机械热弱链设计及其安全性评估方法研究

Research on Design and Safety Evaluation Method of the Mechanical-Thermal Weak-Link

机械热弱链结构用于异常高温火烧环境下,以可预见的方式先于强链环节(如火工品)发生不可恢复的失效,从而起到预期的安全保护功能。定义弱链先于强链失效为设计有效,系统安全;定义强链先于弱链失效为设计失败,系统安全失效。由于强/弱链环节的失效温度存在一定的分散性,故含弱链设计系统存在安全失效概率。为获得系统的安全失效概率,使用了概率论方法进行不确定性的处理,在计算上,使用了积分法和随机模拟方法。计算实例表明,积分法与随机模拟方法获得的安全性评估结果一致。

In an abnormal high-temperature fire environment,a mechanical-thermal weak-link structure is used to predict the permanent failure before the failure of the strong link（such as explosive initiator）,so that the expected safety objective is obtained.A design success is defined to be that the weak-link fails before the failure of the strong link,under which condition the system is safe;and a design invalidation means that the weak-link fails after the failure of the strong link,under which condition the system loses in safety.The probability of safety loss exists due to the uncertainty of the failure temperatures of the weak-link/strong-link.To get the probability of the safety loss,a probability method was used to deal with the uncertainty of the failure temperatures.The integral method and stochastic simulation method were used to compute the results.Finally,a simple sample was given to prove the results given by the two methods to be identical.