Damage propagation in CFRP laminates subjected to low velocity impact and static indentation
Damage propagation in CFRP laminates subjected to low velocity impact and static indentation
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DOI：
10.1163/156855107779755318
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发表时间：
2007-01-01
影响因子：
2.9
通讯作者：
Ishikawa, Takashi
中科院分区：
文献类型：
--
作者：
Aoki, Yuichiro;Suemasu, Hiroshi;Ishikawa, Takashi
本文描述了正交铺层CFRP层板[0（2）/90（2）]（2S）在面外载荷作用下的损伤累积机理。进行了落锤冲击和静态压痕试验，并通过超声C扫描和光学显微镜观察诱导损伤。两种试验给出的损伤模式、尺寸和载荷-变形历史的结果基本相同。首先，在底部0度层中发生裂纹，伴随着由弯曲应力引起的沿着裂纹的一些分层。随着试样与压头间接触力的减小，中间90度层出现横向裂纹。在撞击点附近测量的局部应变表明，应力状态从弯曲主导状态转变为面内拉伸主导状态。采用内聚界面单元模拟了静态压痕作用下多个分层和横向裂纹的扩展。两种类型的分析模型被认为是，一个与多个脱层和其他的多个脱层和横向裂纹。对于只有多个脱层的模型，得到的损伤与实验得到的损伤有很大的不同。然而，从脱层和横向裂纹的模型得到的结果很好地解释了在实验中得到的损伤的特点。横向裂纹的存在是形成特征冲击损伤的必要条件。
This paper describes a damage accumulation mechanism in cross-ply CFRP laminates [0(2)/90(2)](2S) subjected to out-of-plane loading. Drop-weight impact and static indentation tests were carried out, and induced damage was observed by ultrasonic C-scan and an optical microscope. Both tests gave essentially the same results for damage modes, sizes, and load-deformation history. First, a crack occurred in the bottom 0 degrees layer accompanying some delamination along the crack caused by bending stress. Then, transverse cracks occurred in the middle 90 degrees layer with decreasing contact force between the specimen and the indenter. Measured local strains near the impact point showed that the stress state changed from a bending dominant state to an in-plane tensile dominant state. A cohesive interface element was used to simulate the propagation of multiple delaminations and transverse cracks under static indentation. Two types of analytical models are considered, one with multiple delaminations and the other with both multiple delaminations and transverse cracks. The damage obtained for the model with only multiple delaminations was quite different from that obtained from the experiment. However, the results obtained from the model with both delaminations and transverse cracks well explain the characteristics of the damage obtained in the experiment. The existence of the transverse cracks is essential to form the characteristic impact damage.