Abstract Fiber-reinforced polymers combine the aspects of stiff fibers and light polymer matrix. The arrangement of fibers on the microstructural level significantly affects the mechanical properties on the macroscopic scale, such as stiffness and fracture toughness. Micro-computed tomography systems (μCT) enables a detailed volumetric view into microstructures in a none-destructive way. By performing mechanical test inside a μCT system, the effects of mechanical load onto the microstructure, such as damage initiation and propagation are observed in-situ. Since cyclic load is a common use case for many components, fatigue and cycle load tests are essential for material characterizing. In this contribution, the authors introduce an in-situ μCT setup for cyclic load tests. The test device is designed to generate high-resolution images, in order to observe cracks through different propagation stages. In addition, cracks are three-dimensionally segmented and a crack volume fraction definition is introduced. The presented in-situ test setup and crack characterization method are demonstrated on sheet molding compound specimen, a glass-fiber reinforced thermosetting material system.

中文翻译：

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使用显微计算机断层扫描对不连续纤维增强复合材料进行裂纹表征：循环原位测试、裂纹分割和裂纹体积分数

摘要 纤维增强聚合物结合了刚性纤维和轻质聚合物基体的特性。微观结构水平上的纤维排列显着影响宏观尺度上的机械性能，如刚度和断裂韧性。微型计算机断层扫描系统 (μCT) 能够以非破坏性的方式对微观结构进行详细的立体观察。通过在 μCT 系统内部进行机械测试，可以原位观察机械载荷对微观结构的影响，例如损伤的发生和扩展。由于循环载荷是许多组件的常见用例，因此疲劳和循环载荷测试对于材料表征至关重要。在这篇文章中，作者介绍了用于循环负载测试的原位 μCT 设置。测试设备旨在生成高分辨率图像，以观察裂纹通过不同的扩展阶段。此外，裂纹被三维分割，并引入了裂纹体积分数的定义。所提出的原位测试装置和裂纹表征方法在片状模塑料样品（一种玻璃纤维增​​强热固性材料系统）上进行了演示。