A Study on Objective Modeling and Multidisciplinary Optimization for Concurrent Engineering

通过对几个实际设计问题的计算机辅助设计系统的开发，研究了并行工程系统的目标建模和多学科优化技术。1.提出了面向复杂机械系统布局和几何设计的计算设计方法和目标建模框架。在该方法中，设计对象被表示为系统中各种元素之间的一组装饰关系，即设备、管道等，通过设计过程逐渐从系统结构扩展到精确的布局和几何。将所开发的系统应用于某空调机组的设计中，验证了该系统的正确性和有效性。2.将多学科优化技术应用于几种复杂机械系统的设计问题，为并行工程系统的开发提供了参考。设计问题涉及连杆机构、齿轮传动装置、车辆传动系等，在这些产品的设计过程中，由于包含了大量的功能规律，必须同时处理多个方面，如在连杆机构的设计中，必须对其连杆形状综合和结构强度设计进行多学科建模和优化。采用面向对象的建模方法和广义归约优化技术对问题进行形式化描述和求解。文中提出的设计方法也适用于包括上述设计在内的其他各类设计问题。

Objective modeling and Multidisciplinary Optimization Technique are studied for Concurrent Engineering Systems through the development of the computer aided design system for several actual design problems. The results obtained are summarized as follows :1.A framework of computational design method and objective modeling is proposed for layout and geometry design of complicated mechanical systems. In the method, a design object is represented with a set of decorative relationships among various elements of a system i.e., apparatus, piping etc., which is gradually extended form system structure to exact layout and geometry through the design process. The configuration to be designed is made to grow and refined through the design process with evaluating their functions, cost and manufacturability etc. The system developed is applied to the design of an air-conditioning unit, and its validity and effectiveness is ascertained.2.Multidisciplinary optimization technique is also applied for the design problems of several kind of complicated mechanical systems with referenced to the development on concurrent engineering system. The design problems developed here are link mechanisms, gear drive devices, vehicle power trains etc. In the design process of these products, various aspects must be dealt with concurrently and simultaneously, since they include a large umber of functional disciplines.For example, in the design of link mechanisms, the multidisciplinary modeling and optimization must be applied for its linkage shape synthesis and structural strength design. To formulize and solve the problem, an object-oriented modeling and a generalized reduced optimization technique are applied. And their effectiveness is ascertained.The design technique developed here is also applicable for other various kind of design problems including the above mentioned design.