Study on measurement and evaluation criterion of wrinkling in drawing parts;

The critical wrinkling loads of sheet and shell are given,which are in the deformed region of deep-rawing.

On the basis of constructing wrinkling model,it is calculated that the wrinkling critical tangent pressure formula in the process of drawing.

The theory and experiment study on the rectangular sheet transverse buckling at high temperature;

Based on Hill s theory of orthotropic anisotropic plasticity and the energy method in the theory of stability, a critical equation of elastoplastic buckling of ananisotropic sheet is established, which is useful in the analysis of wrinkling or bucklingcaused by non-uniform stretching in press forming.

Alexander for the thin-walled tube under axial compression, this paper introduces a zoning model to analyze the end plastic wrinkling characteristic of the dieless thin-walled tube internal high pressure forming.

Analysis method on wall wrinkling of conical parts based on reverse moulding;

Based on elastic-plastic thin shell instability theory,adopted virtual power principle and nonlinear elastic-plastic finite element analysis,the buckling characteristic of Al-Mg-Si based alloy Square Sheet with Non-uniform Tension(called as YBT) were investigated.

The effects of the nonuniformity of porosity development and stress distribution on material bifurcations(plane shear bending and surface wrinkling)are investigated by means of numerical method.

Under the loading conditions of uniaxial and slightly biaxial tension,the characteristics of material bifurcations(plane shear banding and surface wrinkling)are demonstrated.