Assessment of two methods for the accurate prediction of transverse stress distributions in laminates

Artikel i vetenskaplig tidskrift, 2016

A major challenge for crash failure analysis of laminates is to find a modelling approach which is both sufficiently accurate and computationally efficient. We suggest to adopt a traditional single-layer shell formulation due to its cost effectiveness. In this contribution, we have therefore investigated the potential of two different concepts for obtaining better prediction of the through-the-thickness distribution of the transverse stresses; a crucial issue since the accuracy for a single-layer approach in this respect is normally low. The first concept is a multiscale approach in which the macroscopic shell model is concurrently coupled to a mesoscopic 3D element representation of the heterogeneous material structure on the laminate level. The second concept is a stress recovery method based on integration of the 3D equilibrium equations, with additional smoothing of the in-plane stresses. The main conclusion drawn from the investigations is that, the adopted multiscale concept, although similar to what has been previously reported in the literature, is not a suitable approach to increase the level of accuracy of the predicted transverse stress distributions. However, we conclude that the proposed stress recovery method very well captures the through-the-thickness stress variations in our presented examples.