论文部分内容阅读
针对纤维束增强复合材料,提出了双层次随机扩大临界核模型。以复合材料制造工艺为基础建立了纤维间距和纤维束中纤维根数的计算模型,将复合材料中的纤维分为2个层次:纤维束和纤维束群,并提出父核和子核的概念对临界核的构成进行了区分,用Beyerlein公式计算纤维束群中纤维束相继失效引起的纤维束的平均应力集中因子,用Sivasambu公式来计算纤维束中纤维相继断裂造成的纤维的应力集中因子。然后,以纤维断裂蔓延的主要模式为基础,将逐渐增大的无效长度引入纤维束内部,根据统计学理论推导相应的复合材料破坏概率计算公式。编制了相关程序,通过该程序分别预测了S玻纤、E玻纤、玄武岩纤维无捻单向纤维布增强复合材料试件的拉伸强度。对3种复合材料板进行了拉伸强度及基体的拉伸和剪切实验,并对比了预测结果与实验结果。研究结果显示,直接将实验对象的材料、几何参数代入就能得到与实验结果吻合的预测结果。
Aiming at the fiber bundle reinforced composite material, a two-level stochastic expanded critical kernel model is proposed. Based on the composite manufacturing process, the calculation models of the fiber spacing and the number of fibers in the fiber bundle are established. The fibers in the composite material are divided into two levels: the fiber bundle and the fiber bundle group, and the concept pair of parent and daughter nuclei The composition of the critical nuclei is distinguished. The Beyerlein formula is used to calculate the average stress concentration factor of the fiber bundles caused by the failure of the fiber bundles in the fiber bundle group. The stress concentration factor of the fibers caused by the successive fiber breakage in the fiber bundles is calculated by the Sivasambu formula. Then, based on the main mode of fiber breakage propagation, the gradually increasing ineffective length was introduced into the fiber bundle, and the formula for calculating the failure probability of composite material was deduced according to the statistical theory. The related program was prepared, through which the tensile strength of S glass fiber, E glass fiber, basalt fiber twisting unidirectional fiber cloth reinforced composite material specimen were respectively predicted. Tensile strength and tensile and shear tests of three kinds of composite plates were carried out. The predictions and experimental results were compared. The results show that the direct fit of the material and geometric parameters of the experimental object can get the predicted results in good agreement with the experimental results.