本研究應用光線演算法於結構最佳化設計中。光線演算法是一種利用光波的折射定律，在空間中調整光線步伐的方式尋找問題最佳解的方法。該法之特點為參數設定少及搜尋範圍廣。光線演算法將光波的折射定律運用空間座標概念推導出二維空間入射光線向量以及折射光線向量的關係式，再歸納出入射光線向量以及折射光線向量的範圍推導出高維空間的關係式，根據這些關係式定義出光線演算法的光線運動方向公式。本研究將ANSYS有限元素分析軟體中的APDL語法與FORTRAN程式結合成一系統程式，並以六種不同的範例執行結構最佳化設計。數值範例中將對各種結構做分析與討論。範例中將結構最佳化問題轉為數學函數，再利用光線演算法對結構系統執行最佳化設計。由數值分析範例之結果，發現光線演算法於結構最佳化設計上可得到不錯的結果。 The Ray Optimization (RO) algorithm was applied to the optimum design of structures in this study. The Snell’s refraction law of the light was used in RO algorithm which is inspired by transition of ray from one medium to another. The transition of ray is utilized for searching the global or near-global solution. The advantages of RO are less settings of parameter and extensive searching range. By using the Snell’s law, we can define the appropriate function for incident ray and the refracted light of vector in the two and three dimensional space in RO algorithm. Based on this function, the RO’s movement vector can be defined. The FORTRAN and APDL of ANSYS software are integrated into a systematic RO program. The optimization problem can be transformed into a mathematical function. Minimum weight design will be developed in six numerical examples. Then the optimum deign of structures can be obtained by RO. The results of RO are better than other references in the examples.
