考虑梗腋影响的波形钢腹板组合箱梁剪力滞效应研究

Shear lag effect theory and parameter analysis of composite box girder with corrugated steel webs considering the influence of haunch

考虑梗腋在波形钢腹板组合箱梁剪力滞效应的影响,通过剪力流公式定义了考虑梗腋影响的修正系数,运用变分法得到对应的微分方程,然后求出简支波形钢腹板组合箱梁在集中荷载作用下的剪力滞系数计算公式,采用数值模拟进行对比验证。最后通过调整梗腋尺寸参数,研究梗腋形状变化对剪力滞效应的影响。结果表明,考虑梗腋影响后的理论计算结果与有限元结果吻合较好;波形钢腹板组合箱梁的剪力滞效应现象随着梗腋影响系数的增大而减小;考虑梗腋影响的波形钢腹板组合箱梁剪力滞系数较未考虑情况大幅度降低,在集中荷载下剪力滞效应系数减小约10%;当梗腋宽度与上翼板宽度的比值大于0.5时,对剪力滞效应的影响变化较小,梗腋高度为其宽度的0.16~0.19倍时对剪力滞效应影响最大。

Considering the influence of the haunch on the shear lag effect of the corrugated steel web composite box girder,the correction coefficient is defined through the shear flow formula,the corresponding differential equation is obtained by the variational method,and then the calculation formula of the shear lag coefficient of the simply supported corrugated steel web composite box girder under a concentrated load is obtained,which is verified by numerical simulation.Finally,by adjusting the size parameters of the stem axil,the influence of the change of the stem axil shape on the shear lag effect is studied.The results show that the theoretical calculation results considering the influence of stem axillary are in good agreement with the finite element results.The shear lag effect of the corrugated steel web composite box girder decreases with the increase of haunch influence coefficient.The shear lag coefficient of the corrugated steel web composite box girder considering the influence of haunch is significantly lower than that without consideration,and the shear lag effect coefficient is reduced by about 10%under a concentrated load;When the ratio of the haunch width to the upper flange width is greater than 0.5,the influence on the shear lag changes little,and the influence on the shear lag is the largest when the haunch height is 0.16~0.19 times of its width.