传播衰减法测阻尼的边界条件研究  

STUDY ON BOUNDARY CONDITION IN MEASURING DAMPING WITH PROPAGATION-ATTENUATION METHOD

作　　者：盛美萍[1] 张政[1] 王敏庆[1] 陈晓利[1] 

机构地区：[1]西北工业大学航海学院,西安710072

出　　处：《振动与冲击》2006年第6期135-138,共4页Journal of Vibration and Shock

基　　金：新世纪优秀人才计划(编号:NCET-04-0959);国家自然科学基金(编号:50375121)资助项目

摘　　要：实际工程结构在受激振动时,由于边界反射的影响,结构上振动响应远比无反射的无限大结构振动响应更为复杂。利用传播衰减法测量梁结构阻尼应考虑边界反射等影响。研究表明:远场条件与赫姆霍兹数有关,而边界条件与赫姆霍兹数、测试误差限等因素有关。对于梁结构阻尼的传播衰减法测试,合理的远场条件是kx 5,而合理的边界条件是kd-1ηlnT2。The vibration response of an excited practical project structure is much more complex than that of an infinite structure with no reflection,it's due to the boundary reflection effect.Thus,the boundary reflection effect and other effects must be considered during using the propagation-attenuation method to measure damping of a beam.It is found that the far-field condition of measurement is determined by Helmhotz number,while the boundary condition of measurement is related to Helmhotz number and allowable measuring errors.An experiment is carried out and it is testified that the reasonable far-field condition is that kx≥5 while the reasonable boundary condition is that kd≥-1ηlnT^2 during testing the beam damping with the propagation-attenuation method.

关 键 词：传播衰减法 阻尼 测试 

分 类 号：TH113.1[机械工程—机械设计及理论]