Department of Civil and Environmental Engineering, Princeton University, Princeton, NJ 08544, USA.
Sensors (Basel). 2022 Sep 22;22(19):7190. doi: 10.3390/s22197190.
Concrete exhibits time-dependent long-term behavior driven by creep and shrinkage. These rheological effects are difficult to predict due to their stochastic nature and dependence on loading history. Existing empirical models used to predict rheological effects are fitted to databases composed largely of laboratory tests of limited time span and that do not capture differential rheological effects. A numerical model is typically required for application of empirical constitutive models to real structures. Notwithstanding this, the optimal parameters for the laboratory databases are not necessarily ideal for a specific structure. Data-driven approaches using structural health monitoring data have shown promise towards accurate prediction of long-term time-dependent behavior in concrete structures, but current approaches require different model parameters for each sensor and do not leverage geometry and loading. In this work, a physics-informed data-driven approach for long-term prediction of 2D normal strain field in prestressed concrete structures is introduced. The method employs a simplified analytical model of the structure, a data-driven model for prediction of the temperature field, and embedding of neural networks into rheological time-functions. In contrast to previous approaches, the model is trained on multiple sensors at once and enables the estimation of the strain evolution at any point of interest in the longitudinal section of the structure, capturing differential rheological effects.
混凝土表现出受徐变和收缩驱动的时变长期行为。由于其随机性和对加载历史的依赖性,这些流变效应难以预测。现有的用于预测流变效应的经验模型是根据主要由实验室测试组成的数据库进行拟合的,这些数据库的时间跨度有限,无法捕捉到不同的流变效应。通常需要数值模型将经验本构模型应用于实际结构。尽管如此,实验室数据库的最优参数对于特定结构来说并不一定理想。使用结构健康监测数据的基于数据的方法已显示出在准确预测混凝土结构的长期时变行为方面的潜力,但目前的方法需要为每个传感器使用不同的模型参数,并且不能利用几何形状和加载。在这项工作中,引入了一种用于预应力混凝土结构二维法向应变场长期预测的物理启发式数据驱动方法。该方法采用结构的简化分析模型、用于预测温度场的数据驱动模型以及将神经网络嵌入流变时间函数中。与以前的方法相比,该模型可以同时对多个传感器进行训练,并能够估计结构纵向任意感兴趣点的应变演化,从而捕捉到不同的流变效应。