von Mises yield criterion

About: von Mises yield criterion is a research topic. Over the lifetime, 4374 publications have been published within this topic receiving 82642 citations. The topic is also known as: Von Mises stress.

Von Mises' yield criterion and nonlinearly hardening rotating shafts

Abstract: A computational model is developed to estimate the stress distributions in rotating elastic-plastic solid and hollow shafts by the use of von Mises’ yield criterion, deformation theory of plasticity and a Swift-type hardening law. An efficient numerical solution procedure based on the shooting method and Newton iterations is designed and used throughout this work to treat shafts with fixed and free ends. The results of the computations are verified by comparison with analytical solutions in the elastic range as well as with analytical elastic-plastic solutions employing Tresca’s yield criterion available in the literature. The stresses, displacement and plastic strains are computed for nonlinearly hardening elastic-plastic solid and hollow shafts rotating at different speeds, and the results are presented in graphical form.

A Yield Criterion for Porous Ductile Media at High Strain Rate

Abstract: An approximate yield criterion for porous ductile media at high strain rate is developed adopting energy principles. A new concept that the macroscopic stresses are composed of two parts, representing dynamic and quasi-static components, is proposed. It is found that the dynamic part of the macroscopic stresses controls the movement of the dynamic yield surface in stress space, while the quasi-static part determines the shape of the dynamic yield surface. The matrix material is idealized as rigid-perfectly plastic and obeying the von Mises yield. An approximate velocity field for the matrix is employed to derive the dynamic yield function. Numerical results show that the dynamic yield function is dependent not only on the rate of deformation but also on the distribution of initial micro-damage, which are different from that of the quasi-static condition. It is indicated that inertial effects play a very important role in the dynamic behavior of the yield function. However, it is also shown that when the rate of deformation is low (≤10 3 /sec), inertial effects become vanishingly small, and the dynamic yield function in this case reduces to the Gurson model.

A Numerical Investigation of the Thermal Stresses of a Planar Solid Oxide Fuel Cell

Abstract: A typical operating temperature of a solid oxide fuel cell (SOFC) is quite high above 750 °C and affects the thermomechanical behavior of the cell. Thermal stresses may cause microstructural instability and sub-critical cracking. Therefore, a joint analysis by the computational fluid dynamics (CFD) and computational structural mechanics based on the finite element method (FEM) was carried out to analyze thermal stresses in a planar SOFC and to predict potential failure locations in the cell. A full numerical model was based on the coupling of thermo-fluid model with the thermo-mechanical model. Based on a temperature distribution from the thermo-fluid model, stress distribution including the von Mises stress, shear stress as well as the operating principal stress were derived in the thermo-mechanical model. The FEM calculations were performed under different working conditions of the planar SOFC. The highest total stress was noticed at the lower operating voltage of 0.3 V, while the lowest total stress was determined at the voltage of 0.7 V. The obtained stress distributions allowed a better understanding of details of internal processes occurring within the SOFC and provided helpful guidance in the optimization of a new SOFC design.