Meshes in the sheet of Laminated Object Manufacturing (LOM) are now designedwith the same size, and the length of mesh lines may be as several times as the outline length.The method of variablesize meshes is advanced ...Meshes in the sheet of Laminated Object Manufacturing (LOM) are now designedwith the same size, and the length of mesh lines may be as several times as the outline length.The method of variablesize meshes is advanced in this paper. Meshes in a sheet are designed ac-cording to the difficulty of removing the waste in or out of the outlines. The CAD model may bedivided into several segments in Z direction with different mesh sizes. The length of mesh lineswould be largely decreased and the manufacturing efficiency would be improved.展开更多
为了达到无需火箭辅助而增大射程,对国外采用弹体斜翼/尾翼的方式增加弹药射程的方案进行了介绍;该设计方案具有智能舵机控制,制导弹药从超音速、音速,到亚音速的整个滑行阶段,均将保持最大升阻比;为了分析超音速与音速滑行阶段内给定...为了达到无需火箭辅助而增大射程,对国外采用弹体斜翼/尾翼的方式增加弹药射程的方案进行了介绍;该设计方案具有智能舵机控制,制导弹药从超音速、音速,到亚音速的整个滑行阶段,均将保持最大升阻比;为了分析超音速与音速滑行阶段内给定的马赫数与攻角时不同斜翼的最佳后掠角状态,利用重叠网格法进行了系统的纳维-斯托克斯方程计算,通过对斜翼的最优配置设计,无需火箭助推便可使弹药达到100 n mile的目标射程。展开更多
An essential step for the realization of free-form surface structures is to create an efficient structural gird that satisfies not only the architectural aesthetics,but also the structural performance.Employing the ma...An essential step for the realization of free-form surface structures is to create an efficient structural gird that satisfies not only the architectural aesthetics,but also the structural performance.Employing the main stress trajectories as the representation of force flows on a free-form surface,an automatic grid generation approach is proposed for the architectural design.The algorithm automatically plots the main stress trajectories on a 3D free-form surface,and adopts a modified advancing front meshing technique to generate the structural grid.Based on the proposed algorithm,an automatic grid generator named "St-Surmesh" is developed for the practical architectural design of free-form surface structure.The surface geometry of one of the Sun Valleys in Expo Axis for the Expo Shanghai 2010 is selected as a numerical example for validating the proposed approach.Comparative studies are performed to demonstrate how different structural grids affect the design of a free-form surface structure.展开更多
文摘Meshes in the sheet of Laminated Object Manufacturing (LOM) are now designedwith the same size, and the length of mesh lines may be as several times as the outline length.The method of variablesize meshes is advanced in this paper. Meshes in a sheet are designed ac-cording to the difficulty of removing the waste in or out of the outlines. The CAD model may bedivided into several segments in Z direction with different mesh sizes. The length of mesh lineswould be largely decreased and the manufacturing efficiency would be improved.
文摘为了达到无需火箭辅助而增大射程,对国外采用弹体斜翼/尾翼的方式增加弹药射程的方案进行了介绍;该设计方案具有智能舵机控制,制导弹药从超音速、音速,到亚音速的整个滑行阶段,均将保持最大升阻比;为了分析超音速与音速滑行阶段内给定的马赫数与攻角时不同斜翼的最佳后掠角状态,利用重叠网格法进行了系统的纳维-斯托克斯方程计算,通过对斜翼的最优配置设计,无需火箭助推便可使弹药达到100 n mile的目标射程。
基金Project(51378457)supported by the National Natural Science Foundation of China
文摘An essential step for the realization of free-form surface structures is to create an efficient structural gird that satisfies not only the architectural aesthetics,but also the structural performance.Employing the main stress trajectories as the representation of force flows on a free-form surface,an automatic grid generation approach is proposed for the architectural design.The algorithm automatically plots the main stress trajectories on a 3D free-form surface,and adopts a modified advancing front meshing technique to generate the structural grid.Based on the proposed algorithm,an automatic grid generator named "St-Surmesh" is developed for the practical architectural design of free-form surface structure.The surface geometry of one of the Sun Valleys in Expo Axis for the Expo Shanghai 2010 is selected as a numerical example for validating the proposed approach.Comparative studies are performed to demonstrate how different structural grids affect the design of a free-form surface structure.
