L-shaped stiffened composite panels provide an efficient structure for engineering applications. However, they often produce delamination in the preparation and service process due to a series of factors. To study the effect of different types of delamination on the compressive strength of stiffened composite panels, ABAQUS finite element software was used in combine with the progressive damage subroutine user-defined field variable (USDFLD), and the finite element model was established based on cohesive theory to realize the prediction of the progressive failure process and strength of the stiffened composite panels. The results showed that the delamination of a stringer had a greater impact on the strength of the stiffened composite panels than did the debonding between the skin panel and a stringer and the delamination of the skin panel. The debonding delamination and delamination of a stringer exhibited delamination growth near the damage position during static compression, but delamination of the skin panel exhibited no delamination growth. The experimental results were in good agreement with the finite element simulation results, which verified the validity of the finite element model.

中文翻译：

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压缩载荷下分层加筋复合板的试验和数值分析

L 形加筋复合板为工程应用提供了有效的结构。然而，由于一系列因素，它们在制备和使用过程中往往会产生分层。为研究不同类型分层对加筋复合板抗压强度的影响，采用ABAQUS有限元软件，结合渐进式损伤子程序用户定义场变量（USDFLD），建立基于内聚力的有限元模型。理论来实现对加筋复合板渐进破坏过程和强度的预测。结果表明，纵梁脱层对加筋复合板强度的影响大于蒙皮板与纵梁之间的脱粘和蒙皮板脱层。在静态压缩过程中，纵梁的脱粘分层和分层在损坏位置附近表现出分层增长，但蒙皮面板的分层没有表现出分层增长。实验结果与有限元仿真结果吻合较好，验证了有限元模型的有效性。