考虑性态变化的早期混凝土热湿力耦合分析及其应用

发布时间：2018-07-23 20:43

【摘要】：温度、湿度是引起混凝土早期开裂的重要原因,早期混凝土性态与温度、时间变化密切相关,但已有方法在模拟二者组合效应上存在明显缺陷。为了更加真实地模拟早期混凝土应力场,合理评价结构开裂风险,基于ABAQUS二次开发平台,编写基于水化度理论和考虑热学参数变化的温度场计算子程序;考虑温度对湿度扩散系数影响的湿度场计算子程序;基于成熟度理论和双幂徐变函数的应力场子程序,并通过算例验证了子程序开发的合理性。采用顺序耦合方法,将温度场、湿度场和应力场子程序应用于工程实例,研究结果表明:结构温度前期主要受水化热影响,后期随大气温度变化,但有一定滞后性;干缩变形主要对表面应力产生较大影响;考虑湿度影响后,结构内部应力有所减小;结构表面开裂是温度与干缩联合作用的结果,内部开裂则主要由温度引起。
[Abstract]:Temperature and humidity are the important causes of early cracking of concrete. The behavior of early concrete is closely related to temperature and time change, but there are obvious defects in simulating the combined effect of the two methods. In order to simulate the stress field of early concrete and evaluate the structural cracking risk reasonably, based on the secondary development platform of ABAQUS, the subprogram of temperature field calculation based on hydration degree theory and taking into account the variation of thermal parameters is compiled. Considering the influence of temperature on the humidity diffusion coefficient, the subroutine of humidity field calculation and the stress field subprogram based on maturity theory and double power creep function are considered, and the rationality of the development of the subprogram is verified by an example. Temperature field, humidity field and stress field are applied to engineering examples by using sequential coupling method. The results show that the structure temperature is mainly affected by hydration heat in the early stage and changes with the atmospheric temperature at the later stage, but it has a certain lag. Dry shrinkage deformation mainly affects the surface stress; considering the effect of humidity, the internal stress of the structure decreases; the surface cracking of the structure is the result of the combination of temperature and dry shrinkage, while the internal cracking is mainly caused by temperature.
【作者单位】：天津大学水利工程仿真与安全国家重点实验室;天津市市政工程设计研究院;
【基金】：国家自然科学基金创新研究群体科学基金(51021004);国家自然科学基金(51279126)
【分类号】：TU528

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