Abstract In this work the possibility to reverse engineer the transverse isotropic carbon fibre properties from the 3D homogenized elastic tensor of the UD ply for the prediction of woven ply properties is explored. Ultrasonic insonification is used to measure the propagation velocity of both the longitudinally and transversally polarized bulk waves at various symmetry planes of a unidirectional (UD) Carbon/Epoxy laminate. These velocities and the samples' dimensions and density are combined to obtain the full 3D orthotropic stiffness tensor of the ply. The properties are subsequently used to reverse engineer the stiffness tensor, assumed to be transversely isotropic, of the carbon fibres. To this end, four micro-scale homogenization methods are explored: 2 analytical models (Mori-Tanaka and Mori-Tanaka-Lielens), 1 semi-empirical (Chamis) and 1 finite-element (FE) homogenization (randomly distributed fibres in a Representative Volume Element). Next, the identified fibre properties are used to predict the elastic parameters of UD plies with multiple fibre volume fractions. These are then used to model the fibre bundles (yarns) in a meso-scale FE model of a plain woven carbon/epoxy material. Finally, the predicted elastic response of the woven carbon/epoxy is compared to the experimentally obtained elastic stiffness tensor. The predicted and measured properties are in good agreement. Some discrepancy exists between the ultrasonically measured value of the Poisson's ratio and the predicted value. Nonetheless, it is shown that virtual identification and prediction of mechanical properties for woven plies is feasible.

中文翻译：

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使用超声波识别识别横向各向同性碳纤维特性和预测编织弹性特性的多尺度方法

摘要 在这项工作中，探索了从 UD 层的 3D 均质弹性张量逆向工程横向各向同性碳纤维性能以预测编织层性能的可能性。超声波超声波用于测量单向 (UD) 碳/环氧树脂层压板的各种对称平面上的纵向和横向极化体波的传播速度。这些速度与样品的尺寸和密度相结合，以获得层的完整 3D 正交各向异性刚度张量。这些特性随后用于对碳纤维的刚度张量进行逆向工程，假定为横向各向同性。为此，探索了四种微尺度均质化方法：2 个分析模型（Mori-Tanaka 和 Mori-Tanaka-Lielens），1 个半经验 (Chamis) 和 1 个有限元 (FE) 均质化（代表性体积元素中随机分布的纤维）。接下来，确定的纤维特性用于预测具有多种纤维体积分数的 UD 层的弹性参数。然后将它们用于在平纹碳纤维/环氧树脂材料的中尺度有限元模型中对纤维束（纱线）进行建模。最后，将编织碳/环氧树脂的预测弹性响应与实验获得的弹性刚度张量进行比较。预测和测量的特性非常一致。泊松比的超声波测量值与预测值之间存在一些差异。尽管如此，它表明编织层的机械性能的虚拟识别和预测是可行的。