基于静态变量嵌入机制的RNN时变可靠性分析方法
A TIME-DEPENDENT RELIABILITY ANALYSIS METHOD BASED ON RNN WITH STATIC-VARIABLE EMBEDDING MECHANISM
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摘要: 为解决工程结构在动态载荷和材料退化作用下可靠性评估随时间演化的复杂问题, 本文提出了一种基于循环神经网络(RNN)的高效时变可靠性分析方法. 所提方法本质上是一种数据驱动的代理模型, 通过学习历史响应数据, 在保持较低计算成本的同时实现高精度预测. 不同于传统解析模型依赖显式的响应函数表达, RNN自动提取静态随机变量与时变随机过程之间的非线性耦合关系. 在网络结构上设计静态变量嵌入机制, 使时间无关变量在每个时间步持续参与建模, 从而强化模型对系统全生命周期响应的表征能力. 同时引入Huber损失函数, 兼顾预测精度与对异常样本的鲁棒性. 数值实验表明, 该方法使用极少量训练样本, 即可逼近105次蒙特卡洛模拟(MCS)的估算精度. 本方法不仅能准确估计极限状态函数最小值, 还可对指定时间区间内的系统响应曲线实现全局预测, 拓展了其在实际工程中的适用性. 在多场景鲁棒性测试中, 平均误差始终低于0.25%, 充分验证了其泛化能力与稳定性. 综合结果表明, 该方法保持高精度的同时显著降低样本需求, 能够在复杂系统时变可靠性分析中实现高效稳定的建模预测.Abstract: To address the complex challenge of time-varying reliability assessment in engineering structures subjected to dynamic loads and material degradation, this study proposes an efficient analysis method based on recurrent neural networks (RNN). The proposed approach functions as a data-driven surrogate model that learns from historical response data to achieve high-accuracy predictions at low computational cost. Unlike traditional analytical models that rely on explicit response functions, the RNN architecture automatically captures the nonlinear coupling between static random variables and time-dependent stochastic processes. A static variable embedding mechanism is designed within the network, enabling time-invariant variables to participate in modeling at every time step, thereby enhancing the model’s ability to represent system responses over the entire life cycle. Additionally, the Huber loss function is introduced to improve training robustness while maintaining predictive accuracy. Numerical experiments show that the proposed method can closely approximate the results of 105 Monte Carlo simulations (MCS) using a minimal number of training samples. The proposed approach can not only accurately estimate the minimum of the limit state function, but also achieve global prediction of the system response curve within any specified time interval, expanding its applicability in practical engineering scenarios. Robustness tests under various perturbation settings show that the average prediction error consistently remains below 0.25%, demonstrating strong generalization and stability. Overall, the proposed method maintains high prediction accuracy while significantly reducing sample requirements, enabling efficient and reliable modeling of time-dependent reliability in complex systems.
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