Abstract: Magnetorheological damper (MRD) is a first-rate device for semiactive control of vehicle suspension. However, the traditional MRD with complex inverse model and regulating process is difficult to be applied to the practice. In order to overcome these disadvantages, a new type of MRD paralleling with constant throttling orifices is proposed. If the current of winding is set to zero, the magnetorheological fluid (MRF) flow through both inactive inducing gap and constant throttling orifices, so the damping is minimum; if the current is set to the maximum value, the inducing gap is plugged by the activated MRF and works as a pressure limiter, so the fluid only flow though the constant throttling orifices until the MRF in the inducing gap is yielded, which means the damping is maximum. The mathematical model of the proposed damper is deduced to provide theoretic foundation for structure design and damping force analysis. The feasibility of this novel MRD is verified by magnetic circuit simulation and damping experiment. Especially, the proposed MRD is appropriate to combined with on/off control strategies because the complicate inverse model and control process may be avoided. In a word, the MRD paralleling with constant throttling orifices owns significant advantages for practical application.

Key words: damper, magnetorheological fluid, semi-active control, structure design