平纹编织复合材料加筋壁板低速冲击及冲击后压缩性能多尺度分析

Multiscale modeling of the low-velocity impact and compression after impact behaviors of rib-stiffened plain woven composites

该文通过构建平纹编织复合材料(plain woven composites,PWC)的微/细/宏观多尺度模型,对复合材料T型和工型加筋壁板的低速冲击(low-velocity impact,LVI)和冲击后压缩(compression after impact,CAI)性能进行分析。根据PWC内部结构特征,构建微观和细观代表性体积单元(representative volume element,RVE)模型,通过施加不同的载荷条件,预测其等效力学参数。同时,基于局部均匀化方法,将细观RVE模型转化为包含0°和90°子胞的等效交叉层合板(equivalent cross-ply laminate,ECPL)胞元。通过ECPL胞元建立PWC加筋壁板的宏观分析模型,并进行LVI和CAI性能分析。首先进行了能量为8 J、10 J和12 J的LVI试验和多尺度模拟,研究了PWC加筋壁板在LVI载荷下的力学行为。随后,对不同能量冲击后的加筋壁板进行CAI试验和数值模拟,研究其冲击后压缩剩余力学性能和损伤行为。最后,通过对比分析不同能量冲击下的LVI和CAI试验和预测结果,发现多尺度模型对加筋壁板力学性能的预测误差均小于6%,验证了该多尺度模型的有效性。试验和预测结果表明,在CAI载荷作用下,PWC加筋壁板的蒙皮部分沿着冲击损伤的位置发生完全断裂,其中,纤维断裂和层间分层成为PWC加筋壁板的主要损伤形式。此外,工型加筋壁板表现出更好的抵抗压缩强度衰减能力。

This study proposes multiscale models to investigate the low-velocity impact(LVI) and compression after impact(CAI) behaviors of plain woven composite(PWC) panels stiffened by T-and I-shaped ribs.Representative volume elements(RVEs) were constructed at the microscale and mesoscale to compute the effective properties of carbon-fiber yarns and PWC.Besides,to improve the computational efficiency without sacrificing computational accuracy,an equivalent cross-ply laminate(ECPL) cell was introduced to represent the woven architecture using a local homogenization approach.Multiscale models of PWC panels stiffened by T-and I-shaped ribs were constructed to investigate the mechanical behavior and damage mechanisms.Initially,experimental and numerical tests with 8 J,10 J and 12 J impact energies were performed to examine the LVI behavior of PWC rib-stiffened panels.Subsequently,the post-impact compressive behavior and properties were assessed by experimental and numerical CAI tests on these impacted panels.The dissimilarities between the experimental and numerical results are less than 6%,confirming the reliability of the proposed multiscale models.Moreover,the panels stiffened by an I-shaped rib were found to exhibit better resistance to the compressive strength reduction due to LVI events.Besides,the primary damage modes of rib-stiffened PWC panels under LVI loads are matrix cracking and fiber breakage.In CAI cases,the existing impact damages are prone to lead to severe delamination within the rib-stiffened panels and accelerate final failure.