机械设计毕业论文外文翻译

INTRODUCTION The rapid development of science and technology, product features requirements of the growing number and complexity of the increase in life expectancy shortened, replacement faster. However, the design of the products, especially mechanical products in the design means, is力不从心, failed to keep pace with the needs of the times. At present, computer-aided product design drawings, design, manufacturing, production planning has been a relatively extensive and in-depth study and achieved initial results, and product development programmes of the early computer-aided design is far from meeting a need. To this end, the author read a lot of literature on the basis of a summary of the design and scholars at home and abroad to design the method used, and discussed the various methods of organic link between product design and mechanical Computer trend of development. Under the current domestic and foreign scholars to design machinery design methods used by the main features of the programme can be summed up modern design for the following four major types. 1, systematic design method Systematic design of the main features are: design as from a number of design elements of a system, every design element of independence, there are various elements of the organic links and a level of all the design elements Combined, you can design systems to achieve the task. Systematic design idea in the 1970s by the German scholar Professor Pahl and Beitz, a system based on the theory, developed a design of the general pattern, and advocate of the design work should be rational. German Engineers Association in this on the basis of design, develop standards VDI2221 "technology systems and product development design methods. The development of the product design process of mechanical model, basically follow the German standards VDI2221 the design. In addition, many of our product design and scholars in the programme design and also learn from other developed countries cited the systematic design, which is representative: (1) The user needs as the product concept of functional characteristics, structural design and part design, process planning, operations control, and so on the basis of the product development process of the macro, the use of Quality Function layout methods, systems and information needs of users will be reasonable and effective And converted to the various stages of product development objectives and operations control technology means a point of order. (2) products as organisms on the level of life, and life systems through the use of the product design process can demand level of success and realize the concept of functional requirements of the specific levels and product design level. At the same time using the system icons to life the abstract expression of the functional requirements of products, product features a system structure. (3) the mechanical design system in the application of science into two basic questions: First, to design products as a system to process, to determine the best of its components (modules) and their mutual relations and the other is the product design Process as a system, according to the design objectives, correct and reasonable to determine the design of all aspects of the work and the various design stage. As each designer to study issues and to consider the perspective of the different emphases, to design a programme of specific research methods also differ. Here are some representative of the systematic design design elements of With five design elements (functions, effects, effects of vector, shape and surface elements parameters) described "product solution" that a product design elements of the five identified, all the characteristics of products and value characteristics already identified. Chinese scholars have also adopted similar design methods described product of the original understanding. graphical modeling law Development of the design analysis and guidance systems "KALEIT, with a clear level of the graphic description of the product structure and functions related to the abstract information, and the system structure and function of the graphical modeling, and the function of the connection between. Will be assisted design divided into two methods and information exchange, the use of Nijssen information analysis methods can be used graphic symbols, with a variety of semantic model structure, the integration can be described conditions can be divided into binding type, can relations between any combination of features , Will design solutions and information technology integration, the design process to achieve a different level of abstraction of information between the graphical modeling. The literature [11] semantic network design as a design tool in the development of the semantic network design ASK, using nodes and a network of lines describing the design, components of the node that the unit design tasks, functions, components or processing Equipment, etc.), and lines used to adjust the definition node between different semantic relations, which in the design process for all the activities and results of pre-built model, the early design requirements to the definition of a specific structure can be described by the relationship between The definition of the expression, and a computer-aided design process from abstract to concrete leap. "idea" - "design" law Will be divided into product design "concept" and "design" in two stages. "Idea" phase of the mission is to seek, select and design portfolio to meet the requirements of the original understanding of tasks. "Design" stage of work is the concrete realization of the original understanding of the conceptual stage. The programme will be "ideas" for the specific description: According to a suitable functional structure, designed to meet the requirements of the mandate of the original understanding. Functional structure of the sub-function by "structural elements" to achieve, and "structural elements" of the physical connection between the definition of "functional carrier", "functional carrier" and "structural elements" and formation of the interaction between the functional diagram ( Mechanical movement diagram). Programme of "design" is based on functional diagram, the first qualitative description of all the "functional carrier" and "structural elements", then all the quantitative description of "structural elements" and connecting pieces ( "functional vector") the shape and location have The structure of. Roper, H. use of graph theory theory, the help from his definition of "total design unit (GE)", "structure elements (KE)", "functional structure elements (FKE)", "connecting structure elements (VKE)", "Structural parts (KT)", "structural elements parts (KET)" concept, and describes elements of size, location and transmission parameters of the relationship between the number of thumbs, the design intuitive design experts design "stage. From the design methodology of the point of view, the design task will be clear after the design work is divided into three steps: 1) access to functions and functional structure (referred to as "functional"), 2) find effects (referred to as the "effect"); ) To find structure (referred to as "the configuration of the Rules"). And use the following four strategies described machinery idea stage of the process: Strategy 1: were considered "functional" and "effect" and "configuration rules." Therefore, we can work in various steps to create variations in the respective programmes, resulting in the original understanding of the broad spectrum. Strategy 2: "effect" and "configuration rules" (including the designer to create the rules) association, to consider a separate function (usually associated with the design task). At this point, to identify the typical configuration rules and their effects need to have a wealth of experience, the programme spectrum far less than a strategy of the programme spectrum. Strategy 3: "functional" and "effect", "configuration rules" are closely related. Applicable to the function, and the configuration of the rules of no choice, with special requirements of the areas, such as ultra-small machinery, large machinery, high-value function parts, and those with special requirements of the functional components, and so on. Strategy 4: In view of the structural design requirements of the solution. The strategy starting from the existing parts, through different parts of the order and connection, was expected to function. Matrix Design In the programme design process used in "requirement - to" logic tree ( "or" tree) described requirements, the relationship between the function, to satisfy the requirements of functional design solution set, a different design. According to "request - to" logic tree establishment of a "request - to" association matrix, meet the requirements necessary to describe the complex relationship between function, expressed functional requirements and the relationship between the will matrix as a mechanical system design basis, the mechanical system design space as a functional decomposition of space, only that each sub-space design of a module, in the abstract phase of the high-level, with each module design movement conversion matrix And a vector for the operation of restraint that in the abstract phase of the low-rise, each module design parameters were expressed as a matrix and the equation of motion. bond graph Law Will form a system components into the function to generate energy, energy consumption, changing energy forms, such as various types of energy transmission and use of bond graph of the function of the components that will be based on the functions of the model and bonding with plans to achieve functional The automatic generation of structural and functional structure and bonding between the automatic conversion plans to seek bond graph generated by a number of design methods. 2, modular design structure From the perspective of planning products: the definition of its mandate to design features of the product structure is based on the use of existing products (such as GM parts components, etc.) described the design task, that is, when the mandate of decomposition on each task to consider whether there is the corresponding Solutions products, so that in the planning stages of product design tasks to eliminate the contradictions that might exist in the early forecast production capacity, costs and the development of the process of designing the plan adjustable, which can improve the design efficiency and design of reliability, At the same time also reduce the cost of new products. Feldmann will describe the function of the design task is divided into four levels of product structure, (1) products → (2) functional components → (3) main function components → (4) functional components. And the use of application-oriented features of the directory structure, a more specific functional components of the qualitative and quantitative description. At the same time developed for early in the product development and design tools used by early STRAT. Machinery specialized for most of that function can be used existing product solutions and new solutions with only a small number of special features, therefore, for the use of mechanical design features of the product structure, machinery specialized for the evaluation of the design, manufacture risk is very beneficial. Functional Analysis of the products promoted on the basis of the product is broken down into a function of one or more of the basic modular structure, through the selection and combination of these modular structure formed into various products. These basic structure can be parts, components, or even a system. The ideal modular structure should be standardized interface (connectivity and with the Department of), and is serialized, universal, integrated, hierarchical, flexible, economic, with interchangeable, compatibility and relevance of the . China's combination of software component technology and CAD technology, design and composition of deformation design combined, according to grade modular theory, machine processing center will be divided into Youdadaoxiao product level, component level, component-level and component level, and use CAD technology and expertise to their portfolio into different species, different specifications of the