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A multi-model global-local approach to study free edge effects in laminated composites subjected to uniaxial in-plane loads is presented in this paper. Mixed layer-wise (LW) finite element (FE) model is used in critical free edge zone. Remaining part of plate is modelled by using higher order equivalent single layer (ESL) theory. A transition element is developed to ensure a compatibility between differently modelled subdomains. This combined model possesses traits of both ESL and LW mixed models. Higher order ESL predicts global parameters efficiently, on the other hand, mixed LW model captures the interlaminar stresses at local zones. Mixed LW model includes the transverse stresses as nodal degrees of freedom (DOF) ensuring continuity of the transverse stresses over layer interfaces without using any additional stress functions. Both, ESL and LW mixed models are developed by using three dimensional (3D) elasticity relationships and principle of minimum potential energy. The present combined model is a good blend of computational efficiency and accuracy in prediction of local transverse stresses. Plates with different stacking sequences are investigated for free edge stresses developed in the transverse direction under uniaxial in-plane load conditions.

Mixed Finite Element; Free edge stresses; Higher order theory; Principle of minimum potential energy; transition element; global-local analysis