The Triple-shear Unified Yield Criterion and Its Applications.pdf

The Triple-shear Unified Yield Criterion and Its Applications Xiaorong Hu 1, a, Xiaomei Fan2,b 1 School of Civil Engineering and Architecture, Nanchang University, China 2 School of Resource and Civil Engineering, Liaoning Institute of Science and Technology, China a huxiaorong@, b bxfanxiaomei@126.com Keywords: triple-shear unified yield criterion; shear stress couples, functions of the shear stress couple ; limit inner pressures; cylinders. Abstract. 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 α . 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 ratioα have influences on the limit inner pressures for thin and thick-wall cylinders. Introduction The yield characteristics for materials vary significantly due to their complicated microscopic structures, even though for the isotropic homogeneous materials [1-3]. In order to describe their different yield properties, the yield criteria widely used nowadays are the Tresca’s yield criterion, the Von Mises’s yield criterion and the Mohr-Coulomb’s yie