变截面组合梁剪力滞后效应有限差分解析求解方法研究  

Research on Finite Difference Analytical Solution Method for Shear Lag Effect of Variable Cross Section Composite Beams

作　　者：苗林 MIAO Lin(Shanghai Foundation Engineering Group Co.,Ltd.,Shanghai 200002,China)

机构地区：[1]上海市基础工程集团有限公司,上海200002

出　　处：《建筑施工》2021年第4期707-709,717,共4页Building Construction

摘　　要：在钢-混凝土组合梁中,由于混凝土板的剪切变形而产生的"剪力滞后效应",会对组合梁的刚度、承载能力和变形的计算结果产生影响,是钢-混凝土组合梁设计和研究中需要解决的关键问题。通过将混凝土板宽范围内的应力不均匀分布表述为翘曲位移形状函数与翘曲强度函数的乘积形式,由变分法得到组合梁平衡微分方程,并引入剪力滞后系数描述组合梁混凝土板横截面应力分布不均匀特性。在此基础上,采用有限差分法求解变截面组合梁剪力滞后效应,推导出了常见结构形式的有效宽度解析表达式,通过与Ansys模拟结果和规范方法进行对比,验证了算法的有效性,并明确了使用范围,为今后钢-混凝土组合梁剪力滞后效应计算提供了高效的运算手段。In steel-concrete composite beams,the shear lag effect caused by shear deformation of concrete slabs will affect the calculation results of stiffness,bearing capacity and deformation of composite beams,which is a key problem to be solved in the design and research of steel concrete composite beams.The uneven distribution of stress in the width range of concrete slab is expressed as the product-form of the warping displacement shape function and the warping strength function,the equilibrium differential equation of composite beam is obtained by variational method,and the shear lag coefficient is introduced to describe the uneven distribution of stress in the cross sections of composite beam concrete slabs.On this basis,the finite difference method is used to solve the shear lag effect of variable cross-section composite beams,and the analytical expression of effective width of common structural forms is derived.Compared with the ANSYS simulation results and the code method,the effectiveness of the algorithm is verified,and the application scope is defined,which provides an efficient calculation method for the shear lag effect calculation of steel concrete composite beams in the future.

关 键 词：钢-混凝土组合梁 剪力滞后 有效宽度 有限差分 解析解 

分 类 号：TU755[建筑科学—建筑技术科学]