Abstract Carbon fiber reinforced plastics (CFRPs) are attracting growing attention in industry because of their enhanced properties. Preforming of thermoset carbon fiber prepregs is one of the most common production techniques of CFRPs. To simulate preforming, several computational methods have been developed. Most of these methods, however, obtain the material properties directly from experiments such as uniaxial tension and bias-extension where the coupling effect between tension and shear is not considered. Neglecting this coupling effect deteriorates the prediction accuracy of simulations. To address this issue, we develop a Bayesian model calibration and material characterization approach in a multiscale finite element preforming simulation framework that utilizes mesoscopic representative volume element (RVE) to account for the tension-shear coupling. A new geometric modeling technique is first proposed to generate the RVE corresponding to the close-packed uncured prepreg. This RVE model is then calibrated with a modular Bayesian approach to estimate the yarn properties, test its potential biases against the experiments, and fit a stress emulator. The predictive capability of this multiscale approach is further demonstrated by employing the stress emulator in the macroscale preforming simulation which shows that this approach can provide accurate predictions.

中文翻译：

---

用于具有拉剪耦合的多尺度预浸料坯预成型模拟的数值贝叶斯校准表征方法

摘要 碳纤维增强塑料（CFRPs）由于其增强的性能而在工业界引起越来越多的关注。热固性碳纤维预浸料的预成型是 CFRP 最常见的生产技术之一。为了模拟预成型，已经开发了几种计算方法。然而，这些方法中的大多数直接从单轴拉伸和偏置延伸等实验中获得材料特性，其中不考虑拉伸和剪切之间的耦合效应。忽略这种耦合效应会降低模拟的预测精度。为了解决这个问题，我们在多尺度有限元预成形模拟框架中开发了贝叶斯模型校准和材料表征方法，该框架利用细观代表性体积元素 (RVE) 来解释拉剪耦合。首次提出了一种新的几何建模技术来生成对应于密堆积未固化预浸料的 RVE。然后使用模块化贝叶斯方法校准该 RVE 模型，以估计纱线特性，根据实验测试其潜在偏差，并安装应力模拟器。通过在宏观预成型模拟中使用应力仿真器进一步证明了这种多尺度方法的预测能力，这表明这种方法可以提供准确的预测。首次提出了一种新的几何建模技术来生成对应于密堆积未固化预浸料的 RVE。然后使用模块化贝叶斯方法校准该 RVE 模型，以估计纱线特性，根据实验测试其潜在偏差，并安装应力模拟器。通过在宏观预成型模拟中使用应力仿真器进一步证明了这种多尺度方法的预测能力，这表明这种方法可以提供准确的预测。首次提出了一种新的几何建模技术来生成对应于密堆积未固化预浸料的 RVE。然后使用模块化贝叶斯方法校准该 RVE 模型，以估计纱线特性，根据实验测试其潜在偏差，并安装应力模拟器。通过在宏观预成型模拟中使用应力仿真器进一步证明了这种多尺度方法的预测能力，这表明这种方法可以提供准确的预测。