纤维金属层板单搭连接二次弯曲影响因素分析

Analysis of Influencing Factors for Secondary Bending of Fiber Metal Laminates Single Lap Joint

纤维金属层板单搭连接不可避免的会产生二次弯曲效应,而二次弯曲对层板单搭连接强度和疲劳寿命有不同程度的削弱。为了减缓层板单搭连接所产生的二次弯曲效应,采用有限元模型和中性轴模型研究层板装夹方式、层板厚度、外载荷和层板刚度折损对层板单搭连接二次弯曲效应的影响,为层板单搭连接的设计提供建议和依据;结果表明:层板单搭连接有限元模型和中性轴模型都能够很好的预测纤维金属层板二次弯曲效应;对心装夹比偏心装夹对层板二次弯曲效应影响大;层板厚度增加减弱了层板连接处的弯曲应力,但其二次弯曲效应反而加重;外载荷的增加也能够弱化二次弯曲效应,但在偏心装夹情况下,其缓解二次弯曲能力更强;层板刚度折损加剧了连接件的弯曲程度,从而加剧了层板二次弯曲效应。

The secondary bending effects inevitably occur in the single lap joints of the fiber metal laminates,which can weaken the strength and fatigue life of the laminates in a certain extent.In order to slow down the secondary bending effects produced by the single lap joints of the laminates and provide help for the design,the effects of the clamping mode,the thickness of the laminates,the external loads and the laminates stiffness degradationare are studied by using the finite element model and the neutral line model.The results show that:both the finite element model and the neutral line model of the laminates can predict the secondary bending effects of the fiber metal laminates,and the effects of the eccentric clamping on the secondary bending behaviors of the laminates are large;The increase of the thickness of the laminates reduces the bending stresses at the joint of the laminates,but the secondary bending effects are more serious;The increase of external load can also weaken the secondary bending effects,especially in the case of eccentric clamping;The stiffness degradation of laminates increases the bending degree of the rivet joints,which aggravates the secondary bending effects of laminates.