弯-剪-扭复合作用下考虑扭转翘曲的U形薄壁混凝土梁设计方法

Design Method of U-shaped Thin-walled Concrete Girders under Combined Effect of Bending-Shear-Torsion Considering Torsional Warping Effect

基于弯-剪-扭复合作用下U形薄壁混凝土梁的试验和数值模拟参数分析研究成果,提出U形梁约束扭转内力翘曲弯矩Mω和翘曲扭矩Tω的等效方法,进而提出弯-剪-扭复合作用下考虑扭转翘曲的U形薄壁混凝土梁设计方法。对考虑扭转翘曲、不考虑扭转翘曲2种情况下的设计内力和计算极限荷载的结果进行对比分析。结果表明:2种情况下所得到的设计内力在内力类别和数值上均差异显著;当扭弯比较小(约小于1∶8)时,忽略扭转翘曲时得到的极限荷载计算值偏大;当扭弯比较大(约大于1∶8)时,忽略扭转翘曲时得到的极限荷载计算值偏小。

Based on the experimental and numerical simulation results of U-shaped thin-walled concrete girders under combined actions of bending,shear and torsion,an equivalent method of warping moment Mωand warping torque Tωis proposed,and then a design method of U-shaped thin-walled concrete girders under effect of combined bending-shear-torsion considering torsional warping is proposed.The differences on internal forces and calculated ultimate loads are analyzed between cases of considering and non-considering torsional warping respectively.The results show that there are significant differences both on the types and values of internal forces;when the torque-bending moment ratio is small(about<1∶8),the non-warping calculated ultimate load is relatively larger,and when the torque-bending moment ratio is large(about>1∶8),the non-warping calculated ultimate load is relatively smaller.