functional module, the module from the combination of these functions into different processing center overall programme. To select a design for the directory structure of the variation machinery tools, the design of the proposed elements for a complete, structured format, a solution set design directory. And Set Design listed in the directory comment on each of the additional information, very beneficial to design engineers choice of the elements. According to the connectivity features of mechanical parts and components, will be summarized into four types: 1) The components of direct targeting, and self-adjustment of parts, 2) a common structure of the assembly, 3) have nested structure and inlay Shell-like components of the connection, 4) a modular architecture and modular components of the connection. And a quasi-symbols that the typical components and rules of the connection between the components, to achieve this connection between the components of the algorithm and the concept of visualization. In the mechanical system design, "features a" module on the functions of decomposition, and provides the best functional decomposition "tablets" of the extent of the functional and institutional forms of one-to-one. "Structure to establish" as a function of the module is the choice of targets in order to achieve mapping , based on knowledge of product design features Knowledge-based product design features of the main features are: to use the computer to identify the language describing the characteristics of the product design experts in the field of knowledge and experience to establish the appropriate knowledge base and reasoning machine, and then use the storage areas have been established by the knowledge and reasoning Mechanisms to achieve computer-aided design products. The mechanical system design is based on products with the characteristics, and design experts in the field of knowledge and experience to push volume and decision-making, the completion of several comprehensive. To achieve this stage of the computer-aided design, we must study the automatic acquisition of knowledge, expression, integration, coordination, management and use. To this end, the scholars at home and abroad designed for mechanical systems design knowledge of automated processing done a lot of research work, the method used can be summarized in the following few. coding method According to "campaign conversion" feature (the function million) institutions will be classified, described and use the code function yuan and institutional categories, which established a "body system design expert system" Knowledge Base. On this basis, will be the dual logic and fuzzy comprehensive evaluation of combining theory, the establishment of the "expert systems" reasoning mechanism, and for the four-position for the design of the machine. Use of biological evolution theory, through natural selection and sexual reproduction to the principle of evolution of organisms to the body design, use of network theory methods to express the structure for topology, and then through the coding technology, the structure and institutions Performance of individual chromosomes into the binary string, and in accordance with design requirements of fitness, the use of biological evolution theory of reproduction control mechanism, through the selection, crossover, such as a sudden variation means to eliminate low value of the individual are not suited to the fast evolution Be the best adaptation of the individual, that is, most with the design requirements of the agency programme. knowledge of the law mixed The complex mechanical systems design, mixed use of the knowledge expression describes the design of various types of knowledge is particularly suited to this point has been the design of many scholars of the consensus. In the development of complex product design intelligent decision support system DMDSS, will be the rules, framework, processes and neural networks, and other knowledge that organic combination of methods to adapt to different types of knowledge in the design of the description. Knowledge will be a single expression of a variety of methods (rules, framework and process), according to object-oriented programming principles, the framework of the groove with that object's properties, with rules that target the dynamic characteristics, with the knowledge that the treatment process, group Into a hybrid form of knowledge, and successfully developed the "object-oriented NC gantry milling machine gearbox design intelligent system GBCDIS" and "transmission structure design expert system GBSDES". use of the knowledge-based development tool Coupling in the CAD system, the use of the knowledge-based development tools NEXPERT-OBJECT, through the use of object-oriented approach, to create an object-oriented database design method for coupling the designer to design and structural design Provided extensive and reliable method of the design spectrum. NEXPERT describe the use of linear guide the design of the need to design based on knowledge of the content, which seek to knowledge-based solutions, and developed a linear guide design expert system. Design Law Directory Construction of the "modules", "functional element solution" and "institutions" three progressive design directory, and this directory of three progressive design principles of the programme as a mechanical transmission system intelligent design and development of the knowledge base of design Aids. Based on the example of the way In the development of expert systems design knowledge base, using the basic predicate described design requirements, design conditions and the selected programme, described by frame "Project" and various "concept entity," through case-based reasoning of the technologies used to produce candidate With the horsepower to product design requirements. 4, Intelligent Design Intelligent Design is the main characteristics: According to the theories of design, through the use of 3D graphics software, intelligent design software and virtual reality technology, and multimedia, hypermedia tools for product development design, the concept of products, description of the product结构.

