parts in a machine is harmful because it reduces the mechanical advantage of the device. The heat produced by friction is lost energy because no work takes place. Also , greater power is required to overcome the increased friction. Heat is destructive in that it causes expansion. Expansion may cause a bearing or sliding surface to fit tighter. If a great enough pressure builds up because made from low temperature materials may melt. There are three types of friction which must be overcome in moving parts: (1)starting, (2)sliding, and(3)rolling. Starting friction is the friction between two solids that tend to resist movement. When two parts are at a state of rest, the surface irregularities of both parts tend to interlock and form a wedging action. To produce motion in these parts, the wedge-shaped peaks and valleys of the stationary surfaces must be made to slide out and over each other. The rougher the two surfaces, the greater is starting friction resulting from their movement . Since there is usually no fixed pattern between the peaks and valleys of two mating parts, the irregularities do not interlock once the parts are in motion but slide over each other. The friction of the two surfaces is known as sliding friction. As shown in figure ,starting friction is always greater than sliding friction . Rolling friction occurs when roller devces are subjected to tremendous stress which cause the parts to change shape or deform. Under these conditions, the material in front of a roller tends to pile up and forces the object to roll slightly uphill. This changing of shape , known as deformation, causes a movement of molecules. As a result ,heat is produced from the added energy required to keep the parts turning and overcome friction. The friction caused by the wedging action of surface irregularities can be overcome
理工学院毕业设计(论文)外文资料翻译 专业：热能与动力工程 姓名：赵海潮 学号：09L0504133 外文出处：Applied Acoustics, 2010(71):701~707 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 基于一维CFD模型下汽车排气消声器的实验研究与预测Takeshi Yasuda, Chaoqun Wua, Noritoshi Nakagawa, Kazuteru Nagamura 摘要目前，利用实验和数值分析法对商用汽车消声器在宽开口喉部加速状态下的排气噪声进行了研究。在加热工况下发动机转速从1000转/分钟加速到6000转/分钟需要30秒。假定其排气消声器的瞬时声学特性符合一维计算流体力学模型。为了验证模拟仿真的结果，我们在符合日本工业标准（JIS D 1616）的消声室内测量了排气消声器的瞬态声学特性，结果发现在二阶发动机转速频率下仿真结果和实验结果非常吻合。但在发动机高阶转速下（从5000到6000转每分钟的四阶转速，从4200到6000转每分钟的六阶转速这样的高转速范围内），计算结果和实验结果出现了较大差异。根据结果分析，差异的产生是由于在模拟仿真中忽略了流动噪声的影响。为了满足市场需求，研究者在一维计算流体力学模型的基础上提出了一个具有可靠准确度的简化模型，相对标准化模型而言该模型能节省超过90％的执行时间。 关键字消声器排气噪声优化设计瞬态声学性能 1 引言 汽车排气消声器广泛用于减小汽车发动机及汽车其他主要部位产生的噪声。一般而言，消声器的设计应该满足以下两个条件：（1）能够衰减高频噪声，这是消声器的最基本要求。排气消声器应该有特定的消声频率范围，尤其是低频率范围，因为我们都知道大部分的噪声被限制在发动机的转动频率和它的前几阶范围内。（2）最小背压，背压代表施加在发动机排气消声器上额外的静压力。最小背压应该保持在最低限度内，因为大的背压会降低容积效率和提高耗油量。对消声器而言，这两个重要的设计要求往往是互相冲突的。对于给定的消声器，利用实验的方法，根据距离尾管500毫米且与尾管轴向成45°处声压等级相近的排气噪声来评估其噪声衰减性能，利用压力传感器可以很容易地检测背压。 近几十年来，在预测排气噪声方面广泛应用的方法有：传递矩阵法、有限元法、边界元法和计算流体力学法。其中最常用的方法是传递矩阵法（也叫四端网络法）。该方
机械设计理论 The machine design theory The machine design is through designs the new product or improves the old product to meet the human need the application technical science. It involves the project technology each domain, mainly studies the product the size, the shape and the detailed structure basic idea, but also must study the product the personnel which in aspect the and so on manufacture, sale and use question. Carries on each kind of machine design work to be usually called designs the personnel or machine design engineer. The machine design is a creative work. Project engineer not only must have the creativity in the work, but also must in aspect and so on mechanical drawing, kinematics, engineerig material, materials mechanics and machine manufacture technology has the deep elementary knowledge. If front sues, the machine design goal is the production can meet the human need the product. The invention, the discovery and technical knowledge itself certainly not necessarily can bring the advantage to the humanity, only has when they are applied can produce on the product the benefit. Thus, should realize to carries on before the design in a specific product, must first determine whether the people do need this kind of product Must regard as the machine design is the machine design personnel carries on using creative ability the product design, the system analysis and a formulation product manufacture technology good opportunity. Grasps the project elementary knowledge to have to memorize some data and the formula is more important than. The merely service data and the formula is insufficient to the completely decision which makes in a good design needs. On the other hand, should be earnest precisely carries on all operations. For example, even if places wrong a decimal point position, also can cause the correct design to turn wrongly.
