杆中导波声弹性效应分析与数值模拟  

Numerical simulation and sensitivity analysis of acoustoelastic effect for guided wave in bar

作　　者：鲁珊珊[1] 吴英思[2] 刘飞[2] LU Shanshan;WU Yingsi;LIU Fei(Inner Mongolia Technical College of Mechanics and Electrics,Hohhot 010070,China;College of Mechanical and Electrical Engineering,Inner Mongolia Agricultural University,Hohhot 010018,China)

机构地区：[1]内蒙古机电职业技术学院,呼和浩特010070 [2]内蒙古农业大学机电工程学院,呼和浩特010018

出　　处：《应用声学》2018年第4期469-474,共6页Journal of Applied Acoustics

基　　金：国家自然科学基金项目(11662013)

摘　　要：大型钢结构在役应力检测意义重大,基于超声导波声弹性效应进行应力检测具有潜在的优势。该文基于等效弹性常数法研究了杆中超声导波的声弹性效应。通过计算Q235钢结构构件钢杆的频散曲线,确定了检测频率范围,并对不同工作应力状态下L(0,1)、F(1,1)与T(0,1)模态的群速度值进行了理论分析与数值模拟。结果表明:L(0,1)模态较适合于钢杆轴力检测,F(1,1)、T(0,1)模态声弹性效应较弱,不适合于应力检测;L(0,1)模态的声弹性效应随着频率的增加而减弱;通过理论分析与有限元计算对声弹性效应的验证都与波结构轴向位移对声弹性效应的判断得到了较好的吻合。A new significant method of online stress monitoring based on acoustoelastic theory for cylindrical guided wave was proposed aim at the deficiency of steel structure online stress monitoring.The disperse curves of?20 Q235 steel bar were calculated,the frequency ranges fit for acoustoelastic detection of cylindrical guided wave were optimized.According to acoustoelasticity motion equation and Pochhammer frequency equation,the group velocities of longitudinal L(0,1)mode,flexural F(1,1)mode and torsional T(0,1)mode in different stress level were calculated and simulated by theoretical equation and finite element software,and the acoustoelastic coefficients were obtained.The results show that longitudinal L(0,1)mode guided wave is fit for acoustoelastic axis stress monitoring,flexural F(1,1)mode and torsional T(0,1)mode are weak in acoustoelastic effect.Acoustoelastic effect of longitudinal L(0,1)mode is decreasing with the increasing of frequency.The results of theoretical and finite element simulation are consistent well with axial displacement of mode shapes for acoustoelastic effect.

关 键 词：等效弹性常数 柱面导波 声弹性效应 应力检测 频散 

分 类 号：TU378[建筑科学—结构工程] TB132[理学—物理]