Abstract This paper presents a novel progressive failure model for the 3D simulations of pultruded FRP structures which allows the modelling of the laminates as a homogeneous material. The failure initiation model proposed requires only the strength in each direction as input, combining them to retrieve in-plane and out-of-plane failure indexes. The damage propagation model can be divided in two main stages: (i) damage progression and (ii) constant stress beyond a limit strain. The former stage uses the in-plane and out-of-plane failure indexes to determine the damage progression, using different parameters in each direction to account for the different damage responses, while the latter is characterized by a constant stress after a limit strain is reached, also different for each direction. FE models were developed with the proposed damage propagation model, requiring as input the strengths obtained from standardize experimental material coupon testing, the results of which, namely the load/stress vs. displacement/strain curves, are used to calibrate all the parameters needed to established the model. The results show that the proposed damage propagation model, using a homogenized material, is well able to predict the experimental behaviour even for very complex cases such as interlaminar shear tests. Furthermore, in a companion paper the accuracy and limitations of the model are further assessed in the simulation of transverse compact tension and web-crippling tests.

中文翻译：

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准正交各向异性拉挤玻璃钢结构的新型渐进破坏模型：参数的公式化和校准（第一部分）

摘要 本文提出了一种新的渐进式失效模型，用于拉挤 FRP 结构的 3D 模拟，该模型允许将层压板建模为均质材料。提出的失效起始模型只需要每个方向的强度作为输入，将它们结合起来检索平面内和平面外的失效指标。损伤传播模型可以分为两个主要阶段：（i）损伤进展和（ii）超过极限应变的恒定应力。前一阶段使用面内和面外失效指标来确定损伤进程，在每个方向使用不同的参数来解释不同的损伤响应，而后者的特点是极限应变后应力恒定为到达，每个方向也不同。有限元模型是使用建议的损伤传播模型开发的，需要从标准化实验材料试样测试中获得的强度作为输入，其结果，即载荷/应力与位移/应变曲线，用于校准所有需要的参数建立了模型。结果表明，所提出的损伤传播模型使用均质材料，即使在非常复杂的情况下（如层间剪切试验）也能很好地预测实验行为。此外，在一篇配套论文中，模型的准确性和局限性在横向紧凑张力和卷筒纸损坏测试的模拟中得到了进一步评估。位移/应变曲线，用于校准建立模型所需的所有参数。结果表明，所提出的损伤传播模型使用均质材料，即使在非常复杂的情况下（如层间剪切试验）也能很好地预测实验行为。此外，在一篇配套论文中，模型的准确性和局限性在横向紧凑张力和卷筒纸损坏测试的模拟中得到了进一步评估。位移/应变曲线，用于校准建立模型所需的所有参数。结果表明，所提出的损伤传播模型使用均质材料，即使在非常复杂的情况下（如层间剪切试验）也能很好地预测实验行为。此外，在一篇配套论文中，模型的准确性和局限性在横向紧凑张力和卷筒纸损坏测试的模拟中得到了进一步评估。