It is repeatedly proved that any minor change in the parameters involved in the test set up of BIW Bending and Torsion Stiffness evaluation changes the final test results significantly.
The primary aim of the Physical Stiffness Tests, in the development stage of an Automotive Body is to ensure CAE co-relation. The setup for the physical test must therefore be designed such that the constraints match exactly with the ones in CAE. This will avoid any issues of correlating the test conditions. Any deviations in the test results between the two can then be studied separately.
At first, this paper analytically deals with the mounting points that should be used on the various vehicle body types based on the different types of suspensions they employ. Based on the theoretical conditions, a practical test set-up has been derived for testing the Bending Stiffness and the Torsion Stiffness separately.
The paper mainly deals with the various degrees of freedom that either need to be constrained or kept free to maintain appropriate load paths during the test. Guidelines to ensure correct fixture designs for the front as well as the rear mounting points are also included.