摘要
本文用有限元法从砼的水分扩散方程中求出湿度和自由干缩应变场,分别由砼的线性和非线性蠕变理论及拉应变软化模型,推导出计算砼构件的干缩应力的递推公式,并编制了电算程序。计算表明,非线性理论的结果与线性理论的结果相差不大,而拉应变软化模型的结果与前两者有较大差异。
Maximum tensile shrinkage stress in drying concrete members often exceeds 0.5ft(tensile strength),which calls for nonlinear theory to be used. Recursive formulas to compute long-term shrinkage stresses by nonlinear creep theory and linear creep theory with strain-softening are derived in this paper respectively. Numerical examples are presented.One important conclusion is that nonlinear creep theory gives almost the same results as those of linear one,but gives rather different results from those of strain-softening model.
