An Adaptive Degree of Freedom Condensation Algorithm for Simulating Transient Temperature, Applied to an Asphalt-Concrete Core Wall

To solve the problem of the high cost of transient temperature simulation in the whole construction process of an asphalt-concrete core wall, a novel adaptive degree of freedom condensation algorithm for simulating transient temperature is proposed. This method establishes the judgment criterion of degree of freedom condensation based on the error estimator of mesh and the artificial energy added by degree of freedom condensation. In this method, the transformation matrix between the master and slave degrees of freedom is constructed based on the shape function interpolation relationship between the initial coarse mesh and the multi-level refined mesh. In the transient calculation process, this method can automatically identify the positions where temperature distribution and value are stable and condense the considered slave degrees of freedom to master degrees of freedom through the transformation matrix at any time to reduce the unnecessary degrees of freedom. In this paper, three numerical examples show that the proposed method can effectively reduce the cost of matrix factorization and the solving the equation in the finite element method at the cost of small precision loss in the long-term transient temperature simulation.