钢管塔锻造法兰受压性能试验研究

EXPERIMENTAL RESEARCH ON COMPRESSIVE PERFORMANCE FORGED FLANGE OF STEEL TUBE TOWERS

对4组12个足尺不等管径对接法兰进行了轴心受压及偏心受压试验,研究了不等管径对接法兰在不同强度级差加载时的受力性能。结果表明,每组3个试件的受力机理和破坏特征基本一致,大小管径对接法兰的变形主要集中在小管径一侧。试验中未发生法兰和对接焊缝的破坏,法兰及焊缝的承载力满足设计要求。试件由于靠近刚性法兰加劲肋处钢管鼓曲而破坏,其极限承载力超过承载力设计值的35%~54%。偏心受力会一定程度地降低试件的承载能力,但影响较小,基本在10%以内。对试验试件进行了非线性有限元分析,明确了法兰的破坏机理,了解了法兰的极限承载力。结果表明:受压状态下,对于不等管径法兰连接,带颈锻造法兰由受压为主逐渐转变为受弯为主,导致法兰颈部变坡提前进入屈服,降低了试件的承载力。

The axial compression and eccentric compression tests were conducted on a total of 12 full-scale butt flange joints with unequal diameter in four groups,and the mechanical properties of the butt flange joint with unequal diameter were studied for different strength grade differences.The results showed that the mechanical mechanism and failure characteristics of three specimens in each group were the same,and the deformation of the flange joint was concentrated on smaller diameter tube.The failure of flange and butt weld was not found,the bearing capacity of flange and weld could meet the design requirements.The specimen failed due to the plastic buckling of steel pipe near the rigid flange stiffeners,and the ultimate bearing capacity exceeded 35%~54%of the design value of bearing capacity.Eccentric load would reduce the bearing capacity of the specimen,but the effect was less than 10%.Based on the nonlinear finite element analysis,the failure mechanism of flange was confirmed,and the ultimate bearing capacity was studied.The resulted showed that the compression was transformed into the bending for the unequal diameter forged flange connection with neck,which results in premature yielding of variable slope of the neck flange and reduced the bearing capacity of the specimen.