临界折射纵波探头声束特性的边界元分析与测量  

Boundary element analysis and measurement for beam profiles of critically refracted longitudinal wave probes

作　　者：卢超[1,2] 黎连修[2] 涂占宽[2] 

机构地区：[1]南昌航空大学无损检测技术教育部重点实验室,南昌330063 [2]中国铁道科学研究院金属及化学研究所,北京100081

出　　处：《仪器仪表学报》2008年第12期2570-2575,共6页Chinese Journal of Scientific Instrument

基　　金：铁道部科技研发计划(2007G040);南昌航空大学无损检测技术教育部重点实验室开放基金(ZD200729004)资助项目

摘　　要：与其他超声应力测量方法相比,临界折射纵波(LCR波)方法对应力场敏感,受材料组织结构效应影响小,在材料表面或近表面残余应力无损测量中具有突出的优势。本文应用边界元方法对LCR波探头发射的临界折射纵波的传播特性和声束特性进行分析并进行了实验测量。建立了IIW试块圆弧反射部分的三维边界元模型。通过数值分析,清楚显示了LCR波在IIW试块中的传播过程,给出了LCR波探头的主声束指向特性。计算结果为有关LCR波应力测量中声波能量有效渗透深度和能量层厚度的确定提供了理论依据。利用IIW试块实验测量了LCR波探头的声束特性,实验测量与数值分析结果符合得很好。本文的研究结果对研究厚板材料内部切向残余应力的LCR波测量方法具有指导意义。Compared with other ultrasonic methods, the critically refracted longitudinal （LCR） wave technique for surface and subsurface residual stress nondestructive measurement has prominent advantage, which is most sensitive to stress fields and least affected by material texture. The boundary element analysis and experiment measurement of LCR wave propagation characteristic and beam profiles are presented in this investigation. A 3D boundary element model of the IIW block arc reflector was completed. Through numerical analysis, the wavefront snapshots of the LCR wave propagated in the IIW block clearly illustrate the propagation mechanism, and the directivity characteristic of the main beam is obtained. Simulation results give the criterion of the effective penetration depth and effective layer width for LCR stress evaluation method. The beam profiles of the LCR probe were measured on the IIW block ; experimental measurement results and numerical analysis are in good agreement. The investigation result is really significant to the design of efficient probes for the internal residual stress measurement of thick plates based on the ultrasonic LcR wave method.

关 键 词：超声应力测量 临界折射纵波(LCR波) 声束特性 边界元方法 

分 类 号：O346.1[理学—固体力学] TN011[理学—力学]