Thermal distortion evaluation by three-dimensional geometric reasoning

If manufacturing incompatibility of a product can be evaluated at the early product design stage, the designers can modify their design to reduce the effect of potential manufacturing problems. This will result in fewer manufacturing problems, less redesign, less expensive tooling, lower cost, better quality, and shorter development time. For a given design, geometric reasoning can predict qualitatively the behaviors of a physical manufacturing process by representing and reasoning with incomplete knowledge of the physical phenomena. It integrates a design with manufacturing processes to help designers simultaneously consider design goals and manufacturing constraints during the early design stage. The geometric reasoning approach can encourage design engineers to qualitatively evaluate the compatibility of their design with manufacturing limitations and requirements. Casting distortion not only influences the quality of the product but also the manufacturing procedure of a die-casting.; Casting distortion problems can be reduced during part design. By evaluating the distortion tendencies of a given design, the designers can modify their design to reduce these effects and reduce manufacturing problems. A geometric reasoning approach has been developed to qualitatively evaluate casting distortion. The geometric reasoning can predict the casting distortion pattern based on the geometric and topologic information of the design. In addition, it can extract the design characteristics that cause the distortion-related problems. The results of the geometric reasoning can be used to support the ejectability evaluation for a given casting design and the ejector pin layouts. Through geometric reasoning, the constrained surfaces are determined and the ejection load developed on them is qualitatively evaluated based on the geometric and topologic information describing the part. In addition, several evaluation functions, such as the effective relative ejection force rating of each ejector pin, ejection moment, ejection pattern, the ratio of the ejection load on the ejector die to that on cover die, are defined and evaluated.; The information obtained from the reasoning can give casting designers manufacturability feedback about their design and will help them make design decisions to reduce the potential manufacturing defects related to casting distortion. In addition, the information obtained from the reasoning can give die designers an evaluation about their ejector pin design and will help them make design decisions in locating ejector pins and orienting the part in the die to reduce the ejection-related defects.