含初始脱粘损伤的复合材料加筋板压缩性能评估OA

This study combines experimental and numerical approaches to investigate the effects of initial debonding defects at the stringer-skin interface on the compressive behavior of composite stiffened panels.Digital Image Correla-tion(DIC)and strain gauge measurements were employed to characterize the buckling and post-buckling behavior.The experimental results demonstrate that while the initial debonding has limited influence on the buckling load,it in-duces buckling mode transition during compression and causes premature interfacial failure near the pre-existing debonded region,leading to a significant reduction(up to 18.6%)in structural load-bearing capacity.An innovative cohesive zone modeling approach was developed based on an interface failure criterion that accounts for the inhibition of shear failure due to out-of-plane compressive stress,where the intact interface and pre-debonded region were simu-lated using cohesive elements with a bilinear damage constitutive model and contact constitutive model,respectively.A progressive damage finite element model was subsequently established,successfully reproducing the post-buckling failure process.The numerical predictions show excellent agreement with experimental data,with buckling load errors below 4%and failure load errors within 7%,while accurately capturing the buckling modes transition and failure pro-gression.Parametric studies were conducted to evaluate the effects of debonding size and location on the compres-sive post-buckling performance.The findings provide valuable references for damage-tolerant design of composite stiff-ened structures.