约束状态对混凝土温度变形和温度应力的影响探讨

发布时间：2018-01-06 00:19

本文关键词：约束状态对混凝土温度变形和温度应力的影响探讨　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：温度应力是一项重要的结构荷载,有时甚至会成为结构在运行过程中开裂或破坏的关键因素。绝大多数混凝土建筑物所处环境的温度都是交替变化的,温度应力的产生和影响是无法避免的。基于混凝土温度应力分析和测定的重要性和混凝土温度应力计算值与实测值存在着较大差异,本文通过设计实验方法,进行实验室直接测定混凝土试件的温度变形的温度应力。通过实测的温度变形和温度应力与理论计算的结果对比,探讨分析各个影响因素对混凝土温度变形和温度应力的影响。试验结果表明,在温度变化大致相同时,混凝土试件的温度变形量与其初始应力状态密切相关,初始压应力越大,试件所受的约束作用越强,产生的温度变形量越小。针对实测温度应力小于理论计算温度应力的问题主要进行以下探讨:一、简单推导对了弹性力学的温度应力理论计算公式。二、试验验证了混凝土弹性模量在常温范围内(20~70℃)的随温度变化是可以忽略不计的。三、对受压状态下混凝土的热膨胀机理进行了探讨。首先探讨了均匀材料的受压热膨胀机理,混凝土材料在这个基础上还有自身独特的变形规律。其次用钢管的温度变形试验验证了钢管在受压状态下的温度变形规律,证实钢管在受压情况下,其温度膨胀变形也要小于自由状态,但是受压状态下钢管温度变形量的减小程度要比混凝土试件小得多。四、根据已有的研究成果和试验过程中实际温度变形量小于理论计算量的试验现象,着重分析了混凝土试件在受压状态下的温度变形规律,提出了“混凝土温度变形系数φ”新概念,并利用温度应力理论计算公式反演分析,得到了混凝土温度变形系数φ与混凝土初始压应力的关系。通过这些探讨分析,在实际工程中,当计算结构或者构件的温度应力时,应该考虑应力状态对其温度变形性能的影响。
[Abstract]:The temperature stress is an important structural load, sometimes even will become a key factor in cracking or failure during operation. The vast majority of concrete buildings, the environmental temperature is alternating, and the influence of temperature stress is unavoidable. The concrete temperature stress calculation value exists the big difference with the measured value of stress analysis and determination of the importance and concrete temperature based on the experimental design method for direct determination of laboratory concrete specimen temperature deformation temperature stress. The temperature deformation and temperature stress calculation of measured and theoretical results, to explore the influence of various factors on temperature deformation analysis the temperature and stress of concrete. The experimental results show that the temperature changes are almost the same, the temperature and the initial deformation stress state is closely related to concrete, initial pressure The greater the stress test, the stronger one by a constraint, the temperature deformation amount is smaller. According to the measured temperature stress is smaller than the theoretical calculation of the temperature stress problem is mainly the following discussion: first, simple derivation of the formula of elastic mechanics theory. The temperature stress of the concrete elastic test two. Modulus in the normal range (20~70 C) with the change of temperature is negligible. Three, the expansion mechanism of concrete under compression heat are discussed. First discusses the expansion mechanism of Pressurized Thermal homogeneous materials, concrete materials on this basis has its own unique deformation law. Secondly with the temperature of steel pipe deformation tests verify the deformation temperature under compression of the steel pipe, steel pipe that under the pressure, the temperature is less than the expansion of the free state, but the amount of deformation of the steel tube temperature under load decreases To a little more than a concrete test. Four, according to the phenomenon of the actual temperature deformation is less than the theoretical calculation results and the test process, analyzes the parts under compression temperature deformation of concrete, put forward the "new concept of temperature deformation coefficient, and using temperature calculation inversion formula for stress analysis theory, the relationship of concrete temperature coefficient and concrete initial deformation stress. Through these analysis, in practical engineering, when calculating the structure or component of the temperature stress, should be considered the stress state of deformation performance of the temperature.

【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU528

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