基于随机和认知不确定性分离的PBX构件可靠性分析

由概率或概率盒方法量化高聚物粘结炸药(PBX)构件几何尺寸、材料属性、所受载荷等参数的不确定性,通过嵌套抽样法进行了不确定性传播分析,以分离随机和认知不确定性的影响。定量叠加了数值误差和模型形式误差,最终获得结构关心响应量的不确定性和炸药件的可靠度区间,与传统确定性的强度校核方法以及经典概率方法的可靠性分析结果进行了比较。结果表明,考虑不确定性的可靠性评估比传统确定性强度校核降低了工程应用的风险,而本方法给出的可靠度区间包含了经典概率方法计算的可靠度,在认知不确定性影响严重时仍然适用,并随着认知不确定性的缩减收敛于真实可靠度。

Reliability Analysis of Polymer Bonder Explosive Based on Separation between Aleatory Uncertainty and Epistemic Uncertainty

The uncertainties of model parameters, structural geometry, material property, and external force of the polymer bonder explosive, were quantified with probability box and propagated with nested sampling method in order to separate the different effect of aleatory uncertainty and epistemic uncertainty on response of interest. Moreover, numerical error and model form error were also quantitatively superposed to acquire the response uncertainty and the reliability interval of the polymer bonder explosive(PBX)structure consequently. In addition, the results of proposed method in this paper were compared with the determinate checking method and the probabilistic reliability method. It is indicated that the reliability assessment with the consideration of uncertainty can reduce the engineering risk than the determinate method. Furthermore, the reliability interval obtained by the proposed method covers the reliability calculated by probabilistic method, and can narrow down to the true reliability as the epistemic uncertainty decreases.