one of the new research fields in plasticity is related to choosing a proper non-associated flow rule (nafr), instead of the associated one (afr), to predict the experimental results more accurately. the idea of the current research is derived from combining von mises and tresca criteria in the places of yield and plastic potential surfaces in rate-independent plasticity.  this idea is implemen...

A macroscopic model describing elastic-plastic solids is derived in a special case of the internal specific energy taken in separable form: it is the sum of a hydrodynamic part depending only on the density and entropy, and a shear part depending on other invariants of the Finger tensor. In particular, the relaxation terms are constructed compatible with the von Mises yield criteria. In additio...

In this paper, the upper bound limit analysis of thin plates in bending is addressed using various types of triangular finite elements for the generation of velocity fields and second order cone programming (SOCP) for the minimization problem. Three different C-discontinuous finite elements are considered : the quadratic 6 node Lagrange triangle (T6), an enhanced T6 element with a cubic bubble ...

The paper proposes a method of strength analysis for materials thin-walled shell structures reinforced with stiffeners. shells under consideration were made orthotropic materials. authors analyze the applicability following seven criteria: maximum stress criterion, Mises-Hill Fisher Goldenblatt-Kopnov Liu-Huang-Stout Tsai-Wu and Hoffman criterion. During study, doubly-curved shallow square in p...

BACKGROUND Stress shielding in the cemented hip prosthesis occurs due to the mismatching in the mechanical properties of metallic stem and bone. This mismatching in properties is considered as one of the main reasons for implant loosening. Therefore, a new stem material in orthopedic surgery is still required. In the present study, 3D finite element modeling is used for evaluating the artificia...

The purpose of this paper is to examine the piston stress distribution using several thicknesses of the coating materials to achieve higher gasoline engine performance. First of all, finite element structure analysis is used to uncoated petrol piston made of aluminum alloy. Then, steel and cast iron piston materials are conducted and compared with the aluminum piston. After that, investigation ...

To achieve accurate and precise results of finite element analysis (FEA) of bones, it is important to represent the load/boundary conditions as identical as possible to the human body such as the bone properties, the type and force of the muscles, the contact force of the joints, and the location of the muscle attachment. In this study, the difference in the Von-Mises stress and the total defor...

OBJECTIVES No studies have compared monoaxial and polyaxial pedicle screws with regard to the von Mises stress of the instrumentation, intradiscal pressures of the adjacent segment and adjacent segment degeneration. METHODS Short-segment monoaxial/polyaxial pedicle screw fixation techniques were compared using finite element methods, and the redistributed T11-L1 segment range of motion, large...