Research On Monitoring Sensor Layout Of Cable Structure Of Cable-stayed Bridge Based On Damage Sensitive Analysis

The cable sensor system is used to determine the real-time damage of existing bridges,truly obtain structural overall and local information,provide early warning at special moments,reduce loss and waste in human resources and financial resources,and reduce the interference of error information to the processing system.The long life of the bridge is of great significance.Bridge health monitoring is a method that can effectively obtain bridge structural information and identify bridge damage.It can provide a scientific basis for bridge safety assessment and management decision-making.It has received extensive attention in recent years.When the cable is in the rust and fatigue state,the effective cross-sectional area of the cable will be reduced or even broken,leading to changes in the internal force of the main girder structure of the cable-stayed bridge and significant changes in the surrounding cable pull force,bringing about life and property unnecessary trouble.Damage to the cable will cause the bridge to fail to operate properly.In order to properly lay out the cable sensor,the following studies have been conducted:(1)Through the unity of the effective cross-sectional area,the influence of the cable damage at different positions on the bridge is analyzed under the condition of rust and fatigue damage;(2)Establish a finite element model and perform mechanical analysis through midas Civil;(3)By simulating cable corrosion,the influence of cable damage on the cable tension and the displacement of the main girder is analyzed,and the more sensitive cable is determined to determine the layout of cable force sensor;(4)For the fatigue damage of side spans and midspan cables,the dynamic characteristics of cable-stayed bridges under different working conditions and different orders are studied to determine the layout of acceleration sensors.Research shows that placing sensors at sensitive cables can reflect theimpact of cable corrosion on the system and is an important part of the bridge health monitoring system.Fatigue damage is the cumulative result of long-term structural damage and has a great influence on the dynamic characteristics of cable-stayed bridges.The study shows that under the influence of cable damage,the natural vibration frequency of the cable-stayed bridge will decrease,the long cable will affect the low-order frequency,and the short cable will affect the high-order frequency.When laying out the acceleration sensor,attention should be paid to the The long rope and short rope of the bridge.