钢筋混凝土双向偏压构件正截面承载力的图算法  

Graph algorithm on normal section bearing capacity of RC members subjected to axial loads and biaxial bending

作　　者：双超 周东华[1] 李露[1] 兰树伟 Shuang Chao;Zhou Donghua;Li Lu;Lan Shuwei(Kunming University of Science and Technology,Kunming 650500,China)

机构地区：[1]昆明理工大学,云南昆明650500

出　　处：《土木工程学报》2020年第9期77-84,共8页China Civil Engineering Journal

基　　金：国家自然科学基金(51668027)。

摘　　要：钢筋混凝土双向偏压构件的特点是配筋计算十分困难,原因是钢筋和混凝土材料的非线性使得叠加原理变为失效,即不能按单向偏心计算后再叠加。目前的近似计算是假设双向弯矩与轴力的相关曲线作为极限承载力曲线,这种假设过于粗简,适用性差;若要精确计算,则须数值计算和迭代求解,这样不便实际运用,不能手算。针对这一状况,文章用逆算法,由已知应变求应力和内力,无须迭代,也不用叠加原理,便可得到双向偏压截面的配筋,还有很好的计算精度。为了方便运用,文章绘制了用于配筋计算的无量纲诺模图,并用该图与数值计算的结果进行了比较,两者吻合较好。另外,诺模图还具有这些特点:计算简单快速,适用性强,可用于任意截面尺寸大小和任意普通混凝土强度等级。The reason for the difficulty in calculating RC members subjected to axial loads and biaxial bending is that the non-linearity of the reinforcement and concrete materials makes the superposition principle invalid, that is, it cannot be calculated by superposing the calculation results of unidirectional eccentricity.Nowadays, by assuming the correlation curve between the bidirectional moments and the axial force as the ultimate bearing capacity curve, the calculation accuracy and the feasibility of the assumption are poor;numerical calculation and iterative solution can be used to meet the requirements on accuracy, but they are difficult to be applied in practice and hand calculation is almost infeasible.In view of this situation, the inverse algorithm, in which the stresses and the internal force can be calculated without resorting to the iterative method and the superposition principle, is used with good calculation accuracy.In order to facilitate its application, a dimensionless nomogram for the calculation of reinforcement is charted in this work.By comparing this chart with the numerical calculation result, good agreements can be achieved.In addition, the nomogram also has the following advantages: simple and fast calculation, strong applicability, applicable for any cross-sectional size and any strength grade of concrete.

关 键 词：钢筋混凝土结构 正截面承载力 图算法 相关曲线 无量纲公式 

分 类 号：TU375[建筑科学—结构工程]