Multiscale Analysis of Modal Characteristics for L‐Shaped <scp>CFRP</scp> Laminates With Voids

ABSTRACT This study for the first time develops a hybrid stochastic multiscale modeling (HSMM) framework to reveal the impact of void defects on the modal characteristics of geometrically complex carbon fiber‐reinforced polymer (CFRP) laminates. To this end, voids within the composite are statistically characterized based on optical microscopy observations and used to construct high‐fidelity representative volume elements (RVEs) and representative defective volumes (RDVs). These microstructural models are analyzed using micromechanics‐based finite element (FE) simulations to obtain homogenized stiffness parameters. Subsequently, a region‐partitioned modeling strategy is implemented to capture spatially varying porosity effects within L‐shaped CFRP structures. The proposed HSMM framework is validated through a cross‐comparison with conventional FEM predictions and experimental modal analysis (EMA). The results confirm that the model accurately predicts mode‐specific frequency shifts induced by void clustering. The developed framework offers a promising tool for virtual evaluation and performance‐informed design of vibration‐sensitive composite structures under manufacturing‐induced defects.