Delamination of impacted composite structures by cohesive zone interface elements and tiebreak contact

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.

Coupled cohesive zone models for mixed-mode fracture: A comparative study

“…Several different ways exist to incorporate a CZM in a finite element setting, e.g. using interface elements [11,70,71] or generalized contact elements [72]. More recently, cohesive zone approaches have been proposed within extended FEM [73][74][75] and embedded mesh formulations [76,77], or using isogeometric discretizations [78][79][80][81].…”

Simulation Study of Adhesive Material for Sandwich Panel under Edgewise Compression Condition

“…where NLS is the maximum separation in the normal direction, TLS is the maximum separation in the tangential direction, 1 δ and 2 δ are the tangential relative displacements of mode II loading mode, and 3 δ is the normal relative displacement of mode I loading mode. NLS and TLS are the key values, representing the maximum normal and tangential separation of the contact surface.…”

“…The property of interfacial material between panel and core is a main topic on research. Dogan et al [3] compared the interlayer damage of fiber-reinforced composite material with MAT 185 and tiebreak contact under low-speed impact using LS-DYNA, and contrasted with experiment to get the optimal model. Meanwhile, it was proposed that the element size, number of material layers, and contact parameter have a great influence on the calculation results, and the follow-up research is necessary.…”

Investigation of the high velocity impact behavior of grid cylindrical composite structures

“…In fact these structures have the capabilities of simple composite structures and reinforcement composite structures simultaneously . Fiber buckling and fiber breakage, matrix cracking and fracture, shear damage modes, delamination , debonding between ribs and skin, large deformation and perforation, plastic deflections, and a combination of these damage mechanisms, are possible damage mechanisms which could happens to these structures during different loading situations.…”