大跨度公路悬索桥涡振条件下驾驶员全身振动研究

Evaluation of whole body vibration of vehicle drivers on long-span highway suspension bridge experiencing vortex-induced vibration

作为大跨度悬索桥在服役期间最主要的风致振动灾害之一,涡振会显著降低桥上驾驶员的人体振动舒适度。文章开展了大跨度悬索桥在涡振条件下,车辆在桥上行驶过程中车内驾驶员全身振动及影响因素的研究。首先,基于传统的风-车-桥耦合振动分析理论,通过引入简谐涡激力模型模拟桥梁的涡振,利用ANSYS和MATLAB混合编程技术建立了大跨度公路悬索桥涡振条件下风-车-桥耦合振动模型。其次,提出了基于国际标准评价法ISO 2631-1∶1997(E)的人体全身振动评价方法,包含舒适度和晕动病的评价两个方面。然后,基于已建立的风-车-桥耦合振动模型和人体全身振动评价方法,以一座大跨度公路悬索桥为例,围绕舒适度和晕动病对涡振条件下桥上驾驶员的全身振动进行了评价并分析了影响因素,且在此基础上,进一步研究了基于晕动病的大跨度悬索桥的涡振限值。研究结果如下:对于驾驶员舒适度,路面粗糙度是其主要影响因素,即路面粗糙度的增加会显著降低驾驶员的舒适度。对于驾驶员晕动病,桥梁的涡振是其主要影响因素,即随着涡振振幅的增加,桥上驾驶员的晕动病评价指标呈线性增加的规律;而随着涡振频率的增加,桥上驾驶员的晕动病评价指标呈现出先增加、后减小的非线性变化规律。最后,基于驾驶员晕动病指标,文章提出了针对大跨度悬索桥可能发生的不同涡振模态对应的涡振限值。

As one of the most devastating wind-induced vibration problems of long-span suspension bridges during operation,vortex-induced vibration(VIV)could deteriorate the vibration serviceability of human body for drivers.This paper presents a study on the evaluation of whole body vibration of vehicle drivers and its influencing factors when travelling on long-span highway suspension bridge experiencing vortex-induced vibration.Firstly,the analytical framework for the wind-vehicle-bridge coupled vibration analysis considering the VIV of long-span suspension bridges is established,incorporating the simple harmonic vortex induced force model into the traditional wind-vehicle-bridge coupled vibration analysis theory.The analytical model is developed through hybrid programming technology of ANSYS and MATLAB.Secondly,an evaluation method of human whole body vibration based on international standard evaluation method ISO 2631-1∶1997(E)is proposed,which includes the evaluation of vibration serviceability of human body and motion sickness.Thirdly,the proposed evaluation framework is applied to a prototype long-span highway suspension bridge,in which the whole body vibration of vehicle drivers,as well as the influencing factors are analyzed.Subsequently,the allowable VIV magnitude of long-span suspension bridge is investigated based on the motion sickness.The results indicate that the road roughness is the main factor affecting the driver?s comfort and the deteriorate of road roughness could lower the level of driver?s comfort.As for the driver?s motion sickness,the VIV of the bridge is the main influencing factor.With the increase of VIV amplitude,the evaluation index of driver?s motion sickness increases linearly.With the increase of VIV frequency,the evaluation index of driver?s motion sickness first increases and then decreases.Finally,allowable VIV magnitude of each possible VIV mode of long-span suspension bridge is proposed based on evaluation index of driver?s motion sickness.