A biarc-based shape optimization approach to reduce stress concentration effects  

作　　者：Liang Meng Wei-Hong Zhang Ji-Hong Zhu Liang Xia 

机构地区：[1]Engineering Simulation and Aerospace Computing (ESAC),Northwestern Polytechnical University

出　　处：《Acta Mechanica Sinica》2014年第3期370-382,共13页力学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(90916027,11002113,51275424,and 11172236);973 Program(2011CB610304);the 111 Project(B07050);the NPU Foundation for Fundamental Research(JC20120229)

摘　　要：In order to avoid stress concentration, the shape boundary must be properly designed via shape optimiza- tion. Traditional shape optimization approach eliminates the stress concentration effect by using free-form curve to present the design boundaries without taking the machin- ability into consideration. In most numerical control （NC） machines, linear as well as circular interpolations are used to generate the tool path. Non-circular curves, such as non- uniform rotational B-spline （NURBS）, need other more ad- vanced interpolation functions to formulate the tool path. Forming the circular tool path by approximating the opti- mal free curve boundary with arcs or biarcs is another op- tion. However, these two approaches are both at a cost of sharp expansion of program code and long machining time consequently. Motivated by the success of recent researches on biarcs, a reliable shape optimization approach is pro- posed in this work to directly optimize the shape boundaries with biarcs while the efficiency and precision of traditional method are preserved. Finally, the approach is validated by several illustrative examples.In order to avoid stress concentration, the shape boundary must be properly designed via shape optimiza- tion. Traditional shape optimization approach eliminates the stress concentration effect by using free-form curve to present the design boundaries without taking the machin- ability into consideration. In most numerical control （NC） machines, linear as well as circular interpolations are used to generate the tool path. Non-circular curves, such as non- uniform rotational B-spline （NURBS）, need other more ad- vanced interpolation functions to formulate the tool path. Forming the circular tool path by approximating the opti- mal free curve boundary with arcs or biarcs is another op- tion. However, these two approaches are both at a cost of sharp expansion of program code and long machining time consequently. Motivated by the success of recent researches on biarcs, a reliable shape optimization approach is pro- posed in this work to directly optimize the shape boundaries with biarcs while the efficiency and precision of traditional method are preserved. Finally, the approach is validated by several illustrative examples.

关 键 词：Structural shape optimization BIARC Curvefitting NURBS Stress concentration 

分 类 号：O343.4[理学—固体力学]