摘要：A method for optimizing automotive doors under multiple criteria involving the side impact, stiffness, natural frequency, and structure weight is presented. Metamodeling technique is employed to construct approximations to replace the high computational simulation models. The approximating functions for stiffness and natural frequency are constructed using Taylor series approximation. Three popular approximation techniques,*** response surface (PRS), stepwise regression (SR), and Kriging are studied on their accuracy in the construction of side impact functions. Uniform design is employed to sample the design space of the door impact analysis. The optimization problem is solved by a multi-objective genetic algorithm. It is found that SR technique is superior to PRS and Kriging techniques in terms of accuracy in this study. The numerical results demonstrate that the method successfully generates a well-spread Pareto optimal set. From this Pareto optimal set, decision makers can select the most suitable design according to the vehicle program and its application.

摘要：For a single cylinder engine, the total unbalanced inertial forces occur in the engine block, which results in engine’s vibration and deteriorated noise. In order to eliminate the unbalanced forces, counterweight and primary balance shaft should be attached to the cylinder block so that engine durability and ride comfortability may be further improved. Traditionally one third of connecting rod assembly’s mass is treated as reciprocating mass, and two thirds as rotating mass when designing balance mechanism. In this paper, a new method based on the multibody dynamics simulation is introduced to separate the reciprocating mass and rotating mass of connecting rod assembly. The model consists of crankshaft, connecting rod, piston and the simulation is performed subsequently. According to the simulation results of the main bearing loads, the reciprocating mass and rotating mass are separated. Finally a new balance mechanism is designed and simulation results show that it completely balances inertial forces to improve the engine’s noise vibration and harshness performance.

摘要：Some concepts of virtual product are discussed. The key technologies ofvirtual fuel-pump development are in detail analysed, which include virtual fuel-pump productmodeling, intelligent simulation, distributed design environment, and virtual assembly. The virtualfuel-pump development prototype system considers requirement analysis, concept design, injectionpreferment analysis, detailed design, and assembly analysis.

摘要：The current computer-aided technologies in design and product development, the evolution of CAD modeling, and a framework of multi-volume CADmodeling system for heterogeneous object design and fabrication are presented inthis paper. The multi-volume CAD modeling system is presented based on nonmanifold topological elements. Material identifications are defined as design attributes introduced along with geometric and topological information at the designstage. Extended Euler operation and reasoning Boolean operations for merging andextraction are executed according to the associated material identifications in thedeveloped multi-volume modeling system for heterogeneous object. An applicationexample and a pseudo-processing algorithm for prototyping of heterogeneous structure through solid free-form fabrication are also described.

摘要：A novel method of realizing the optimal transmission of the crank-and-rockermechanism is presented. The optimal combination design is made by finding the related optimaltransmission parameters. The diagram of the optimal transmission is drawn. In the diagram, therelation among mini-mum transmission angle, the coefficient of travel speed variation, theoscillating angle of the rocker and the length of the bars is shown, concisely, conveniently anddirectly. The method possesses the main characteristic. That it is to achieve the optimaltransmission parameters under the transmission angle by directly choosing in the diagram, accordingto the given requirements. The characteristics of the mechanical transmission can be improved togain the optimal transmission effect by the method. Especially, the method is simple and convenientin practical use.

摘要：The optimal process conditions of an injection molded polypropylenes dustpan were investigated to improve the part quality. A fractional factorial experiment was employed to screen the significant factors and main combinations among the numerous process parameters. And, with the consideration of interaction effects, an L27 orthogonal array based on the Taguchi method was conducted to determine the optimal process conditions. The results indicate that the melt temperature has the most remarkable influence on both the volume shrinkage and sink marks criterion weights. But the optimal process conditions and the order of influence are different for the two criterion weights.

摘要：Optimization design of hydraulic manifold blocks (HMB) is studied as acomplex solid spatial layout problem. Based on comprehensive research into structure features anddesign rules of HMB, an optimal mathematical model for this problem is presented. Usinghuman-computer cooperative genetic algorithm (GA) and its hybrid optitation strategies, integratedlayout and connection design schemes of HMB can be automatically optimized. An example is given totestify it.

摘要：Structural bionic design lacks mature and scientific theories, and the excellent structural characteristics of natural organisms sometimes cannot be transferred into engineering structures effectively. Aiming at overcoming the existing problems, this paper summarizes three related theories: similarity theory, fuzzy evaluation theory and optimization theory. Based on the related theories, a method of structural bionic design is introduced, which includes four steps: selecting the most useful structural characteristic of natural organism; analyzing the structural characteristic finally chosen for engineering problem; completing the structural bionic design for engineering structure; and verifying the structural bionic design. Similarity theory and fuzzy evaluation theory are employed to achieve Step 1. In Step 2 and Step 3, optimization theory is employed to analyze the parameters of structures. Together with the thoughts of simplification and grouping, optimization theory can reveal the relationship between organism structure and engineering structure, providing a way to structural bionic design. A general evaluation criterion is proposed in Step 4, which is feasible to evaluate the performance of different structures. Finally, based on the method, a structural bionic design of thin-walled cylindrical shell is introduced.

摘要：A concept of Specific Structure Efficiency (SSE) was proposed that can be used in the lightweight effect evaluation *** main procedures of bionic structure design were introduced *** parameter relationship betweenhollow stem of plant and the minimum weight was deduced in *** order to improve SSE of pylons, the structural characteristicsof hollow stem were investigated and *** pylon was designed based on analogous biological *** finite element method based simulation, the displacements and stresses in the bionic pylon were comparedwith those of the conventional *** show that the SSE of bionic pylon is improved ***, dynamic andelectromagnetism tests were carried out on conventional and bionic *** weight, stress, displacement and Radar CrossSection (RCS) of both pylons were *** results illustrate that the SSE of bionic pylon is markedly improvedthat specific strength efficiency and specific stiffness efficiency of bionic pylon are increased by 52.9% and 43.6% *** RCS of bionic pylon is reduced significantly.

摘要：A concept of an intelligent optimal design approach is proposed, which isorganized by a kind of compound knowledge model. The compound knowledge consists of modularizedquantitative knowledge, inclusive experience knowledge and case-based sample knowledge. By usingthis compound knowledge model, the abundant quantity information of mathematical programming and thesymbolic knowledge of artificial intelligence can be united together in this model. The intelligentoptimal design model based on such a compound knowledge and the automatically generateddecomposition principles based on it are also presented. Practically, it is applied to theproduction planning, process schedule and optimization of production process of a refining &chemical work and a great profit is achieved. Specially, the methods and principles are adaptablenot only to continuous process industry, but also to discrete manufacturing one.