the collapse of a compression member gives rise to decrease of the load carrying capacity of the member. to perform a nonlinear analysis, in addition to the precritical behavior, the post-critical behavior of the compression member also must be determined. in this study, because of certain advantages of the finite element method, this method has been selected to evaluate the axial load-axial di...

The mixed method for the biharmonic problem introduced in [12] is extended to the Reissner-Mindlin plate model. The Reissner-Mindlin problem is written as a system of first order equations and all the resulting variables are approximated. However, the hybrid form of the method allows one to eliminate all the variables and have a final system only involving the Lagrange multipliers that approxim...

The theoretical background of mixed finite element models, in general for nonlinear problems, is briefly reexamined. In the first part of the paper, several alternative “mixed” formulations for 3-D continua undergoing large elastic deformations under the action of time dependent external loading are outlined and are examined incisively. It is concluded that mixed finite element formulations, wh...

in the recent paper, one of the numerical methods without element, for static analysis of thin plates displacement based on classical plates theory (cpt), has been presented. in this method, the domain of problem solving is shown only by the means of a set of nodes, and there is no need to any mesh scheme or element. one of the kinds of element free methods used here is the radial point interpo...

A technique of idealising frame models using substructures is outlined. All joints are modelled in 3D but, using substructures, each 3D joint is converted to an equivalent stiffness element. The slender regions between the joints are modelled using beam elements. Coupling between the substructures and beam elements is carried out in a manner that conforms with the theory of elasticity. Post-ela...

This paper presents a new continuum shape sensitivity method for calculating the mixed-mode stress-intensity factors of a stationary crack in two-dimensional, linear-elastic, orthotropic functionally graded materials with arbitrary geometry. The method involves the material derivative concept taken from continuum mechanics, the mutual potential energy release rate, and direct differentiation. S...

This work presents a numerical approach in order to predict the influence of implant material stiffness in a femoral component design when submitted in compression. The implant success depends on the transferred load to the neighboring bone. The finite element method can be used to analysis the stress and strain distribution in the femoral component allowing to improve the implant selection. Fo...

The testing of mode III and mixed mode failure is every so often encountered in the dedicated literature of mechanical characterization of brittle and quasi-brittle materials. In this work, the application of the mixed strain displacement ε − u finite element formulation to three examples involving skew notched beams is presented. The use of this FE technology is effective in problems involving...

We study finite element methods for the displacement obstacle problem of clamped Kirchhoff plates. A unified convergence analysis is provided for C1 finite element methods, classical nonconforming finite element methods and C0 interior penalty methods. Under the condition that the obstacles are sufficiently smooth and that they are separated from each other and the zero displacement boundary co...