Development status and application summary of comp

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Summary of the development and application of Computer Aided Engineering (CAE)

Abstract: This paper introduces the main development stages and technical characteristics of computer aided engineering technology, especially the technical characteristics and engineering applications of ANSYS software

key words: computer aided engineering; ANSYS; Engineering analysis

the vitality of engineering and manufacturing lies in the innovation of products. The innovation of modern products is the innovative design based on knowledge and information [1]. In the process of product design, constantly acquiring new knowledge and information, using advanced and reliable design software is the main means of modern product design. Computer aided engineering technology and its software are important tools of modern design, which can analyze the static, dynamic and dynamic characteristics of products in the product design stage Dynamic characteristics, simulate the working state and operation behavior of the product in the future working environment, find and modify the defects in the design at the design stage, and verify the feasibility and reliability of future engineering and product performance [2]

Computer Aided Engineering (CAE) technology is a new technology formed by the combination of computer technology and engineering analysis technology. CAE software is a comprehensive and knowledge intensive information product formed by the combination of computational mechanics, computational mathematics, structural dynamics, digital simulation technology, engineering management and computer technology. The core technology of CAE is finite element theory and numerical calculation method. After decades of development, the object of CAE software analysis has gradually developed from linear system to nonlinear system, from single physical field to multi field coupling system, and has been successfully applied in aviation, aerospace, machinery, architecture, civil engineering, blasting and other fields. With the development of computer technology, CAD technology, CAPP technology, CAM technology, PDM technology and ERP technology, CAE technology gradually infiltrates with them and develops towards the integration of various information technologies

1 computer aided engineering

Computer Aided Engineering (CAE) is a very broad concept. Literally speaking, it can include all aspects of engineering and manufacturing informatization, but the traditional CAE mainly refers to the analysis of the operation performance, safety and reliability of engineering and products with computers, the simulation of their future state and operation state, and the early detection of defects in design and calculation, And confirm the availability and reliability of future engineering and product functions and performance. To be exact, CAE refers to the analysis, calculation and analysis simulation in engineering design, including engineering numerical analysis, structural and process optimization design, strength and life evaluation, and motion/dynamics simulation. Engineering numerical analysis is used to analyze and determine the performance of products; Structure and process optimization design is used to optimize the performance of products and processes on the basis of ensuring product functions and processes; Structural strength and life evaluation is used to evaluate whether the precision design of products is feasible, how reliable and how long the service life is; Motion/dynamics simulation is used to simulate the kinematics and dynamics of the virtual prototype built by CAD. From the perspective of process and practical technology development, the core technology of CAE is finite element technology and motion/dynamics simulation technology of virtual prototype

further analysis of CAE, its specific meaning is shown in the following aspects: (1) use the finite element technology in engineering numerical analysis to analyze and calculate the physical field quantities such as stress and deformation of the product structure, give the distribution of the whole physical field quantities in space and time, and realize the calculation and analysis of the structure from linear and static calculation and analysis to nonlinear and dynamic calculation and analysis; (2) The process optimization design method is used to optimize the product structure, process parameters and structural shape parameters under the constraints of process and design, so as to optimize the product structure performance and process; (3) Using the theory, method and specification of structural strength and life evaluation, the safety, reliability and service life of the structure are evaluated and estimated; (4) Using the theory and method of motion/dynamics, the motion/dynamics simulation of the mechanism and the whole machine designed by CAD solid modeling is carried out, and the motion trajectory, speed, acceleration and dynamic reaction force of the mechanism and the whole machine are given

2 the development status and trend of CAE technology [3]

the theoretical basis of CAE originated in the 1940s. Since mathematician Courant first tried to solve the nano torsion problem with the minimum potential energy principle of piecewise continuous function defined on the triangular region in 943, some applied mathematicians, physicists and engineers also got involved in the concept of finite element for various reasons, Until 1 will cause: because the average temperature is too high or the water temperature is too high in the work for a long time, 960 years later, with the wide application and development of electronic computers, finite element technology has developed rapidly relying on numerical calculation methods. Since 1963-1964, besseling, Melosh and Jones have proved that the finite element method is another form of Ritz method based on the variational principle, which makes all the theoretical basis of Ritz analysis applicable to the finite element method, and confirms that the finite element method is a general method for dealing with continuous media problems. Based on this theory, the application of finite element method has been extended from plane problems of elasticity to space problems, plate and shell problems, and from static equilibrium problems to stability problems, dynamic problems and wave problems; The object of analysis extends from elastic materials to plastic, viscoplastic and composite materials, and from solid mechanics to continuum mechanics such as fluid mechanics and heat transfer. The finite element analysis technology is gradually extended from traditional analysis and verification to optimization design, and closely combined with computer-aided design and manufacturing, forming the current framework of CAE technology

