Plastic Limit Analysis Of Cylindrical Shells Under Twin-shear Yield Criterion

Cylindrical shell structure is one of the familiar structural style in civil engineering, mechanical engineering, aviation, aerospace and other fields .As the flexible design can not fully display the plastic properties and the economy is not very well. so, it has great importance for engineering design in considering the plastic properties of the materials and analysising the plastic limit of the shell to determine its ultimate bearing capacity.Generally, the"Tresca"yield criterion is used to analysis the plastic limit of cylindrical shell. In this paper, using the sandwich shell assumption derives axisymmetric shell's internal forces yield condition based on the twin-shear stress yield criterion which is presented by Professor Mao Hongyu. The limit analysis of cylindrical shells under axisymmetric load is used the static method and energy method. It shows the limited load under the different loads and boundary conditions , and determines the corresponding internal force field and the displacement-speed fields. Enrich the plastic limit analysis of cylindrical shell under axisymmetric loads.This paper analysis that the limit load relates to the load type of the structure, boundary conditions and"c 2"which is geometric features value of the shell. The ultimate load of cylindrical shell changes with the geometric features value"c 2".