铝合金疲劳裂纹振动红外热成像检测研究

Study on vibrothermography detection of fatigue crack in aluminum alloy

航空铝合金经过多次使用存在紧密闭合型裂纹严重威胁飞行安全,以带有疲劳裂纹的7075铝合金为检测对象,利用超声振动做为振动红外热成像技术的激励源,通过多次调节功率、焊枪与平板之间预紧力和激励位置实现对铝合金板缺陷的识别,实验结果表明,振动热成像技术能检测出紧密闭合裂纹,同时发现检测效果受控于激励功率的影响,功率大振幅显著检测效果好,且功率较大的情况下预紧力对检测效果影响较大,功率较低时预紧力对检测效果小,最后发现在功率一定的情况下合理的调节预紧力和激励位置能使缺陷成像结果更加清晰。

Aviation aluminum alloy after many use were tightly closed type crack a serious threat to flight safety,with fatigue crack of 7075 aluminum alloy as test object,the use of ultrasonic vibration as vibration excitation source of vibrothermography,by adjusting the power,between welding torch and tablet pre-tightening force and incentive location,the recognition of defects of aluminum alloy plate is realized.The experimental results show that the vibration of thermal imaging technology can detect the tightly closed crack,also found that detection effect is controlled by driving power,the influence of large amplitude detection significantly effect is good.In addition,under the condition of high power,preload has a great influence on the detection effect,while under the condition of low power,preload has a small effect on the detection effect.Finally,it is found that reasonable adjustment of the preload and excitation position can make the defect imaging result clearer.