基于内力分配法的组合梁徐变应力重分布实用计算

发布时间：2018-11-24 13:13

【摘要】：为获得组合梁徐变应力重分布的计算公式,以一个单轴对称并受到弯矩和轴力作用的组合梁截面为研究对象,采用混凝土徐变的微分本构关系,用内力分配法得到组合梁弯矩和轴力重分布的微分方程组。为避免求该方程组的精确解所需复杂的数学计算,通过有效的简化获得方程组的实用近似解,并通过算例进行精确性验证。计算结果表明:方程组近似解与精确解的误差非常小,能达到合理的计算精度;混凝土徐变对组合梁长期应力影响显著,计算时应得到足够的重视。采用的内力分配法适用性较广,无论是何种荷载形式、结构形式,只要内力能换算成作用在组合梁截面中和轴处的弯矩和轴力,都可以使用该方法。
[Abstract]:In order to obtain the calculation formula of creep stress redistribution of composite beam, the differential constitutive relation of concrete creep is adopted to study the section of a uniaxial symmetric composite beam subjected to bending moment and axial force. The differential equations of bending moment and axial force redistribution of composite beam are obtained by internal force distribution method. In order to avoid the complicated mathematical calculation needed to obtain the exact solution of the equations, the practical approximate solutions of the equations are obtained by simplifying effectively, and the accuracy of the equations is verified by an example. The results show that the error between the approximate solution and the exact solution of the equations is very small, and the concrete creep has a significant effect on the long-term stress of the composite beam, and it should be paid enough attention to in the calculation. The internal force distribution method is widely used, no matter what kind of load form or structure form, so long as the internal force can be converted into bending moment and axial force acting on the section and axis of composite beam, this method can be used.
【作者单位】：昆明理工大学土木工程学院;昆明冶金高等专科学校建工学院;
【基金】：国家自然科学基金地区资助项目(51268022);国家自然科学基金青年项目资助(51308269) 教育部博士点基金资助项目(20095314110008)
【分类号】：TU398.9

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