在不同的激振频率、不同激励电流下，对一种带旁通孔的磁流变减振器在MTS平台上进行阻尼力测试。该减振器的活塞具有不受磁场影响的三个旁通孔。实验结果表明，该减振器可以在较宽的激振速度范围内与激振速度近似成线性关系，随着激励电流和激振频率的增大，该减振器的阻尼力逐渐增大。并且在各激振频率下，阻尼力均没有出现突增现象；但是当阻尼力达到一定数值后，阻尼力基本不再受活塞速度影响。这些特性可以有效提高车辆乘坐舒适性。通过引入液体的局部水头损失，对磁流变液分别采用宾汉模型和艾林模型，计算出减振器的阻尼力理论值。经比较，采用艾林模型得到的理论值与实验值吻合得更好。在各工况下，行程中间位置的阻尼力理论值与实验值最大误差小于2.3%。若忽略液体的局部水头损失，阻尼力的理论值与实验值的误差将增大。该结果表明，引入局部水头损失及采用艾林模型进行阻尼力理论计算是合理的，研究结论可以对减振器的设计和优化提供参考。

The damping force of a novel magneto-rheological (MR) damper was tested on MTS system in different excitation frequencies and different currents. The MR damper has three bypass holes in the piston. Experiment results indicate that the damping force has a quasi-linear relation with excitation velocity in a much broader range. Damping force also increases with applied currents. No damping force spurt at each excitation frequency. Damping force is sensitive to excitation frequencies. These characteristics make vehicles better riding comfort. At last, damping force was calculated adopting the local head loss with Bingham model or Eyring model. Damping force calculated by Eyring model matches better with experimental data. Maximum deviation of damping force in each operating condition is less than 2.3%. And if no local head loss was adopted, the damping force by calculation deviates far from experiment data. These results indicate that the calculation is reasonable and will contribute to design and optimization of MR damper.