ABSTRACT Discontinuous prepreg platelet based carbon fibre sheet moulding compound (CF-SMC) materials offer huge potential for lightweight applications in the automotive industry. The composition of these materials and the flow behaviour during compression moulding result in a complex stochastic mesostructure, which presents a challenge in the modelling of the mechanical behaviour. The objective of the current work is to use the information obtained from multiscale X-ray computed tomography (XCT) scans to generate full-scale three-dimensional finite element models of tensile coupon specimens for the prediction of the elastic modulus. The models incorporate the stochastic distribution and discontinuous nature of the prepreg platelets. Defects such as porosity, resin-rich areas and fibre waviness can be observed by means of XCT. Porosity is found to be below 0.0076 vol.% and thus negligible. An average volume fraction of 6.48 vol.% of interlaminar resin-rich areas is considered in the mesostructural simulations. The predicted values of the tensile modulus are validated by experimental tensile tests on basis of a large series of specimens. The statistical analysis of variance methodology is employed to reach conclusive validation. The inherent stochasticity of prepreg platelet based CF-SMC materials is well captured with the proposed mesostructural simulation approach and the variability in their mechanical properties is accurately predicted.

中文翻译：

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基于 X 射线计算机断层扫描的不连续预浸料片基碳纤维板模塑料的细观结构模拟

摘要 不连续预浸料片基碳纤维片状模塑料 (CF-SMC) 材料为汽车行业的轻量化应用提供了巨大的潜力。这些材料的成分和压缩成型过程中的流动行为导致复杂的随机细观结构，这对机械行为的建模提出了挑战。当前工作的目标是使用从多尺度 X 射线计算机断层扫描 (XCT) 扫描获得的信息来生成拉伸试样试样的全尺寸三维有限元模型，以预测弹性模量。这些模型结合了预浸料片的随机分布和不连续性质。通过 XCT 可以观察到诸如孔隙率、富含树脂的区域和纤维波纹等缺陷。发现孔隙率低于 0.0076 vol.%，因此可以忽略不计。在细观结构模拟中考虑了 6.48 vol.% 的层间富含树脂区域的平均体积分数。拉伸模量的预测值通过基于大量试样的实验拉伸试验得到验证。方差方法的统计分析被用来达到结论性的验证。所提出的细观结构模拟方法很好地捕捉了基于预浸料片的 CF-SMC 材料的固有随机性，并准确预测了其机械性能的可变性。拉伸模量的预测值通过基于大量试样的实验拉伸试验得到验证。方差方法的统计分析被用来达到结论性的验证。所提出的细观结构模拟方法很好地捕捉了基于预浸料片的 CF-SMC 材料的固有随机性，并准确预测了其机械性能的可变性。拉伸模量的预测值通过基于大量试样的实验拉伸试验得到验证。方差方法的统计分析被用来达到结论性的验证。所提出的细观结构模拟方法很好地捕捉了基于预浸料片的 CF-SMC 材料的固有随机性，并准确预测了其机械性能的可变性。