考虑残余应力影响的蜂窝梁畸变屈曲性能研究

基于蜂窝梁残余应力的试验研究成果和普通工字钢梁的残余应力分布研究成果，给出了蜂窝梁的残余应力分布模型，并与已有试验研究结果对比，以验证该模型的正确性。通过分析梁的长度、翼缘厚度和宽度等对蜂窝梁畸变屈曲临界荷载的影响规律，进一步探索了残余应力对蜂窝梁畸变屈曲荷载的影响程度及简化考虑残余应力影响的计算方法。研究结果表明：翼缘宽度和厚度对蜂窝梁畸变屈曲临界荷载影响较大，而腹板厚度对蜂窝梁畸变屈曲临界荷载影响较小；提高钢材强度可在一定程度上提高蜂窝梁畸变屈曲临界荷载，但残余应力的影响程度会相应增大；提出采用折减系数Kd=0.85来计算蜂窝梁畸变屈曲荷载中的残余应力影响，该方法安全且简便，便于实际工程应用。

Research on Distortional Buckling of Castellated Beams with Residual Stress Effects Taken into Consideration

Based on the experimental research results of the residual stresses of the castellated beams and the related research results of the residual stresses distribution in I-shaped beams, a residual stresses distribution model has thus been proposed for castellated beams, with its validity verified by comparing it with existing experimental results. An investigation is made on the influence of such key factors as the length, the thickness and width of the flange on the distortional buckling load of castellated beams, to be followed by a further exploration conducted on the influence of residual stress on the distortional buckling load of castellated beams as well as the means to simplify the calculation method with the residual stress effects taken into consideration. The results show that the width and thickness of flanges have great influences on the distortional buckling load of castellated beams, while the effects exerted by web thickness is relatively small. An increase in steel strength helps to imrprove the distortional buckling load to a certain degree, but with a corresponding increase in residual stresse effects. The proposed method, which adopts a reduction coefficient Kd=0.85 to calculate the residual stress effects, is good in security performance and easy to handle, which is convenient for practical engineering application.