This paper presents the parameter identification of a vehicle moving on a multispan continuous bridge deck modeled as a continuous beam based on dynamic response sensitivity analysis. This technique is for the monitoring of "road-friendliness" of vehicles using the highway pavement. The moving vehicle is modeled as a single degree-of-freedom system comprising three parameters, a two degrees-of-freedom system comprising five parameters, or a four degrees-of-freedom system comprising 12 parameters. The modified beam functions are used to calculate the response of the continuous bridge. Starting with an initial guess on the unknown parameters, the identification can be realized based on least-squares method and regularization technique from measured strain, velocity, or acceleration measurement from as few as a single sensor. Simulation studies and experimental results indicate that the identified results are acceptable, and the responses reconstructed from the identified parameters agree well with the measured responses.

Vehicle Condition Surveillance on Continuous Bridges Based on Response Sensitivity

SUMMARY This work analyses the dynamic behavior of a motorcycle front suspension equipped with passive sequential hydraulic dampers, in some operative situations. The dampers, with non-linear and asymmetric characteristics, may be regulated in six different ways. Using experimental elasticity and damping data as reference parameters, and a simplified two-degrees-of-freedom model, some dynamic simulations were carried out in order to define damping parameters for optimal comfort and safety.

A Method to Analyse the Dynamic Behavior of a Motorcycle Front Suspension Equipped with Sequential Dampers

SUMMARY The application of an actuator in the secondary suspension of a body-steered bogie vehicle without any yaw stiffness in both the primary and the secondary suspension has been studied. The improvements in ride quality are investigated when the actuator works in the active and the semi-active states. Without reducing stability, for American track standard class 6 track, the body acceleration rms is reduced by 33% when the actuator is in the active state; for a bump track input, a reduction of 11% is possible when the actuator is in a semi-active state, compared with passive suspensions.

Active and semi-active systems for optimisation of bogie vehicle primary and secondary suspensions in the lateral plane.

In this paper, the dynamics of a vibrator-controlled adaptive damper is simulated. Its potential in vehicle isolation improvement is demonstrated by a quarter car model. From the results obtained, it is known that after adding a vibrator- controlled flow valve to the conventional hydraulic damper, it is possible to achieve a desired frequency-dependent damping characteristics to provide a large damping at system resonance for the attenuation of the system resonant overshoot, but small damping at higher frequencies to guarantee a good isolation performance. The special feature of this adaptive damper lies in the fact that the damper can be constructed totally mechanically without electronics, which provides a practical way for industrial applications. (A)

Ye Lin

Papers

The dynamics of the vibrator-controlled active damper and its potentials in vibration isolation