The Application Of Response Surface Methodology In Some Practical Projects Of Optimization

Structural and multi-disciplinary optimization design is the application of optimization method in structural and multi-disciplinary design fields, which fulfils searching optimum solution in feasible zone with optimum object, such as the least material, cost, and the simplest working procedure etc. In the practice of structural and multi-disciplinary optimization design, it is difficult to convert physical model to mathematical model, while it can be successfully solved by an approximate method named Response Surface Methodology.In the paper, Response Surface Methodology was applied to Coronary Artery Bypass Graft and 300 ton ladle optimization design, which are very different subjects to resolve. The work is achieved as follows.(1) The general programme and interface for user about solution of response surface's coefficients were designed. The user may obtain the coefficients of response surface in output file when input file was done and form of response surface was selected.(2) The plane model of Coronary Artery Bypass Graft was established in the platform of analysis software. Using Response Surface Methodology, optimization design was applied to geometric factors mainly includeing graft-host diameter ratio (diameter ratio for short) and junction angle. It is indicated that large diameter ratio and small junction angle are advisable to be adopted with the help of clinic experience and optimization design. Furthermore, the influence of diameter in stenosis region to postoperative hemodynamics was investigated, and the function of diameter ratio, junction angle and critical diameter in stensis region was fitted, which has instructional significance in mastering chance of operation.(3) The finite element model of 300 ton ladle was constructed, and the optimization design was applied to thickess of ladle's wall and bottom by Response Surface Methodology, with the aim reduceing weight. It is shown that the optimized ladle may satisfy the demand of use and security, and the weight is reduced.In summary, Response Surface Methodology is effective method in solving practical problems of optimization design, its applicability is universal.