Abstract: To determine the primary suspension dynamic and static stiffness of railway vehicle bogie, the test principle and method were proposed based on a new bogie test bench. The primary suspension and the secondary suspension were separated by a frame-fixing device, which was supposed to fasten the frame of the bogie. Forces along three directions were imposed respectively on the primary suspension, and the corresponding displacements were measured to calculate the stiffness. According to the calculated stiffness the spring quality and assembly relationship of the primary suspension were evaluated. For a certain metro trailer bogie, the dynamic and static stiffness of the primary suspension were measured by experiments. It is shown that differences between the measured static stiffness and the designed static stiffness of the primary suspension along the three directions are within allowed range of 10%. So the tested primary suspension of the bogie meets the designing requirements. The dynamic horizontal stiffness of the primary suspension is supposed to decrease with the increase in its corresponding frequency. However unlike 1# and 2# primary suspensions, which follow the principle mentioned above, the horizontal dynamic stiffness of 3# and 4# primary suspensions both fluctuated around the frequencies of 5.5 Hz and 8.5 Hz. This difference between the wheel sets is attributed to the assembly deviation of the wheels and axle box. Therefore, the assembly relationship of the primary suspension of the tested bogie should be appropriately adjusted.

Key words: railway transport, stiffness testing, bogie test bench, primary suspension