单箱双室钢底板波形钢腹板组合箱梁扭转性能分析

Analysis on torsion performance of single-box twin-cell composite box girder with corrugated steel webs and steel bottom plates

为研究单箱双室新型钢底板波形钢腹板组合箱梁的扭转性能,基于乌曼斯基第二理论推导了箱梁的扭转微分方程和应力公式,结合纯扭转试验和有限元模型,检验理论公式的正确性.分析不同因素对箱梁扭转性能的影响,对比新型梁与传统混凝土底板梁的性能变化.结果表明,同一测点理论值、有限元值与实测值吻合较好,差值大多在30%以内,整体变化规律一致.横隔板和加劲肋的一般布置方式对新型梁的有效抗扭刚度影响较小;当高宽比达到0.4时,截面正应力会产生明显变化.相对于传统梁,新型梁抗扭刚度减小8.58%,截面约束系数减小58.44%;相同扭矩下,新型梁跨中扭转角增大13.6%,最大扭转双力矩减小69.66%,2种箱梁正应力区别明显,剪应力相差较小.

To study the torsion performance of new single-box twin-cell composite box girder with corrugated steel webs,the torsion differential equation and the stress formula of the box girder were derived based on the Second Theory of Umanskii.Combined with the pure torsion test and the finite element model,the correctness of the theoretical formula was verified.The influence of different factors on the torsion performance of the box girder was analyzed.The performance changes of the new beam and the traditional beam were compared.The results show that the theoretical values,the finite element values and the measured values of the same measuring point are in good agreement.The difference values are mostly less than 30%,and the overall change laws are the same.The general arrangement of the diaphragm and the stiffener has little influence on the effective torsional stiffness of the new beam.When the ratio of the height to the width reaches 0.4,the normal stress of the section changes obviously.Compared with the traditional beam,the torsional stiffness of the new beam decreases by 8.58%,and the section constraint coefficient decreases by 58.44%.With the same torque,the mid-span torsion angle of the new beam increases by 13.6%,and the maximum torsional double torque decreases by 69.66%.The difference of the normal stress between the two kinds of the box girders is obvious while the difference of the shear stress is smaller.