残余应力对碳纤维增强压弯H型钢弹塑性稳定性的影响研究

INFLUENCE OF THE RESIDUAL STRESS ON THE ELASTIC-PLASTIC STABILITY OF H-SHAPED STEEL MEMBERS WRAPPED BY CFRP UNEDER AXIAL COMPRESSIVE LOAD AND BENDING MOMENT

建立轴压和弯矩共同作用下碳纤维增强H形截面构件绕强轴失稳时极限荷载的计算公式。通过弹塑性有限元法并结合非线性屈曲理论,进行了压弯荷载共同作用时碳纤维增强钢构件和考虑残余应力影响下钢构件的屈曲分析。当给定弯矩仅在某一范围内时,考虑残余应力的CFRP增强钢构件的极限承载力相比CFRP增强完善条件下的钢构件极限承载力相比要低很多。当给定弯矩超出此范围时,前者要略高于后者。受残余应力影响的碳纤维增强压弯构件极限承载力始终比未增强完善钢构件的限承载力高,表明构件可以通过碳纤维增强来弥补残余应力所导致的构件承载力损失,充分体现了碳纤维良好的增强效果。

The analytical expressions of the ultimate buckling load about the neutral axis of the maximum moment of inertia for an H-shaped member wrapped by carbon fiber are derived.Using the elastic-plastic finite element method and the theory of nonlinear buckling,the impact of residual stress and non-residual stress in an H-shaped steel member wrapped by carbon fiber reinforced polymer(CFRP)under axial compressive load and bending moment is analyzed.When the given bending moment is within a certain range,the ultimate strength of CFRP reinforced steel members considering residual stress is much lower than that of CFRP reinforced steel members.However,when the given bending moment exceeds this range,the former is slightly higher than the latter.The ultimate strength of a CFRP reinforced compression-bending member affected by residual stress is always higher than that of steel members that is not reinforced and perfected.It also shows that CFRP wrapping can reduce the loss of strength caused by residual stress,which fully demonstrates the good strengthening effect of carbon fiber.