Abstract In this paper, the low velocity impact (LVI) on a quasi-isotropic laminate [45/0/–45/90]3s (QIL) is studied to predict the deformation response and damage state of the laminate. This stacking of a QIL is a benchmark case that results in a “rotating-fan” pattern of delamination damage due to the impact. Drop-tower tests were performed with an impact energy of 25 J and an impactor mass of 7.5 kg. 3D digital image correlation (3D DIC) was carried out to measure the in situ deformation of the laminate. Non-destructive inspection (NDI) including ultrasound C-scanning and X-ray micro computed tomography (micro-CT) were done to characterize the overall damage footprint and the internal detailed damage morphology. The computational model is an extension and refinement of the model developed in Refs. [74] , [76] . Enhanced Schapery Theory (EST) is used as the constitutive model and implemented with a user material subroutine in the commercial code Abaqus. The EST uses Schapery theory for pre-peak damage and the crack band model for post peak failure. The major contributions reported in this paper are as follows; in the experimental study, the damage mechanisms have been illustrated with high-resolution micro-CT scanning, while in the numerical study, the “rotating-fan” pattern, damage-free cone and damage modes interaction have been accurately and efficiently captured with a uniform, non-fiber-aligned mesh.

中文翻译：

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使用 EST 预测准各向同性层压板的低速冲击损伤

摘要 在本文中，研究了准各向同性层压板 [45/0/–45/90]3s (QIL) 上的低速冲击 (LVI)，以预测层压板的变形响应和损坏状态。QIL 的这种堆叠是一个基准案例，它会导致由于冲击而导致分层损坏的“旋转扇形”模式。使用 25 J 的冲击能量和 7.5 kg 的冲击器质量进行落塔试验。进行 3D 数字图像相关 (3D DIC) 以测量层压板的原位变形。进行了包括超声 C 扫描和 X 射线显微计算机断层扫描 (micro-CT) 在内的无损检测 (NDI)，以表征整体损伤足迹和内部详细的损伤形态。计算模型是参考文献中开发的模型的扩展和改进。[74]，[76]。增强型 Schapery 理论 (EST) 用作本构模型，并通过商业代码 Abaqus 中的用户材料子程序实现。EST 使用 Schapery 理论进行峰值前损坏，使用裂纹带模型进行峰值后故障。本文报告的主要贡献如下；在实验研究中，损伤机制已通过高分辨率显微 CT 扫描说明，而在数值研究中，“旋转扇”模式、无损伤锥体和损伤模式相互作用已被准确有效地捕捉到均匀的、非纤维对齐的网格。本文报告的主要贡献如下；在实验研究中，损伤机制已通过高分辨率显微 CT 扫描说明，而在数值研究中，“旋转扇”模式、无损伤锥体和损伤模式相互作用已被准确有效地捕捉到均匀的、非纤维对齐的网格。本文报告的主要贡献如下；在实验研究中，损伤机制已通过高分辨率显微 CT 扫描说明，而在数值研究中，“旋转扇”模式、无损伤锥体和损伤模式相互作用已被准确有效地捕捉到均匀的、非纤维对齐的网格。