微小构件残余应力分布的超声无损检测技术

发布时间：2018-06-13 10:18

本文选题：微小构件 + 残余应力　；参考：《北京理工大学》2016年硕士论文

【摘要】：细管、螺栓、小直径螺钉和小齿轮等微小构件在日常生活中应用广泛,这些构件在生产和使用过程中不可避免地产生残余应力集中现象而使抗疲劳寿命缩短。为了确保这些构件使用过程中的安全,需要对其关键部位进行残余应力检测。残余应力的存在会影响超声波在材料中的传播速度,在有应力的固体材料中,声速的变化可以反映应力的变化,声速的变化可以通过检测声时来显示,根据这一规律,可以通过测量出声时的大小得到残余应力的大小。针对细管、小齿轮残余应力的检测,本文提出了一种基于临界折射纵波的残余应力检测方法,采用一发一收模式通过声时的变化检测细管和小齿轮的残余应力,针对螺栓和小直径螺钉残余应力的检测,本文提出了一种基于横波和纵波相结合的残余应力检测方法,采用自发自收模式通过检测超声波在螺栓和小直径螺钉中传播的时间检测螺栓等构件的轴向残余应力。本文搭建了基于临界折射纵波检测方法的一发一收超声纵波残余应力检测装置和基于横波和纵波结合检测方法的自发自收超声横纵波轴向残余应力检测装置,通过对细管、螺栓、小直径螺钉和小齿轮残余应力检测的实验,验证了超声检测方法的可行性。并详细分析了换能器入射角度、构件材质、构件厚度、传感器间距、声速温度性、温度、构件曲率、表面粗糙度以及耦合剂等因素对残余应力检测的影响,通过分析和实验提出了相应的补偿技术减小误差,提高检测结果的准确性。
[Abstract]:Thin tubes, bolts, small diameter screws and pinions are widely used in daily life. The residual stress concentration is inevitable in the production and use of these components, which shorten the fatigue life. In order to ensure the safety of these components, it is necessary to detect the residual stress in the key parts. The existence of residual stress will affect the velocity of ultrasonic wave propagation in materials. In solid materials with stress, the change of sound velocity can reflect the change of stress, and the change of sound velocity can be shown by detecting sound time, according to this rule, The magnitude of residual stress can be obtained by measuring the magnitude of sound time. In this paper, a method based on critical refraction longitudinal wave is proposed to detect the residual stress of thin tube and pinion gear. The residual stress of thin tube and pinion is detected by the change of sound time in the mode of one source and one take-up. For the residual stress detection of bolts and small diameter screws, a new method based on the combination of S-wave and P-wave is proposed in this paper. The axial residual stress of bolt and other components was detected by the time of ultrasonic wave propagation in bolts and small diameter screws. In this paper, an ultrasonic residual stress detection device based on critical refraction longitudinal wave detection method and a spontaneous self-retractive ultrasonic longitudinal wave axial residual stress detecting device based on the combination of shear wave and longitudinal wave are built. The experiment of bolt, small diameter screw and pinion residual stress test verifies the feasibility of ultrasonic testing method. The influence of the incident angle of transducer, component material, component thickness, sensor spacing, sound velocity temperature, component curvature, surface roughness and coupling agent on residual stress measurement are analyzed in detail. Through the analysis and experiment, the corresponding compensation technique is put forward to reduce the error and improve the accuracy of the detection results.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG115.285

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