Analysis of after Impact Characteristics and Structural Optimization of CFRP Composite Plate

Low-velocity impact (LVI) damage on composite laminates may lead to a decrease of its load-carrying capacity, where different barely visible impact damages (BVID) would occur. The objectives of this study are (a) to identify the characteristics of carbon fiber reinforced polymer (CFRP) under LVI, (b) create a numerical model of the plate that is validated with the impact testing results, and (c) to perform size and shape optimization of the plate for improving the damage resistance. To achieve these goals, several composite laminate samples were fabricated. The LVI testing was performed on the samples with different impactors and varying impact energies. The X-Ray Micro-tomography technique was utilized to reveal the internal fiber damage and matrix damage of the impacted plate. Numerical models with nonlinear dynamic responses were built in ABAQUS and were compared with the LVI experiments data. The Hashin failure criteria were coupled with the model to predict possible damage existence, which gave a convincing match with the X-Ray imaging results. Further, the optimization tasks were created in MSC. PATRAN/NASTRAN to redesign the properties of thickness, ply orientation, and geometry of the plate to minimize the weight while abiding by the structural response constraints. Further, the potential of applying the OpenMDAO framework in nonlinear dynamic analysis was discussed.