扣件式钢管支模架稳定承载能力研究

A study on the stability bearing capacity of fastener-style tubular steel formwork-supports

在直角扣件抗扭刚度试验基础上,考虑扣件连接的半刚性,建立了扣件式钢管支模架稳定承载能力分析的三维有限元模型。采用线性屈曲和非线性屈曲分析方法计算支模架的稳定承载力,结果表明线性屈曲所得的稳定承载力要大于非线性稳定计算结果,尤其是在有初始缺陷时由线性屈曲所得的稳定承载力是不尽合理的。然后采用非线性屈曲方法,计算了不同搭设变量下的稳定承载力,并表示为工程上常用的计算长度系数。对稳定承载力的影响因素进行了分析,指出支模架的初始缺陷、扣件半刚性对支模架稳定承载力的影响比较显著,扣件螺栓拧紧力矩定为40N.m是经济合理的。本文的研究成果可作为扣件式钢管支模架稳定性设计的依据。

Considering semi-rigid connections, a 3-D FEM was established to simulate the fastener-style tubular steel formwork-support and the analysis was performed together with an experimental study of the torsion stiffness of right couplers. Both the linear and nonlinear buckling techniques were employed to determine the stability of the formwork-supports. In the nonlinear analytical model, Initial imperfection, plastic behavior and large deflection response of the formwork-supports were taken into account. Numerical results indicated the linear buckling loads were higher than that obtained from the nonlinear stability analysis. Nonlinear buckling analysis was employed to calculate the stability bearing capacity for cases of different design variables, and then the results were converted into effective length coefficients that are generally used in practice. The influence factors on the stability bearing capacity were studied. It was pointed out that the effects of initial imperfection and semi-rigid connection on the stability bearing capability are important, also a bolt tightening torque of 40N-m was found to be quite reasonable.