LS-DYNA

Abstract: Maximising impact protection of fibre reinforced plastic (FRP) laminated composite structures and predicting and preventing the negative effects of impact on these structures are paramount design criteria for ground and space vehicles. In this paper the low velocity impact response of these structures will be investigated. The current work is based on the application of explicit finite element software for modelling the behaviour of laminated composite plates under low velocity impact loading and it explores the impact, post impact and failure of these structures. Three models, namely thick shell elements with cohesive interface, solid elements with cohesive interface, and thin shell elements with tiebreak contact, were all developed in the explicit nonlinear finite element code LS-DYNA. The FEA results in terms of force and energy are validated with experimental studies in the literature. The numerical results are utilized in providing guidelines for modelling and impact simulation of FRP laminated composites, and recommendations are provided in terms of modelling and simulation parameters such as element size, number of shell sub-laminates, and contact stiffness scale factors.

Abstract: After discussing general properties of implicit FE analysis using ANSYS and explicit analysis using LS-DYNA it is shown when and how quasi-static limit load analyses can be performed by a transient analysis using explicit time integration. Then we focus on the remaining benefits of implicit analysis and how a proper combination of ANSYS and LS-DYNA can be used to prepare the transient analysis by common preprocessing and static analysis steps. Aspects of discretization, solution control, consideration of imperfections and methods of checking the results are outlined.