Data from: An experimental study on the manufacture and characterisation of in-plane fibre-waviness defects in composites

A new method has been developed for creating localised in-plane fibre-waviness in composite coupons and used to create a large batch of specimens. This method could be used by manufacturers to experimentally explore the effect of fibre-waviness on composite structures both directly and indirectly to develop and validate computational models. The specimens were assessed using ultrasound, digital image correlation and a novel inspection technique capable of measuring residual strain fields. To explore how the defect affects the performance of composite structures, the specimens were then loaded to failure. Predictions of remnant strength were made using a simple ultrasound damage metric and a new residual strain-based damage metric. The predictions made using residual strain measurements were found to be substantially more effective at characterising ultimate strength than ultrasound measurements. This suggests that residual strains have a significant effect on the failure of laminates containing fibre-waviness and that these strains could be incorporated into computational models to improve their ability to simulate the defect.

本研究开发了一种可在复合材料试片（composite coupon）中制备局部面内纤维波纹缺陷（localised in-plane fibre-waviness）的新型方法，并利用该方法制备了大批量试样。该方法可供制造商通过直接与间接实验方式，探究纤维波纹对复合材料结构的作用效应，从而开发并验证相关计算模型。研究人员采用超声检测（ultrasound）、数字图像相关法（digital image correlation, DIC）以及一种可测量残余应变场（residual strain fields）的新型检测技术，对所制备的试样完成了表征评估。为明确该缺陷对复合材料结构力学性能的影响，研究人员对试样开展了加载至失效的力学测试。研究人员分别基于简易超声损伤指标与新型残余应变基损伤指标，对试样的剩余强度（remnant strength）进行了预测。研究结果表明，基于残余应变测量得到的预测结果，相较超声测量方法，在表征层合板（laminates）极限强度（ultimate strength）方面效果更为优异。该发现证实，残余应变对含纤维波纹缺陷的层合板失效过程具有显著影响，且可将此类应变纳入计算模型，以提升其模拟该类缺陷的能力。