2.1 development of finite element technology after more than 60 years of development, finite element technology has become mature and widely accepted by the engineering community. The corresponding finite element analysis software is developed. These software have reached a relatively high level in function, performance and use. In terms of function, the preprocessor that affects the software can call the geometric model in CAD, conveniently realize lattice division and automatic division, flexibly impose various convenient conditions, define material properties, set different calculation conditions, and realize the call of user subroutines for special problems; The solver has a solution algorithm suitable for different problems (linear equations, nonlinear equations, eigenvalues, etc.); The post processor can give the required visual technical results (isoline, isosurface, cloud map, animation, etc.). In terms of performance, it can solve linear and nonlinear problems, static and dynamic problems, multi materials, various boundary conditions, and engineering like problems (mechanical, electromagnetic, civil, etc.)

2.2 development of structural optimization technology in the early stage of structural optimization methods, intuitive criterion methods were used, such as full stress criterion method, full strain criterion method, etc. In the 1960s, mathematical programming method was introduced into structural optimization design, marking the beginning of modern optimization design. The complex method, feasible direction method and penalty function method in mathematical programming method have been widely used in structural optimization design. The optimization criterion method appeared in the 1970s. Its idea is to combine the mechanical properties of design problems with various approximate means in numerical methods, transform highly nonlinear problems into a series of approximate problems with explicit constraints, and then solve them with the help of mathematical programming. Since the 1980s, structural optimization design has been applied to engineering optimization design, and a specially developed engineering optimization design software has been formed. With the development of computer technology, the scale of engineering optimization design software continues to expand, from the initial dozen variables to tens of thousands of variables, from the initial structural size parameter optimization to today's structural shape optimization. At present, there are more than ten kinds of software with structure optimization function; For example, special structural optimization design software sapop, Astros, oasis, etc., including DDDU with independent copyright in China; Among the finite element analysis software, the software with optimization design function includes ANSYS, strand, etc., and the optimization design software sualnastran integrated with CAD

2.3 development of structural strength and life assessment due to the continuous improvement of the speed, economy, durability and reliability of the structure, as well as the continuous reduction of the weight of the structure, structural strength and life assessment has become more and more complex and important. When selecting complex mechanical and electrical products, we should understand not only the strength index of the equipment, but also the service life index of the equipment. The manufacturer must answer the user under what conditions and how many years the equipment provided by the manufacturer can work reliably. The evaluation of structural strength and life needs the help of relevant theories, methods, industrial specifications and material data. Most of these theories, methods and data are summarized through a large number of experiments and engineering practice. Foreign countries compile the scientific research achievements in this field into software. Such as the failure and damage analysis module in uigue software and RC software. Due to the different national conditions of our country, especially the different contents of the evaluation database, we need to have an evaluation system suitable for our national conditions/our country has also made some progress in the theory, method, specification and database of structural strength and life evaluation, but there is still a big gap. At present, there is no mature software for use, but the content of structural strength and life evaluation in CAE system is essential

2.4 the development of dynamic simulation of engineering structure has formed the dynamic simulation of engineering structure on the basis of CAD modeling design. In this regard, the software launched include Adams and workingmodel, which are general mechanical structure simulation software. Adams provides a simulation environment for simulating the motion and dynamic process of the actual system, which can comprehensively simulate the structure, information and manufacturing process in the actual manufacturing activities. The software includes more than a dozen analysis modules, and its main functions include dynamic simulation and dynamic analysis. Dynamic simulation includes velocity, acceleration, force response, efficiency energy, etc. dynamic analysis includes dynamic signal processing, spectrum analysis, digital filtering, transfer function acquisition, etc

3 development status and trend of CAE software [4 ~ 7]

from 1960 to 1970, the theory of finite element was in the development stage, and the objects of analysis were mainly the strength, stiffness, modal experiment and analysis of aerospace equipment structure. At that time, CAE software was in the exploration period because of the characteristics of less hardware memory, small disk space, slow calculation speed and so on. MSc was founded by Dr. Richard MacNeal and Mr. Robert schwendle in 1963 and developed the first structural analysis software. In 1965, he participated in the research of computer structure analysis method initiated by NASA, and its program industry was renamed msc/nastran. SDRC was established with the support of NASA in 1967, and released the world's first dynamic testing and modal analysis software package in 1968. In 1971, it launched the commercial finite element analysis software supertab (later incorporated into I-DEAS). In 1970, Dr. John A. Swanson founded Swanson analysis system, Inc. (Sasi), which was later reorganized and renamed as ANSYS company to develop ANSYS software. So far, the three major companies in the world have successively set up work to devote themselves to the research and development of large-scale commercial CAE software. Up to now, the pattern of CAE market dominated by these three giants has basically remained. Just in the direction of development, MSC and ANSYS are more focused on the nonlinear analysis market, while SDRC is more inclined to the linear analysis market. At the same time, SDRC has developed its own cad/cae

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