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Abstract: Stress peening forming is widely used in the aeronautics industry to induce curvatures in wing skins. Most of the investigations of stress peen forming are empirical and experimental. In this paper, a three step numerical model that can simulate this process was developed. First, an implicit Finite Element Analysis (FEA) with ANSYS where a prebending moment along the spanwise direction of the component was performed. Then, an explicit FEA with LS-DYNA simulating shot impacts on the pre-stressed component was executed in order to obtain the resulting stresses inside the component. Finally, an implicit FEA with ANSYS was performed for calculating the arc heights and the curvature radii of the component in chordwise and spanwise directions. Numerical analysis of the process shows that the prebending moments have an influence not only on the residual stress profiles but also on the curvatures of the deformed component in chordwise and spanwise directions. This model was used to establish a relationship between the prebending moment and the resulting arc heights and residual stress profiles. The numerical strategies developed in this paper supply a useful tool for studying and optimizing the stress peening process. [Copyright &y& Elsevier]

Abstract: In the comparison with the theoretical analyses of wire strands reported in the literature where obviously single-layered strands with a construction of the 1+6 wires were modelled and analysed, this paper is focused on a multi-layered strand with a construction of the 1+6+12+18 wires. The geometric parametric equations developed in the first part of this paper are implemented in CATIA V5 software code for geometric modelling of the multi-layered strand. The methodology of their implementation and the approach for the generation of the strand geometric model are demonstrated. To predict the behaviour of the multi-layered strand under tensile loads, the mathematical geometric model is further implemented in a finite element program. For this purpose ABAQUS/Explicit software is used. The derived 3D geometric models of the multi-layered strands and the results of the finite element elastic behaviour analyses of the strand under tension loads are validated through comparisons with experimental and theoretical data available. The results obtained confirm the correctness of the derived parametric equations and mathematical and physical importance of the finite element model developed. [Copyright &y& Elsevier]

Abstract: In this paper the mathematical geometric models of the single-lay wire strands and double-lay wire ropes with defined initial parameters are presented. The present geometric models fully consider the single-helix configuration of individual wires in the strand and the double-helix configuration of individual wires within the wound strands of the ropes. The mathematical representation of the single and double helixes is in form of parametric equations with variable input parameters which determine the centreline of an arbitrary circular wire of the right hand lay and left hand lay strands and ropes of the Lang lay and regular lay construction. The concrete forms of the parametric equations are derived and presented. The application of the derived geometric analytical model is illustrated by numerical examples. Techniques for the implementation of the derived mathematical models in CATIA V5 software and procedures for the generation of the rope model are briefly presented. Correctness of the derived parametric equations and a performance of the generated rope model are controlled by visualizations. The application of the derived mathematical model and the development of a finite element model for the numerical simulation of the multi-layered strand under tension tests are treated in the second part of the paper . [Copyright &y& Elsevier]

Abstract: This paper presents the advanced object-oriented design of finite element representations in a complex multi-physics finite element environment OOFEM [1–3]. The focus is on reuse of existing single-physics capabilities when implementing elements for coupled simulations. This has been achieved by decoupling the description of element geometry, element problem specific capabilities, element interpolation, and integration schemes. The individual problem specific capabilities, represented by a hierarchy of classes derived form ElementEvaluator, can be assembled together to define an evaluator for coupled analysis. The presented design leads to an extremely flexible implementation, with clean modular design. The application is demonstrated on an implicit gradient formulation of a damage-plastic model and on coupled heat and mass transfer. [Copyright &y& Elsevier]