Authors
Michel van Tooren, Ali Elham, Ramy Harik
Conference
16th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, (p. 2488). Dallas, Texas, United States.
Abstract
This paper presents a framework for the design of variable stiffness fiber composite panels subject to multiple load cases, each case a combination of tension and shear. The framework consists of a finite element (FE) solver, an optimizer, a module that controls the link between design variables and the stiffness matrix in the FE module, and a postprocessor that translates the theoretical optimal result from the optimizer into discrete tow paths for each ply. The dual mesh formulation of the design variables using a manufacturing mesh separate from the FE mesh limits the number of design variables while preserving smoothness and allows easy specification of manufacturing constraints enforced by the envisioned fiber steering process, for example the minimum course radius to prevent tow buckling. It also allows the incorporation of constraints related to fusion bonding techniques for continuous carbon fiber reinforced thermoplastic composites based on induction heating which require the generation of eddy currents and therefore constrain the fiber orientations and stacking sequence. The framework is intended for inclusion in an MDO based aircraft wing weight estimation tool in which it is combined with aerodynamic analysis and optimization. Results obtained with the framework show the structural benefit of using variable stiffness also in case of multiple load cases. The design variable formulation leads to acceptable calculation time while preserving accuracy and smoothness of the solution. Separation of optimizer and tow path planner allows multiple practical interpretations of the theoretical optimization result. This preserves the influence of the manufacturing engineer on the practical panel lay-up.
Citation
Michel van Tooren, Ali Elham, & Ramy Harik. (June 2015). Optimal Variable Stiffness Distribution for a Composite Plate with a Row of Holes Subjected to Tension/Shear Load Cases. 16th AIAA/ISSMO Multidisciplinary Analysis and Optimization Conference, (p. 2488). Dallas, Texas, United States. doi:https://doi.org/10.2514/6.2015-2488.
Link: https://arc.aiaa.org/doi/pdf/10.2514/6.2015-2488
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