螺栓断裂分离可靠性设计与试验验证

摘要

The reliability design and experimental verification for brittle fracture bolt which was used in shape memory alloy fracture mechanism under a certain load was conducted.The distribution of tensile strength and brittle characteristics was obtained via tension.The reliability design for brittle fracture bolt has been done using FOSM,and the stress-concentration-factor was taken into consideration.The reliability design was confirmed by using Monte Carlo method and function tests.An approximate normal-distribution curve has been found to suit the tensile strength of brittle steel.The material was characterized by using quasi-brittle property.Stress-concentration-factor and roughness on surface had a great impact on separation load in reliability design.The reliability experiment proved that the reliability design method of brittle fracture bolt was correct.%针对使用在SMA分离装置中的分离螺栓,在设计载荷下进行了结构脆性断裂分离的可靠度设计和试验验证.通过材料拉伸性能试验获取材料的强度性能分布,确定了材料的脆性特征.考虑应力集中系数的影响,应用一次二阶矩法对脆性断裂螺栓的结构进行了可靠度设计,并通过Monte Carlo随机抽样和可靠性试验验证了断裂螺栓结构设计的可靠性.结果表明:脆性断裂材料的抗拉强度服从正态分布,表现出沿晶断裂的准脆性力学特征;结构可靠性设计中切口的应力集中系数和加工粗糙度对分离载荷影响偏大;可靠性试验验证了脆性断裂螺栓的可靠性设计方法.