中文摘要：

在进行结构可靠性分析时，将影响结构功能的不确定性设计变量用区间数描述，建立结构可靠性分析的区间应力-区间强度干涉模型。针对两个区间变量情况的区间应力-区间强度干涉模型，定义了结构安全可能度和失效可能度，形成在设计变量分布形式已知或未知时都适用的结构区间可靠性分析的可能度法，建立了结构区间可靠性分析的可能度准则。分析了结构区间可靠性分析可能度法具有的良好数学性质。在已知设计变量在区间取值范围内都服从均匀分布的前提下，研究了结构安全可能度和概率可靠度的关系，认为结构安全可能度可以对结构安全或可靠的程度做出合理的估计。算例验证了区间可靠性分析可能度法的有效性。

英文摘要：

Interval stress--interval strength interference model was built for structural interval reliability analysis, when interval numbers were used to represent the uncertain design variables affecting the structural performance. Structural safety possibility degree（SPD） and failure possibility degree（FPD） were formulated for this interference model with two variables. Possibility degree method, with good mathematical characteristics, for analysis of structural interval reliability was proposed,which can be used whenever there was enough probability information or not. Further, the relationship between structural SPD and probability reliability were investigated under the assumption that all design variables were uniform distributed in their interval range. The conclusion is that a reasonable evaluation for the grade of structural safety or reliability can be provided by SPD. The effectiveness of SPD method for structural interval reliability analysis was illustrated by a simple example.