基于可变容差法碾压混凝土坝温度场反分析研究

Inverse analysis of RCC dam temperature field based on flexible tolerance method

大体积混凝土温度计算模型和热学参数的准确性直接影响温度场仿真计算的成败,而精确地进行温度计算所需的一些材料参数往往不易直接测得,需要根据一些易测得的量进行反求。基于三维瞬态温度场有限元求解理论与反问题理论,建立了混凝土三维瞬态温度场反问题求解数值模型。运用可变容差法寻求非线性反演问题全局最优解,只需要若干点的温度实测值便可实现混凝土多个热学参数如绝热温升、导温系数及表面放热系数等的同时反演,算例对该反演方法的反演精度及数值稳定性给出了满意的证明。

The accuracy of the temperature calculating model and the thermal parameters influence the success or failure of the simulation of mass concrete temperature field.However,some requisite material parameters for precise temperature filed computation cannot be acquired by direct measurement,and need to be obtained by inverse calculation according to some easily measured values.We establish an inverse problem solution numerical model for three-dimensional transient temperature field based on the theory of three-dimensional transient temperature field and inverse calculation.The global optimum solution of nonlinear inverse problem is obtained by flexible tolerance method,and the presented method can simultaneously achieve the inversion of several thermal parameters with only a few sets of measured temperature values,such as adiabatic temperature rise,temperature diffusivity and surface heat transfer coefficients.The example proves the high accuracy and numerical stability of the method.