关键词: 复合材料层合板, 十字筋结构件, 弯曲失效, 数值分析, 粘接界面

Abstract: To investigate the failure behavior of glass fiber reinforced composite cross-rib structures subjected to in-plane bending loads, a combined experimental and numerical study was conducted. Three-point bending experiments are performed to characterize the progressive failure features of the structural components. Meanwhile, a multiscale numerical model incorporating the Hashin failure criterion and the cohesive zone model(CZM) is implemented in ABAQUS through the user subroutine VUMAT, enabling a systematic investigation of the overall load-carrying behavior and the failure mechanisms of key structural components.Experimental results indicate that the bending failure of the cross-rib structure exhibits a two-stage progressive damage characteristic. In the initial stage, fiber tensile fracture occurs in the central stiffener, accompanied by the initiation and propagation of interfacial debonding within the cross-rib components. The second stage is characterized by the global failure of the longitudinal rib. Numerical simulations successfully reproduce the overall trend of the load-displacement response and the key failure inflection points, showing strong agreement with experimental observations in terms of failure locations, dominant damage modes, and load-carrying capacity degradation mechanisms. Further numerical analysis reveals that interfacial damage in the L-shaped component of the cross-rib structure first initiates at the interface with the corner insert, subsequently propagates along the ply interfaces, and ultimately leads to the loss of bonding between the lower end of the L-shaped component and the main structure. Through combined experimental-numerical validation, this study provides a theoretical basis for the structural and interfacial optimization design of composite cross-rib structures.

Key words: composite laminates, cross-rib structural components, bending failure, numerical analysis, bonded interfaces