A procedure for reanalysis of various structures subjected tovarious topologic modifi- cations is presented. The procedure isbased on the results of a single exact analysis and the factoriza-tion of the stiffness matr...A procedure for reanalysis of various structures subjected tovarious topologic modifi- cations is presented. The procedure isbased on the results of a single exact analysis and the factoriza-tion of the stiffness matrix of initial structures. It is suitablefor the addition of joints, where the number of the degrees offreedom is increased. The method deals with the stiffness matrix ofstruc- tures directly, so it can be used with a general finiteelement system. It is shown that the proposed ap- proximation methodis most effective in terms of accuracy, efficiency, and ease ofimplementation.展开更多
The virtual laminated element method (VLEM) can resolve structural shap e optimization problems with a new method. According to the characteristics of V LEM , only some characterized layer thickness values need be def...The virtual laminated element method (VLEM) can resolve structural shap e optimization problems with a new method. According to the characteristics of V LEM , only some characterized layer thickness values need be defined as design v ariables instead of boundary node coordinates or some other parameters determini ng the system boundary. One of the important features of this method is that it is not necessary to regenerate the FE(finite element) grid during the optimizati on process so as to avoid optimization failures resulting from some distortion grid elements. Th e thickness distribution in thin plate optimization problems in other studies be fore is of stepped shape. However, in this paper, a continuous thickness distrib ution can be obtained after optimization using VLEM, and is more reasonable. Fur thermore, an approximate reanalysis method named ″behavior model technique″ ca n be used to reduce the amount of structural reanalysis. Some typical examples are offered to prove the effectiveness and practicality of the proposed method.展开更多
文摘A procedure for reanalysis of various structures subjected tovarious topologic modifi- cations is presented. The procedure isbased on the results of a single exact analysis and the factoriza-tion of the stiffness matrix of initial structures. It is suitablefor the addition of joints, where the number of the degrees offreedom is increased. The method deals with the stiffness matrix ofstruc- tures directly, so it can be used with a general finiteelement system. It is shown that the proposed ap- proximation methodis most effective in terms of accuracy, efficiency, and ease ofimplementation.
文摘The virtual laminated element method (VLEM) can resolve structural shap e optimization problems with a new method. According to the characteristics of V LEM , only some characterized layer thickness values need be defined as design v ariables instead of boundary node coordinates or some other parameters determini ng the system boundary. One of the important features of this method is that it is not necessary to regenerate the FE(finite element) grid during the optimizati on process so as to avoid optimization failures resulting from some distortion grid elements. Th e thickness distribution in thin plate optimization problems in other studies be fore is of stepped shape. However, in this paper, a continuous thickness distrib ution can be obtained after optimization using VLEM, and is more reasonable. Fur thermore, an approximate reanalysis method named ″behavior model technique″ ca n be used to reduce the amount of structural reanalysis. Some typical examples are offered to prove the effectiveness and practicality of the proposed method.
