The Triple-shear Unified Yield Criterion and Its Applications

摘要

By taking account of the functions of shear stress couples acting on the dodecahedron element, a triple-shear unified yield criterion for materials is proposed to interpret a series of criteria, especially the commonly used criteria such as the Tresca's yield criterion, the Von Mises's yield criterion and the Mohr-Coulomb's failure criterion through changing its contributive coefficient of the intermediate principal shear stress couples b and the tensile to compressive yield limit ratio a. In spite of that, problems of the limit inner pressures for thin and thick-wall cylinders are analyzed and the new unified solutions are deduced under the hypothesis of the perfectly elasto-plastic materials. The classical solutions based on the Tresca's yied criterion, the Von Mises's yield criterion and the Mohr-Coulomb's failure yield criterion are only the special cases of the new unified solutions. Detailed analyses show that both the contributive coefficient of the intermediate principal shear stress couples b and the tensile to compressive yield limit ratio a have influences on the limit inner pressures for thin and thick-wall cylinders.