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The load carrying capacity of steel structures, built of slender members like bridge cross‐sections, depends on coupled yielding and buckling of the stringers and the plate strips as well as on the global buckling. Therefore, the common techniques of modelling the limit load by an elasto‐plastic layer model fail. In order to overcome the difficulty a material law is developed, in which local buckling failure and yielding is considered. This is based on an energy function, which describes the elasto‐plastic intermediate and ultimate state of plates and webs dependent on only a few parameters. The application is shown on large scale examples of stiffened steel bridge decks.

This paper deals with the optimum design of composite laminated plates. Both ply orientation angles and ply thicknesses of the composite plate are used as design variables. The optimum design process is divided into two sublevels. In the first sublevel, the strain energy of the plate is minimized by changing the ply orientation angles while the ply thickness distributions remain unmodified. In the second sublevel, with the angle values obtained in the first sublevel, the optimum thickness distribution of each ply is obtained by minimizing the structural weight while satisfying stiffness and gauge constraints. The final optimum design is achieved by iterating between these two sublevels. The stiffness analysis is performed by the finite element method in which a triangular element is used that is suitable for from thin to thick plates and includes the transverse shear effects. All the derivative analysis is performed analytically. The mathematical programming method called Constrained Variable Metric is used to solve the optimum problem. An example is provided for a rectangular laminated plate with good results to show the effectiveness of the method.

The paper desribes an energy‐based framework for a simple model with two degrees‐of‐freedom that statically exhibits bifurcations or limit‐points. Dynamically, the equivalent system may respond with small amplitude motion (being dynamically stable) or it may ‘escape’ and move to exhibit ‘large amplitude motion’ (thus becoming dynamically unstable). The energy framework is used to define bounds for these stable and unstable motions. These bounds are used to provide a framework for a set of dynamic finite element computations based on conventional finite element techniques.

This paper gives a review of the finite element techniques (FE) applied in the area of material processing. The latest trends in metal forming, non‐metal forming, powder metallurgy and composite material processing are briefly discussed. The range of applications of finite elements on these subjects is extremely wide and cannot be presented in a single paper; therefore the aim of the paper is to give FE researchers/users only an encyclopaedic view of the different possibilities that exist today in the various fields mentioned above. An appendix included at the end of the paper presents a bibliography on finite element applications in material processing for 1994‐1996, where 1,370 references are listed. This bibliography is an updating of the paper written by Brannberg and Mackerle which has been published in Engineering Computations, Vol. 11 No. 5, 1994, pp. 413‐55.

An efficient algorithm to estimate the large elasto‐plastic strains encountered in thin sheet metal forming parts has been continuously developed by the authors since 1987. The algorithm is based on a finite element discretization of the known final shape. In this paper a new simple triangular shell element with constant membrane and bending strains is presented using discrete Kirchhoff constraints. The expressions of the internal force vector and logarithmic strains through the thickness are derived. Two applications are considered to discuss the validity and efficiency of the numerical procedure.

Coupled problems are of great interest in the area of technical applications. In the current paper we present the theory of thermo‐electro‐mechanical coupling and provide a discretization by using the method of finite elements. The thermo‐electro‐mechanical effect presents a physical interaction between the fundamental quantities of the sub‐domains elastomechanics, electrostatics and heat balance. Throughout thermodynamic analysis we derive the constitutive equations which describe the above behaviour and relate the main quantities which describe the three fields. From the principal equations of elastomechanics, electrostatics and heat balance separately, we derive the weak formulation of the load equilibrium, the electrostatic equilibrium and the heat balance individually. Furthermore a FE‐formulation leads the weak formulations of the coupled problem to a system of three coupling differential equations. This system is non‐linear with respect to the temperature and we solve it using an incremental solution. The numerical result is to be shown on a one‐dimensional test example.

The purpose of this paper is to present several two‐dimensional plate elements for the analysis of shear actuated laminate.

The limitations of the classical formulations based on the principle of virtual displacements in depicting the peculiar behavior of the transverse and normal stresses of multilayered structures have been easily overcome by using the mixed variational theorem proposed by Reissner (Reissner mixed variational theorem). In the framework of a unified formulation (UF), the assumptions of the unknowns is made through a common expansion leading both to global and layerwise description of the assumed unknowns. In addition, the possibility to choose the order of the expansion between one and four allows to be derived and compared 22 different plate models. The performances of the proposed elements have tested on application for whom an exact solution is available in open literature.

The obtained results complain quite well with the exact ones even if the need of advanced plate models come to evidence.

This paper describes how the capabilities of the UF to accurately analyze multilayered structures exploiting the shear mode actuation have been tested and states that in order to extend the capabilities of the UF, further efforts should be made toward the assumptions of discontinuous electric fields (potential and normal displacement). The paper confirms the need for advanced higher order plate models in modeling of adaptive laminate.

A database for finite element models and related data is developed and incorporated into a prototype system for integration of non‐linear finite element codes with a product design system. In the prototype system, the database is used as a link for integrating commercial, public domain as well as in‐house codes. In the present system, the public domain finite element codes NIKE2D, NIKE3D, DYNA2D, DYNA3D and TOPAZ2D are integrated with the CIM–system I–DEAS. The prototype system is primarily intended as a platform in research projects for development of integrated environments tuned for simulations of specific manufacturing processes such as quenching, welding, hot rolling, metal powder compaction and hot isostatic pressing.

Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.

Finite Elements FE based on the Reissner’s Mixed Variational Theorem RMVT, for the analysis of multilayered plates subjected to magneto‐electro‐elastic MEE fields, are developed in this work. Accurate description of the various field variables has been provided by employing a variable kinematic model which is based on the Carrera’s Unified Formulation CUF. Displacements, transverse shear/normal stresses, magnetic and electric potentials have been chosen as independent unknowns. Interlaminar continuity of mechanical variables is “a priori” guaranteed by the RMVT application. Layer‐wise plate elements with linear up to fourth order distribution in the thickness direction have been compared. FE governing equations, according to CUF, are presented in terms of fundamental nuclei whose form is not affected by kinematic assumptions. Results show the effectiveness of the proposed elements, the superiority of mixed FEs with respect to the classical ones, as well as their capability, by choosing appropriate kinematics, to accurately trace the static response of laminated plates subject to magneto‐electro‐elastic fields.