It is difficult to obtain accurate measurements of the dynamic characteristics exhibited by automotive steering columns. The difficulties are due in-part to the use of lubricated contact bearings which support the column during testing. These bearings introduce damping, hysteresis, non-linear stiffness and clearance/preloaded constraints on the column. These error sources then mask the true dynamic behavior of the column, thereby preventing a better understanding of the relationship between column design, manufacturing tolerances and column vibration. With this paper, we introduce the concept of a revolute compliant mechanism that can be used in place of contact bearings to support steering columns during dynamic tests. These mechanisms do not exhibit the non-linear damping/stiffness and non-repeatable errors found in contact bearings. As a result, they can be used to design equipment that is capable of taking test data which matches theoretical predictions to within 2%. Experimental results obtained with this equipment suggest (more study is needed to confirm this) that manufacturing errors may be responsible for up to 20–30% error in predicting vibration amplitudes of components within the column, but only 2% error in predicting steering wheel vibration amplitude. Understanding this tolerance-response relationship (via this test equipment) is a necessary first step in understanding and eliminating steering wheel nibble vibrations.

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