Abstract:

A nonlinear relation between concrete creep and its thermal stress appears when the thermal stress is more than the half tensile strength of corresponding aged concrete. A nonlinear creep model of concrete is adopted to simulate its thermal stress; and a numerical algorithm is also presented. With the advantage about temperature crack propagation, element-free Galerkin method(EFGM) is adopted to simulate temperature crack propagation. A numerical example shows that EFGM is of good accuracy and reliability; and crack depth and extension speed of concrete after considering nonlinear creep effect are less than those only considering linear creep because of that the rapid increased nonlinear creep at the cracking moment relaxed thermal stress at crack tip.

Key words: concrete, nonlinear creep, element-free method, temperature crack, numerical simulation