The deformation of body components when a force is applied is a key factor in the safety of vehicle occupants. Low-speed crash tests are therefore carried out on bodywork components and complete vehicle front ends before typical high-speed tests are performed. Even loads generated at low-speeds provide relevant information, which is then channeled back into the design stage. In order to define the parameters for crash tests, static compression tests are performed under high loads so that damage initiation and propagation are detected.
This testing system is equipped with a large lower and smaller upper T-slotted mounting platform. Up to four load cells can be mounted flexibly on the lower plate, while three load cells can be attached to the upper plate. The four load cells are used to measure the axial force components of the attachment points of components. The total axial load can be measured by the three upper load cells, even if the component fails asymmetrically, thus resulting in a load applied eccentrically to the test axis. The example shows the load-deformation curve of bumpers being determined using this test setup.
To determine the load-deformation curve of large body components (in this case a vehicle door), a widened version of a ZwickRoell materials testing machine with two load cells (the force components are totaled) and a semi-cylindrical bending tool is used. Since the components do not fail symmetrically along the length of the -flexure test tool, a bending moment arises relative to the test axis. This presents no difficulty from a measuring point of view since the two load cells used are insensitive to bending moments. The upper test area is equipped with specimen grips and an extensometer for standard tensile tests on metals.