A study on inversion of metallic thin-walled conical shells

Abstract

The paper presents an experimental and computational study of the inversion process of metallic thin-walled conical shells subjected to axial compression. The study mainly focuses on two aspects: firstly, to optimise the semi-apical angle of a cone to get a constant collapse load and secondly, to study the mechanics of the development of the inversion mode of collapse. Axial compression of aluminium thin-walled conical shells of semi-apical angles between 8° and 11° was performed on a universal testing machine Instron. An axisymmetric finite element computational model of the development of the inversion mode of collapse is also presented and analysed, using a non-linear finite element code FORGE2. Six-noded triangular elements are used for discretising the deforming shell domain. The material of the shells is idealised as rigid viscoplastic. Experimental and computed results are compared to validate the computational model. On the basis of the obtained results, the development of the axisymmetric inversion mode of collapse is presented, analysed and discussed.