Noncontact Bending and Torsional Stiffness Estimation Model for Automobile Frames Based on 3D Displacements

In this study, a noncontact bending and torsional stiffness estimation model for automobile frames is proposed. The deformed shapes of an automobile frame during bending and torsional loading tests were determined based on the 3D displacements from motion capture system (MCS). The measurement results from the system and existing sensors, such as linear variable differential transformers (LVDTs) and an inclinometer, were compared. The vertical displacements from a total of 30 markers measured by the MCS can be used to define the 3D bending and torsional deformed shapes of the automobile frame. The test results confirmed that the stiffness estimation model based on MCS facilitates more detailed and accurate estimation of stiffness of the automobile.