火工切割器的一种小样本可靠性验证试验

A Reliability Validation Test with Small Samples for Pyrotechnic Cutters

提出了火工切割器的一种小样本计量型可靠性验证试验方法及偏保守的可靠性评估方法,将火工切割器的燃气压力峰值作为可靠性特征量进行可靠性验证试验,分别测试额定工况(双边点火工况)下的燃气压力峰值和单边点火工况下的燃气压力峰值。基于应力—强度干涉理论,用小样本可靠性验证试验数据开展可靠性评估。这种验证方法既可避免特征量临界值分布规律摸底试验中消耗一定数量的产品,又能实现计量法代替计数法,还避免了人为设定强化系数,评估结果能够反映产品在加严条件下的可靠度水平。文章给出了用60个火工切割器样本进行可靠性验证试验及可靠性评估的应用实例,为航天器火工装置小样本可靠性验证提供技术途径。

A reliability validation test method and a conservative reliability assessment method for pyrotechnic cutters were put forward based on characteristic parameter measurements with small samples.As characteristic parameters,the peak gas-pressures of the cutter in the rated condition（bilateral ignition）and in the unilateral ignition condition were measured in the test. Based on the generalized strength-stress theory, the reliability assessment was carried out by test data with small samples.The proposed reliability validation test method not only avoids consuming more test products to obtain critical value distribution of the characteristic parameters,but also utilizes characteristic parameter variables instead of counting the success number of samples. Besides, This method doesn′t need artificial intensification coefficients. Hence,the reliability assessment results can reflect the real reliability level of the products in the worse working conditions.An application example was given,in which only 60 test samples of the pyrotechnic cutter were used for the reliability validation test and the reliability assessment.The method contributes to the small sample reliability assessment of pyrotechnic devices in spacecraft.