早期混凝土热学参数优化及温度场精确模拟

发布时间：2018-01-11 08:27

本文关键词：早期混凝土热学参数优化及温度场精确模拟　出处：《四川大学学报(工程科学版)》2014年03期 　论文类型：期刊论文

【摘要】：早期混凝土温度场变化剧烈,其生热过程、导热性能都与水化过程密切相关。综合混凝土绝热温升方程、热学参数和边界条件3个方面,进行了早龄期混凝土热学参数优化和温度场精确模拟的研究。在室内试验基础上,采用Python语言编写遗传算法程序,并将二次开发的ABAQUS温度场子程序嵌入到遗传算法中,进行了绝热温升方程的参数优化;考虑导热系数和比热变化,开发了基于水化度的热学参数子程序。采用优化后绝热温升方程对某工程实例进行了对比研究,结果表明:热学参数变化对早期混凝土的温度场分布有重要影响,考虑水化度热学参数变化的工况比不考虑该参数变化的工况,承台内部温度最高值增大7.28%,表面温度最高值增大14.30%,内外温差增大3.81%,内外温差值较高的范围也较大。研究成果能更为精确地预测结构早期应力和开裂。
[Abstract]:The temperature field of early concrete varies dramatically, and its heat generation and thermal conductivity are closely related to the hydration process. The comprehensive adiabatic temperature rise equation of concrete, thermal parameters and boundary conditions are three aspects. The optimization of thermal parameters and accurate simulation of temperature field of early age concrete were studied. On the basis of indoor test, genetic algorithm was programmed by Python language. The secondary developed subprogram of ABAQUS temperature field is embedded into genetic algorithm to optimize the parameters of adiabatic temperature rise equation. Considering the variation of heat conductivity and specific heat, a subprogram of thermal parameters based on hydration degree is developed, and an engineering example is studied by using the optimized adiabatic temperature rise equation. The results show that the variation of thermal parameters has an important effect on the temperature field distribution of early concrete. The maximum value of the inner temperature of the cap increases 7.28%, the highest value of the surface temperature increases 14.30%, and the difference between inside and outside temperature increases 3.81%. The range of higher internal and external temperature difference is also large, and the research results can more accurately predict the early stress and cracking of the structure.
【作者单位】：天津大学水利工程仿真与安全国家重点实验室;
【基金】：国家自然科学基金创新研究群体科学基金资助项目(51021004);国家自然科学基金资助项目(51279126)
【分类号】：TU528
【正文快照】： 早期混凝土经历了从流态、塑性到固态的变化过程,其温度场变化剧烈。要精确模拟整个过程中温度场的变化,必须同时考虑水化过程中混凝土的自生热、热交换、导热等相关参数的变化。热学参数的合理与否关系到温度场结果的真实程度,其中,混凝土导热系数、比热等都随时间、温度等变

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