This standard is applicable to measurement of natural frequency and damping ratio of various biaxial automotive suspension systems. The measurement parameters include natural frequency and damping ratio of vehicle body (i.e. sprung weight) and natural frequency of wheels (i.e. unsprung weight). The three parameters are the basic data for analysis of the vibration characteristics of suspension system and for research and evaluation of automotive ride comfort.
1 Test Conditions
1.1 The test is carried out on automobile under full load. No-load test may be added as required. The gross weight of automobile and weights of front and rear axles shall be weighed before the test.
1.2 Suspension elastic element, vibration damper and bumper block shall comply with the technical provisions. Tests with vibration damper and bumper block removed may be added as required.
1.3 The tyre pattern shall be intact and the tyre pressure comply with the values specified by technical provisions.
