摘要
在研究船舶、潜艇等工程结构的低频振动时,通常可以将其简化为质量在截面内分布非均匀的梁结构,此质量偏心会引起弯-纵耦合。针对弯-纵耦合的质量偏心Timoshenko梁,推导了其截止频率的解析表达式;探讨了质量偏心对其纵振波、传播弯曲波及衰减弯曲波波数的影响规律;研究了三组波数下纵向/弯曲位移比随频率及质量偏心的变化。分析结果表明,质量偏心会降低梁的截止频率,偏心率越大,降低越明显;弯曲衰减波会在截止频率处转变为弯曲传播波;质量偏心使得非频散的纵向振动波转变为频散波;纵向振动与弯曲振动的耦合在质量偏心率或频率增大时,会进一步加强。
When studying low-frequency vibration of engineering structures,such as,ships and submarines,they can usually be simplified as a beam structure with non-uniform mass distribution in cross-section.This mass eccentricity can cause bending-longitudinal coupling.Here,aiming at a mass eccentric Timoshenko beam with bending-longitudinal coupling,the analytical expression of its cut-off frequency was derived to explore effect laws of mass eccentricity on its longitudinal vibration wave number,propagation bending wave one and attenuation bending wave one.The variation of longitudinal/bending displacement ratio with changes of frequency and mass eccentricity under 3 sets of wave numbers was studied.The analysis results showed that mass eccentricity can reduce cut-off frequency of beam,the larger the eccentricity,the more obvious the reduction;bending attenuation wave can change into bending propagation wave at cut-off frequency;mass eccentricity makes non-dispersive longitudinal vibration wave change into dispersive one;the coupling between longitudinal vibration and bending vibration can be further strengthened when mass eccentricity or frequency increases.
作者
王剑
袁秀峰
胡永彪
WANG Jian;YUAN Xiufeng;HU Yongbiao(School of Construction Machinery,Chang’an University,Xi’an 710064,China;Euro-crane(China)Co.,Ltd.,Suzhou 215211,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2022年第1期265-270,287,共7页
Journal of Vibration and Shock
基金
中央高校基金(300102259107)。
