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Analysis on restrained torsion of composited box girder with corrugated steel webs[J].计算力学学报,2020,37(6):709~714

Analysis on restrained torsion of composited box girder with corrugated steel webs
Analysis on restrained torsion of composited box girder with corrugated steel webs

DOI：10.7511/jslx20200112003

 作者 单位 E-mail 孙成成 兰州交通大学 土木工程学院, 兰州 730070 张元海 兰州交通大学 土木工程学院, 兰州 730070 zyh17012@163.com

波形钢腹板箱梁相比于传统混凝土箱梁其扭转效应更为明显，为了更加合理地分析其约束扭转效应，在乌曼斯基第二理论的基础上考虑波形钢腹板的手风琴效应及顶底板对腹板的约束作用，通过截面等效的途径，推导了约束扭转正应力和二次剪应力的计算公式，数值算例和ANSYS有限元分析验证了所推导公式的正确性。引入正应力系数反映约束扭转正应力与弯曲正应力的占比关系，引入剪应力系数反映二次剪应力对扭转总剪应力的影响程度。结合数值算例，详细分析了悬臂板宽度和波形钢腹板厚度变化对应力系数的影响规律。研究结果表明，偏心集中荷载作用下，扭转翘曲正应力可达到弯曲正应力的45%，波形钢腹板上下两端区域内的约束扭转正应力可达到弯曲正应力水平，二次剪应力可达到扭转总剪应力的52%，减小悬臂板宽度和增大波形钢腹板厚度可显著降低二次剪应力。

Compared with a traditional concrete box girder,a box girder with corrugated steel webs displays an obvious torsional effect.In order to analyze the torsional constraint of the box girder with corrugated steel webs more reasonably,the accordion effect of the corrugated steel webs and the constraining effect of the top and bottom flanges are considered.On the basis of Umanskii’s second theory,the formulas for normal stress and the secondary shear stress are derived through section equivalence.The correctness of the formulas is verified by the ANSYS finite element analysis.The normal stress coefficient is introduced to reflect the relative relationship between the torsional normal stress and the bending normal stress,and the shear stress coefficient is introduced to reflect the influence of secondary shear stress on total torsional shear stress.Through numerical examples,the influence of the cantilever flange width and the thickness of corrugated steel web on the stress coefficients is analyzed in detail.The results show that under an eccentric concentrated load,the torision-induced normal stress can reach 45% of the bending normal stress,and the torsion-induced normal stress in the upper and lower ends of the web can reach the bending normal stress level.The secondary shear stress can reach 52% of the total torsional shear stress,and can be significantly reduced by reducing the cantilever flange width and increasing the web thickness.