低速冲击下复合材料加筋板的损伤阻抗性能

为确定冲击能量、几何尺寸对低速冲击下复合材料加筋板损伤阻抗性能的影响,对3组工型加筋板进行了试验和数值模拟研究。通过落锤式低速冲击试验,得到了试验件的接触历程、凹坑深度和分层面积等损伤特征。基于引入纤维断裂损伤的各向异性弹塑性理论建立了有限元(FE)模型,对试验件凹坑深度进行了模拟预测,模拟结果与试验结果吻合较好。研究表明,复合材料加筋板凹坑深度随冲击能量的变化曲线存在拐点,拐点后表面冲击部位出现纤维断裂。随着冲击能量的增大,试验件的最大接触力不断增大,而分层起始载荷及分层面积则变化不大。含1.5 mm深凹坑试验件对应的冲击能量和最大接触力随筋条或蒙皮厚度的增大而不断增大,而分层起始载荷仅随蒙皮厚度的增大而增大。

Damage resistance property of stiffened composite panels under low-velocity impact

In order to study the effect of impact energy and structural geometry on damage resistance of stiffened composite panels under low-velocity impact, 3 groups of I-section stringer-stiffened composite panels were experimentally and numerically investigated. Drop weight low-velocity impact tests were conducted to capture the damage characteristics such as impact force histories, indentation depths and delamination areas. Finite element (FE) models were established based on an anisotropic elato-plastic theory incorporating fiber failure. Indentation depths of the specimens were simulated by the FE models. The simulated results are coordinated with the tested results very well. The results indicate that there is a knee point for the curve of impact energy and dent depth of stiffened composite panels. Some fiber breakage at the impact location on the surface of specimens can be found after the knee point occurs. The maximum impact force increases with the increasing impact energy, while the delamination initiation load and delamination area do not. The impact energy and the maximum impact force of specimens containing 1.5 mm indentation increase with the increasing thickness of skin or stiffener while the delamination initiation load only increases with the increasing thickness of skin.