机械 ----------------------- 华文版本 Mechanics is the branch of physics concerned with the behaviour of physical bodies when subjected to forces or displacements, and the subsequent effect of the bodies on their environment. The discipline has its roots in several ancient civilizations. During the early modern period, scientists such as Galileo, Kepler, and especially Newton, laid the foundation for what is now known as Classical mechanics. Significance Mechanics is the original discipline of physics, dealing with the macroscopic world that humans perceive. It is therefore a huge body of knowledge about the natural world. Mechanics encompasses the movement of all matter in the universe under the four fundamental interactions (or forces): gravity, the strong and weak interactions, and the electromagnetic interaction. Mechanics also constitutes a central part of technology, the application of physical knowledge for humanly defined purposes. In this connection, the discipline is often known as engineering or applied mechanics. In this sense, mechanics is used to design and analyze the behavior of structures, mechanisms, and machines. Important aspects of the fields of mechanical engineering, aerospace engineering, civil engineering, structural engineering, materials engineering, biomedical engineering and biomechanics were spawned from the study of mechanics. Classical versus quantum The major division of the mechanics discipline separates classical mechanics from quantum mechanics. Historically, classical mechanics came first, while quantum mechanics is a comparatively recent invention. Classical mechanics originated with Isaac Newton's Laws of motion in Principia Mathematica, while quantum mechanics didn't appear until 1900. Both are commonly held to constitute the most certain knowledge that exists about physical nature. Classical mechanics has especially often been viewed as a model for other so-called exact sciences. Essential in this respect is the relentless use of mathematics in theories, as well as the decisive role played by experiment in generating and testing them. Quantum mechanics is of a wider scope, as it encompasses classical mechanics as a sub-discipline which applies under certain restricted circumstances. According to the correspondence principle, there is no contradiction or conflict between the two subjects, each simply pertains to specific situations. Quantum mechanics has superseded classical mechanics at foundational level and is indispensable for the explanation and prediction of processes at molecular and (sub)atomic level. However, for macroscopical processes classical mechanics is able to solve problems which are unmanageably difficult in quantum mechanics and hence remains useful and well used. Einsteinian versus Newtonian Analogous to the quantum versus classical reformation, Einstein's general and special theories of relativity have expanded the scope of mechanics beyond the mechanics of Newton and Galileo, and made small corrections to them. Relativistic corrections were also needed for quantum mechanics, although relativity is categorized as a classical theory. There are no contradictions or conflicts between the two, so long as the specific circumstances are carefully kept in mind. Just as one could, in the loosest possible sense, characterize classical mechanics as dealing with "large" bodies (such as engine parts), and quantum mechanics with "small" ones (such as particles), it could be said that relativistic mechanics deals with "fast" bodies, and non-relativistic mechanics with "slow" ones. However, "fast" and "slow" are subjective concepts, depending on the state of motion of the observer. This means that all mechanics, whether classical or quantum, potentially needs to be described relativistically. On the other hand, as an observer, one may frequently arrange the situation in such a way that this is not really required. Types of mechanical bodies Thus the often-used term body needs to stand for a wide assortment of objects, including particles, projectiles, spacecraft, stars, parts of machinery, parts of solids, parts of fluids (gases and liquids), etc. Other distinctions between the various sub-disciplines of mechanics, concern the nature of the bodies being described. Particles are bodies with little (known) internal structure, treated as mathematical points in classical mechanics. Rigid bodies have size and shape, but retain a simplicity close to that of the particle, adding just a few so-called degrees of freedom, such as orientation in space. Otherwise, bodies may be semi-rigid, . elastic, or non-rigid, . fluid. These subjects have both classical and quantum divisions of study. For instance: The motion of a spacecraft, regarding its orbit and attitude (rotation), is described by the relativistic theory of classical mechanics. While analogous motions of an atomic nucleus are described by quantum mechanics. Sub-disciplines in mechanics The following are two lists of various subjects that are studied in mechanics. Note that there is also the "theory of fields" which constitutes a separate discipline in physics, formally treated as distinct from mechanics, whether classical fields or quantum fields. But in actual practice, subjects belonging to mechanics and fields are closely interwoven. Thus, for instance, forces that act on particles are frequently derived from fields (electromagnetic or gravitational), and particles generate fields by acting as sources. In fact, in quantum mechanics, particles themselves are fields, as described theoretically by the wave function. Classical mechanics The following are described as forming Classical mechanics: Newtonian mechanics, the original theory of motion (kinematics) and forces (dynamics) Lagrangian mechanics, a theoretical formalism Hamiltonian mechanics, another theoretical formalism Celestial mechanics, the motion of stars, galaxies, etc. Astrodynamics, spacecraft navigation, etc. Solid mechanics, elasticity, the properties of (semi-)rigid bodies Acoustics, sound in solids, fluids, etc. Statics, semi-rigid bodies in mechanical equilibrium Fluid mechanics, the motion of fluids Soil mechanics, mechanical behavior of soils Continuum mechanics, mechanics of continua (both solid and fluid) Hydraulics, fluids in equilibrium Applied / Engineering mechanics Biomechanics, solids, fluids, etc. in biology Statistical mechanics, large assemblies of particles Relativistic or Einsteinian mechanics, universal gravitation Quantum mechanics The following are categorized as being part of Quantum mechanics: Particle physics, the motion, structure, and reactions of particles Nuclear physics, the motion, structure, and reactions of nuclei Condensed matter physics, quantum gases, solids, liquids, etc. Quantum statistical mechanics, large assemblies of particles Professional organizations Applied Mechanics Division, American Society of Mechanical Engineers Fluid Dynamics Division, American Physical Society

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