Performance Analysis of Laminated Rubber Base Isolator-Based Secondary Suspensions Under Deflated Air-Spring

In a railroad wagon, the vertical excitation on the wheels originated from the track irregularities; the air spring model is reliably used to restrict these abnormal vibrations at a required level and improve traveler comfort. When air springs deflate during running, too much vibration occurs and the ride is less comfortable, which are common complaints among high-speed rail operators. In the situation that the air spring deflates, the laminated rubber spring acts as a temporary emergency spring to reduce the dynamic load. An approximation method for measuring laminated rubber’s static stiffness is presented and examined the effect on the air suspension. In this study the equations of motion for the pitch, roll, and the bounce motion of the bogies and the car’s body were developed with deflated state of air spring to systematically study the effect of deflated air spring on the ride comfort of passengers. The study show that passengers’ ride comfort was predicted accurately by the proposed model. It also observed that in the presence of a laminated rubber spring, the air spring’s dynamic stiffness is moved to higher frequencies. The air spring’s dynamic stiffness is reduced at lower frequency when the diameter of the surge pipe is increased. According to the results of the research, the vehicle’s speed should be reduced while the air spring is deflated in order to keep the passengers’ comfort.