基于Winkler弹性地基梁模型的半刚性轻钢柱脚底板受力分析
MECHANICAL ANALYSIS OF THE SOLE PLATE OF SEMI-RIGID LIGHT STEEL COLUMN FOOTINGS BASED ON WINKLER MODEL OF ELASTIC FOUNDATION BEAMS
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摘要: 为建立半刚性轻钢柱脚底板压力分布计算模型, 基于Winkler弹性地基梁模型及其变形和内力初参数表达式, 给定边界条件, 利用Maple软件, 获得了两端自由弹性地基梁在任意集中力和任意梯形线荷载作用下的挠度解析公式, 将半刚性方钢管柱脚底板简化为支承在混凝土基础上的弹性地基梁, 根据力的等效原则, 建立了偏心受压时柱脚底板受力模型, 得到了柱脚底板压力分布解析解, 通过算例与数值摸拟结果对比, 结果表明二者吻合较好, 且半刚性轻钢柱脚底板压力分布与常用线性压力分布模型差别较大, 采用线性压力分布模型将过高估计柱脚刚度。研究成果为半刚性轻钢柱脚设计提供理论参考。Abstract: To calculate the pressure distribution on the sole plate of semi-rigid light steel column footings, the analytical formulation of deflection of beams with free ends resting on elastic foundations under arbitrary concentrated loads and trapezoidal loads was derived. The derivation, using the software package Maple, was based on the Winkler model of elastic foundation beams with the associated initial parameter expressions of deformation and internal forces. The sole plate of semi-rigid square steel tube column footings was simplified as an elastic foundation beam supported by concrete foundations. A mechanical model of the sole plate under eccentric loading was proposed, and the analytical solution of pressure distribution on the sole plate was obtained. Results from the analytical solution were compared against numerical simulations with a satisfactory level of agreement. The calculated pressure distribution on the sole plate was noted to differ greatly from the commonly- recognised linear distribution, which overestimates the stiffness of semi-rigid column footings. The findings from this study are expected to provide guidelines to the design of semi-rigid light steel column footings.