Based on the elastic-plastic large deformation finite element formulation as well as the shell element combined discrete Kirchhoff theoretical plate element (DKT) with membrane square element, deep-drawing bending spr...Based on the elastic-plastic large deformation finite element formulation as well as the shell element combined discrete Kirchhoff theoretical plate element (DKT) with membrane square element, deep-drawing bending springback of typical U-pattern is studied. At the same time the springback values of the drawing of patterns' unloading and trimming about the satellite aerial reflecting surface are predicted and also compared with those of the practical punch. Above two springbacks all obtain satisfactory results, which provide a kind of effective quantitative pre-prediction of springback for the practical engineers.展开更多
In isogeometric analysis(IGA),the boundary representation of computer-aided design(CAD)and the tensor-product non-uniform rational B-spline structure make the analysis of three-dimensional(3D)problems with irregular g...In isogeometric analysis(IGA),the boundary representation of computer-aided design(CAD)and the tensor-product non-uniform rational B-spline structure make the analysis of three-dimensional(3D)problems with irregular geometries difficult.In this paper,an IGA method for complex models is presented by reconstructing analysis-suitable models.The CAD model is represented by boundary polygons or point cloud and is embedded into a regular background grid,and a model reconstruction method is proposed to obtain the level set function of the approximate model,which can be directly used in IGA.Three 3D examples are used to test the proposed method,and the results demonstrate that the proposed method can deal with complex engineering parts reconstructed by boundary polygons or point clouds.展开更多
基金This project is supported by National Natural Science Foundation of China (No.19832020)Provincial Natural Science Foundation of Jilin (No.20000519)
文摘Based on the elastic-plastic large deformation finite element formulation as well as the shell element combined discrete Kirchhoff theoretical plate element (DKT) with membrane square element, deep-drawing bending springback of typical U-pattern is studied. At the same time the springback values of the drawing of patterns' unloading and trimming about the satellite aerial reflecting surface are predicted and also compared with those of the practical punch. Above two springbacks all obtain satisfactory results, which provide a kind of effective quantitative pre-prediction of springback for the practical engineers.
基金This work has been supported by the National Key R&D Program of China(Grant No.2020YFB1708300)the National Natural Science Foundation of China(Grant Nos.52075184 and 51705158)the Research Grants Council via Early Career Scheme,Hong Kong,China(RGC Ref.No.27209817)。
文摘In isogeometric analysis(IGA),the boundary representation of computer-aided design(CAD)and the tensor-product non-uniform rational B-spline structure make the analysis of three-dimensional(3D)problems with irregular geometries difficult.In this paper,an IGA method for complex models is presented by reconstructing analysis-suitable models.The CAD model is represented by boundary polygons or point cloud and is embedded into a regular background grid,and a model reconstruction method is proposed to obtain the level set function of the approximate model,which can be directly used in IGA.Three 3D examples are used to test the proposed method,and the results demonstrate that the proposed method can deal with complex engineering parts reconstructed by boundary polygons or point clouds.
