基于随机等价线性化法的悬浮隧道锚索随机振动研究

摘要

为了得到悬浮隧道锚索在随机环境激励作用下的响应，建立了悬浮隧道锚索非线性随机振动方程，并在方程中考虑了锚索的垂度效应，随后采用随机等价线性化法对随机激励作用下锚索的振动响应进行了分析。研究结果表明：在零均值高斯白噪声环境激励作用下，锚索的跨中位移和速度均方根响应经过一定时间后将趋于定值，位移和速度的互相关函数趋于零；锚索的阻尼比越大，锚索跨中横向位移均方根响应越小；激励的功率谱密度强度越大，锚索跨中横向位移均方根响应越大；由于水体阻尼力的存在，悬浮隧道锚索的位移和速度均方根响应比空气中锚索的响应大幅减小。%To study the random vibration response of a submerged floating tunnel's tether subjected to random ambient excitation,a non-linear random vibration equation of the tether was established considering the effect of tether sag.Subsequently,the vibration response of the tether was analyzed by means of the stochastic equivalent linearization method.The results indicated that the mid-span displacement and velocity root mean square responses of the tether to zero-mean Gaussian white noise excitation tend to stable values after a certain period of time,while the cross-correlation function between mid-span displacement and velocity tends to zero;the mid-span displacement root mean square response of the tether decreases with increase in the tether's damping ratio,whereas it increases with increase in the power spectral density of the excitation;due to the existence of the water damping force,the displacement and velocity root mean square responses of the tether decreases greatly compared with those of the tether in air.