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对变应力作用下的拉压异性徐变的弹性徐变方程的求解进行了探讨,基于混凝土的徐变度与混凝土的龄期有关和线性叠加假设,采用应力增量法,推导了变应力作用下的拉压异性徐变的弹性徐变问题的有限元计算公式。由于拉伸和压缩徐变速率相近,假设拉伸和压缩徐变一致时的徐变应变增量递推公式,与假设拉伸和压缩徐变异性的徐变应变增量的递推公式形式上一样,仅当某时刻的应力增量主量为负时,采用压应力下的徐变度,当某时刻的应力增量主量为正时,采用拉应力下的徐变度。实际混凝土工程的拉压异性徐变应力仿真分析表明,在高温季节浇筑混凝土时,昼夜温差将引起应力周期性加卸载变化,假设拉伸和压缩异性徐变时计算的混凝土温度拉应力较拉压相同徐变时计算的混凝土温度拉应力更大,且这个应力随着仓面间歇时间的延长而逐渐增大。
The solution to the elastic creep equation of the creep deformation under tension and compression under the action of stress is discussed. Based on the creep of concrete and the age-related and linear superposition of concrete, the stress increment method is used to deduce the effect of stress-strain Finite element calculation formula of creep elastic creep under tension and compression. Due to the similar creep rate of tension and compression, assuming that the creep strain increment recursion formula when the tensile and compressive creep coincide, and the recursive formula of the creep strain increment assuming the tensile and compressive creep difference formally Similarly, the creep degree under compressive stress is used only when the principal amount of stress increment at a certain time is negative, and the creep degree under tensile stress is adopted when the principal amount of stress increment at a certain time is positive. The simulation analysis of tensile and compression heteroscedastic creep stress of actual concrete engineering shows that the temperature difference between day and night will cause the periodic loading and unloading of concrete when the concrete is poured in the high temperature season. Supposing the tensile and compressive stress creep, The calculated concrete temperature tensile stress is greater when the same creep, and the stress increases with the extension of the intermittent time.