Time-dependent reliability analysis remains challenging in practical engineering applications, since the modeling and solution are complicated, resulting in the huge computational burden. The composite limit state (CLS) method can efficiently reduce the computational cost to a certain extent. However, the computational cost is still high. In this article, an improved composite limit state (ICLS) method is proposed for efficient time-dependent reliability analysis, which is based on the original CLS. We propose two enhancements to improve the efficiency of the ICLS approach. First, different from the original method, Kriging surrogate models at all time nodes and one CLS Kriging surrogate model are established in the ICLS method, respectively. In that case, once a new sample is selected, there is no need to evaluate the true limit state function values on the new sample at each time node, leading to a reduction in computational cost. Next, the efficiency is further improved by updating the CLS Kriging surrogate model and the surrogate model at one selected time node simultaneously. Four examples are utilized to demonstrate the efficiency and accuracy of the ICLS method for time-dependent reliability analysis.

随时间进行的可靠性分析在实际工程应用中仍然具有挑战性，因为建模和解决方案很复杂，从而导致巨大的计算负担。复合极限状态（CLS）方法可以在一定程度上有效降低计算成本。但是，计算成本仍然很高。在本文中，基于原始CLS，提出了一种改进的复合极限状态（ICLS）方法，用于有效的时变可靠性分析。我们提出了两项​​改进措施，以提高ICLS方法的效率。首先，与原始方法不同的是，在所有时间节点上分别使用ICLS方法建立了Kriging替代模型和一个CLS Kriging替代模型。在这种情况下，一旦选择了新样本，无需在每个时间节点上评估新样本的真实极限状态函数值，从而降低了计算成本。接下来，通过同时更新一个选定的时间节点上的CLS克里金代理模型和代理模型，进一步提高了效率。利用四个例子来说明用于依赖时间的可靠性分析的ICLS方法的效率和准确性。