An Improved Design Methodology for Modeling Thick-Section Composite Structures Using a Multiscale Approach

Report No. ARL-TR-6180
Authors: Jeffrey M. Staniszewski, Travis A. Bogetti, Michael Keefe, and Brian Powers
Date/Pages: September 2012; 112 pages
Abstract: Material nonlinearity and progressive ply failure are important considerations in the finite element modeling of thick-section composite structures. LAMPATNL uses a method to model the material nonlinearity and progressive ply failure of composite laminates using finite element software without explicitly simulating individual plies. Improvements to LAMPATNL are documented and discussed in this report. Also, LAMPATNL is validated against both the linear and nonlinear material point models. In this work, a standardized process for designing composite structures with LAMPATNL using newly formulated output parameters, stiffness ratios, to analyze the nonlinear response and progressive failure of the composite structure is developed. These new parameters greatly improve the visualization of critical design information of the structure. Two case studies, an open-hole sample under multi-axial loading and a compressive shear sample, are evaluated using the design methodology. Coupling LAMPATNL with a design methodology and new stiffness ratio parameters demonstrates the utility of progressive failure and nonlinear analysis when applied to composite structures. The straightforward visualization of critical design information creates a unique approach to analyzing the design of thick section composites. This methodology represents a unique contribution to the modeling of composite structures that is not matched by any current composite model.
Distribution: Approved for public release
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Last Update / Reviewed: September 1, 2012