大体积混凝土温度场高速求解方法的改进

Improvement of fast solution method for mass concrete temperature fields

在超松弛预条件共轭梯度法(SSOR-PCG)的基础上,提出了变初值的迭代方法.该方法用前一时间步的温度值作为下一时间步的初值,与原来方法相比,求解速度可提高1/3左右.采用该迭代解法编制了温度场有限元程序,并对某碾压混凝土重力坝的瞬态温度场进行了仿真计算.计算结果表明,该方法具有很快的求解速度,20万自由度的温度场计算,求解1次(1个时间步)只需31 s.

An iterative method for determining variable initial values is proposed based on the symmetric successive overrelaxation preconditioned conjugated gradient （SSOR-PCG） method. The temperature value of the previous time step is regarded as the initial value of the next time step. Compared with the original approach, the solution speed increases by about 1/3. Using the iterative method, a finite element program for the temperature fields was compiled and was employed to simulate the transient temperature fields of a RCC gravity dam. The calculated results show that the present method has a high solution speed. For example, only 31 seconds are needed to solve a temperature field with 20 × 10^4 DOF once （one time step）.