横向冲击下圆钢管混凝土构件挠度计算方法研究

Calculation method of the deflection of circular concrete filled steel tubular members under transverse impact load

为了对圆钢管混凝土(CFST)构件遭受横向冲击下的挠度计算方法进行研究,在刚塑性假定的基础上,推导出了构件在任一点遭受横向冲击下的最大挠度理论计算公式。考虑到能量损失和局部变形等实际情况与刚塑性假定的差异性,以55根圆钢管混凝土构件冲击作用下的挠度试验数据作为统计样本,拟合得到挠度计算公式的修正系数,用于修正刚塑性假定导致的计算误差。修正后公式的适用范围为:冲击质量在193.35~920.00 kg;冲击速度在3.96~14.48 m/s。对于敏感因素套箍系数,两端固支时,套箍系数在0.5~2.0;两端简支时,套箍系数在0.500~1.617;一端固支一端简支时,套箍系数在0.500~1.307。为了验证修正后挠度计算公式的准确性,通过数值模拟的方法拓展样本,并将修正后挠度计算公式的理论计算结果和数值模拟结果进行对比,误差在10%以内,证明了提出的修正后挠度理论计算公式精度良好。

In order to investigate the deflection of circular concrete-filled steel tubular(CFST)members subjected to transverse impact at any position,a theoretical formula for calculating the deflection of the members was derived based on the rigid-plastic assumption.The deflection test data of 55 CFST members under lateral impact were selected as statistical samples,and the correction factor was then obtained to correct the error caused by the difference between the rigid plastic hypothesis and the actual situation such as energy loss and local deformation.The applicable scope of the modified formula is:impact mass between 193.35 and 920.00 kg,impact velocity between 3.96 and 14.48 m/s.for sensitive factor,when both ends are fixed,the confinement factor is between 0.500 and 2.0;when the two ends are simply supported,the confinement factor is between 0.500 and 1.617;when the ends are fixed and simply supported,the confinement factor is between 0.500 and 1.307.The samples were expanded by means of numerical simulation to verify the accuracy of the formula,and the results of the formula were compared with those of simulation.The results show that the proposed modified formula exhibits reasonable accuracy with errors within 10%.