APPLICATION OF THE REFINED ZIGZAG THEORY TO DAMAGE MODELLING OF LAMINATED COMPOSITES
Rainer Groh, NIA Visiting Researcher, University of Bristol
March 23, 2015, 2:00 pm, NASA Langley, Bldg 1148, Rm 242
Abstract:
The Refined Zigzag Theory (RZT) is an equivalent single-layer theory developed by Dr. Alex Tessler and co-workers for the structural analysis of highly heterogeneous composite laminates and sandwich beam, plate, and shell structures. The theory computes accurate displacement fields and full three-dimensional (3-D) stress fields, even when individual layers in a laminate have properties that vary by orders of magnitude. Furthermore, this is achieved at a fraction of the cost of full 3-D finite analysis due to the 2-D equivalent single-layer formulation. To date, the accuracy of the theory has been validated against 3-D elasticity solutions for a variety of applications using exact elasticity solutions, finite element, and other numerical techniques. The aim of this research effort is to explore the possibilities of RZT in damage modelling of layered composite structures. Applications for modelling intra-ply damage using continuum damage models and inter-ply delimitation damage using cohesive zone formulations is discussed.
Biography:
Rainer Groh is a final year PhD student supervised by Prof. Paul Weaver at the Advanced Composites Centre for Innovation and Science, University of Bristol, UK. His research is focused on deriving numerically efficient computational models and applying these to predict damage and loss of stability in thin aerospace structures. The main aim of the research is to optimize composite laminates with curvilinear fiber paths in order to improve the buckling and post-buckling behavior of thin plates and shells. Current work at NASA Langley aims to extend the computational models to damage modelling of laminated composites. To date, Rainer has authored 4 journal papers and 4 conference papers.