The impact of damage parameters of rail transit steel spring isolators on dynamic response

In the structural context of urban rail transit systems, spring isolators are susceptible to stiffness reduction, damage, and sagging due to fatigue effects. The presence of concealed components can render their detection challenging during routine inspections. A vehicle-track coupled model was established using the finite element software ABAQUS. The model was validated using actual vibration data from a specific section of the Shenzhen Metro’s floating slab. A uniform design approach was adopted for the execution of parameter experiments on spring isolators under various conditions, including different levels of damage in terms of quantity, severity, and location. Through model simulation, the quantitative impact of these damage parameters on the vibration response of the floating slab was determined. The calculation results indicate that the location of damage to the spring isolators exerts the greatest influence on the acceleration and displacement of the floating slab, with respective impact weights of 50% and 49.3%. The impact of the number of damaged isolators is 28.4% and 27.9%, while the impact of damage severity accounts for 21.6% and 22.8%.It can be seen that the damage location of the floating slab has the greatest influence on its vibration response, followed by the number of damaged steel springs, and finally the damage degree of steel springs.