《翻译》课程理论汇编（基本概念） 1.1 翻译的概念 一般地，我们将翻译定义为：将一种语言（口语或笔语形式）（译出语）转换或创造为另一种语言（译入语）。翻译是一种非常复杂的 人类高级语言活动，这种活动的整个过程是很难以图示、语言等其他方式阐释清楚的。不同领域、不同派别的学者对翻译有着不同的定义。 1.1.1 语言学家对翻译的定义 语言学家将翻译视为一种语言活动，同时认为，翻译理论属于语言学的一个部分，即研究译出语和译入语的转换关系。解释如下： （1）Catford（1965：20）认为，翻译是译出语和译入语间的文本等效转换。 （2）Nida 和Taber（1969：12）认为，翻译是译出语和译入语间意义和形式上的最紧密联系转换。 （3）Newmark（1982/1988：5）认为，翻译理论源自于比较语言学，属于语义学的一部分，而所有语义学的研究课题都与翻译理论息 息相关。 1.1.2 文化角度对翻译的定义 从文化角度来看，翻译不仅仅是语言符号的转换，同时是文化的交流，尤其是“文化间交流”。通常我们把这一术语又改称为“文化 间合作”或“跨文化交际”等。 Shuttleworth 和Cowie（1997：35）认为，与其说翻译是两种语言之间的符号转换，不如说是两种语言所代表的两种文化间的转换。 译者在处理涉及语言文化方面的译务工作时，认为任何一种语言中都饱含着其文化中的相关元素（比如：语言中的问候语、固定搭配 等），任何文本都存在于特定的文化环境中，同时，由于各语言所代表的多元文化差异很大，语言间的转化和创造性生成模式千变万化。 Nida 认为，对于一个成功的翻译工作者而言，掌握两种文化比掌握两种语言更为重要，因为语言中的词汇只有在特定的语言文化环境 中才能具有正确的、合乎文化背景的义项。 王佐良先生指出（1989），翻译不仅涉及语言问题，也涉及文化问题。译者不仅要了解外国的文化，还要深入了解自己民族的文化。 不仅如此，还要不断的将两种文化加以比较，因为真正的对等应该是在各自文化中的含义、作用、范围、感情色彩、影响等等都是相当的。 翻译者必须是一个真正意义的文化人。人们会说：他必须掌握两种语言；确实如此，但是不了解语言当中的文化，谁也无法真正掌握语言。 1.1.3 文学角度对翻译的定义 持文学观点的翻译工作者认为，翻译是对语言的艺术性创造，或是一种善于创造的艺术。一些西方学者也认为，翻译是对“原文本的 艺术性改写”。 文学翻译的任务时要把原作中包含的一定社会生活的映像完好无损地从一种语言移注到另一种语言中，在翻译过程中追求语言的艺术 美，再现原作的艺术性。用矛盾的话说，是“使读者在读译文的时候能够像读原著一样得到启发、感动和美的感受。” 语言是塑造文学形象的工具，因而文学的形象性特征必然要在语言上表现出来。文学语言的特征，诸如形象、生动、鲜明、含蓄、凝
外文资料翻译 学生姓名： 专业班级：机械设计制造及其自动化04级2班指导教师： 2008年6月
装载机发展概况 Abstract This paper have discussed s.s. ZL-50 type fork-lift truck mainly overall fictitious prototype design as well as some kinds of typical schoolwork operating modes imitate and emulate , include equipment and the overall parts needed build mould. In this design course, have applied ADAMS software and the software of PRO/ENGINEER. ADAMS software is used in the emulation of some kinds of schoolwork operating modes, and the software of PRO/ENGINEER is used to build mould mainly. Through the simulated emulation for some kinds of overall schoolwork operating modes, can see relatively distinctly the overall possible condition in actual schoolwork course that met , can in time modify , have reduced actual design time , have raised production efficiency. The innovation of this design Zhi is in in, imitate and have emulated fork-lift truck the 3 kinds of typical schoolwork operating mode in actual schoolwork, is effect again have imitated in actual schoolwork the hydraulic impact of use, so when being helpful to solve actual loading, the actual problem of meeting the stock that is hard to uninstall can so raise production efficiency. Key words: Fork-lift truck 、fictitious prototype , build mould, emulation, optimization、production efficiency Loader Development China's modern 20 wheel loaders began in the mid-1960s of the Z435. The aircraft as a whole rack, rear axle steering. After years of hard work, the attraction was the world's most advanced technology wheel loader on the basis of the successful development of the power of 162 KW of shovel-fit wheel loaders, stereotypes for Z450 (later ZL50), and in 1971 December 18, formally appraised by experts. Thus the birth of China's first articulated wheel loader, thus creating our industry loader formation and development history. Z450-type loader with hydraulic mechanical transmission, power shift, Shuangqiaoshan drive, hydraulic manipulation, articulated power steering, gas oil Afterburner brake wheel loaders, and other modern, the basic structure of the world's advanced level for the time . Basically represent the first generation of wheeled loading the basic structure. The aircraft in the overall performance of dynamic, and insertion force a rise of power and flexibility, manipulation of light, the higher operating efficiency of a series of advantages. 1978, Heavenly Creations by the Department in accordance with the requirements of machinery, worked out to LIUGONG Z450-based type of wheel loaders series of standards. The development of standards, with reservations Z