Formability of a continuous fiber-reinforced material is known to be influenced by its intraply shear behavior. This study investigates a 2 × 2 twill weave carbon fabric and the corresponding vinyl-based thermoset prepreg developed for press-cured structural parts. Intraply shear tests of bias-extension and picture-frame were conducted for a range of industrial-relevant processing conditions of temperature and shear rate. The dry fabric was characterized similar to the prepreg to isolate the influence of semi-cured resin on the woven prepreg fabric formability in shear. The shear deformation behavior of the prepreg, usually dependent on the fabric architecture, is found to be controlled by the state of the resin. The results clearly show the significance of the choice of process parameters on the prepreg shear behavior. It is demonstrated that preheating the prepreg to temperatures considerably lower than required to initiate cure can make the shear formability of the woven prepreg equivalent to the constituent (dry) reinforcement fabric. The actual shear angle measurement during the bias-extension tests demonstrates the level of inter-tow slippage for the prepreg fabric at relatively elevated temperatures. The comparison of normalized shear data from the two test methods helps to determine the improved procedure for prepreg fabric testing.

已知连续纤维增强材料的成形性受其内部剪切行为的影响。这项研究调查了一种2×2斜纹编织碳纤维织物和相应的基于乙烯基的热固性预浸料，这些预浸料是为压固化的结构零件开发的。针对温度和剪切速率的一系列与工业相关的加工条件，进行了偏差延伸和像框的内部剪切测试。干燥织物的特性类似于预浸料，以隔离半固化树脂对编织预浸料的剪切成形性的影响。发现预浸料的剪切变形行为通常取决于织物结构，这是由树脂的状态控制的。结果清楚地表明选择工艺参数对预浸料的剪切行为的重要性。已经证明，将预浸料坯预热到比引发固化所需的温度低得多的温度，可以使织造的预浸料坯的剪切成形性等同于组成（干）增强织物。在偏斜延伸试验期间的实际剪切角测量结果表明，预浸料织物在相对较高的温度下丝束间的滑动程度。来自两种测试方法的标准化剪切数据的比较有助于确定预浸料织物测试的改进程序。在偏斜延伸试验期间的实际剪切角测量结果表明，预浸料织物在相对较高的温度下丝束间的滑动程度。来自两种测试方法的标准化剪切数据的比较有助于确定预浸料织物测试的改进程序。在偏斜延伸试验期间的实际剪切角测量结果表明，预浸料织物在相对较高的温度下丝束间的滑动程度。来自两种测试方法的标准化剪切数据的比较有助于确定预浸料织物测试的改进程序。