【摘要】 为了研究有机硅密封胶(DB527)粘接的对接试件在单轴拉伸循环载荷作用下的疲劳性能和棘轮效应,分别分析了应力幅值、平均应力和不同加载历史对粘接试件的棘轮应变、棘轮应变率以及疲劳寿命的影响。研究结果表明:应力幅值变化对粘接结构的疲劳寿命和棘轮应变影响很大,随着应力幅值增大,滞环面积增加,稳定阶段棘轮应变随之增加,棘轮应变率也增加;而且粘接材料随着应力幅值的增加出现循环软化现象。在不同的平均应力情况下,随着平均应力的增加,应力-应变曲线变宽,棘轮应变也明显增加,棘轮应变率呈S形的增长趋势。两种情况下粘接结构的疲劳寿命,都随之增加而下降。更多还原

【Abstract】 In order to investigate the uniaxial ratcheting and fatigue failure behaviors of silicone adhesive(DB527)bonded specimens under uniaxial tensile cyclic loading,the effects of stress amplitude,average stress,different loading history on the ratcheting strain,ratcheting strain rate and fatigue life were analyzed respectively. The research results showed that stress amplitude had great influence on the fatigue life and ratcheting strain of the adhesive bonded structure. The hysteresis area,ratcheting strain and ratcheting strain rate all increased with the increasing of stress amplitudes. Furthermore,the cyclic softening phenomenon of bonded material occurred with the increasing of stress amplitude. Under different average stress conditions,with the increase of average stress,the stress-strain curve became wider,ratcheting strain also increased significantly,and ratcheting strain rate showed a S-shaped growth trend. In both cases,the fatigue life of bonded structures decreased with the increase of stress amplitude.更多还原