坐姿状态下人-结构相互作用体系水平振动特性

Horizontal Vibration Characteristics of Human-Structure Interaction System in Sitting Posture

针对人-结构系统水平振动问题,建立质量轻基频低的试验平台,研究人端坐于试验平台时该人-结构相互作用体系的水平振动特性.试验结果表明:自然端坐状态下,人体的不同朝向对结构的动力特性的影响不同.当人朝x向端坐时,结构多出一个振型频率,而基频恰好分布于两振型中间;而当人朝y向端坐时,结构仅有共振频率高于原结构基频.在研究中,人通常比较成质量块放在结构装置上,而事实上质量块对结构的振型阻尼比影响很小,人体能显著增大结构振型阻尼比.因此,不能将水平向自然端坐的人仅仅看作质量块,而应当成质量-弹簧-阻尼完整的体系.

Aiming at the system level of vibration structure,a low frequency light mass test platform was established to study the horizontal vibration of human-structure interaction system in sitting posture.The experimental results show that under the natural sitting state,the influence of different human orientations on the dynamic characteristics is different,when human orientation is xdirection,the structure has one more vibration frequency,and fundamental frequency locates just between two modes;when human orientation is y direction,only the structure resonance frequency is higher than the fundamental frequency of original structure.The human usually is simulated into a mass on structure,the influence of the mass on the modal damping ratio is slight,bur human can significantly increase the structural modal damping ratio,therefore the human under the natural sitting state cannot be regarded simply as a mass,but should be combined into the whole system of mass-spring-damping.