The automotive industry strives to use materials that both protect passengers and improve fuel efficiency. The VDA bend test attempts to determine the deformation behavior of a material during forming processes and/or crash loading. The results of this test can inform materials selection for processability while also keeping the highest safety standards intact.
In 2017 the VDA238-100 standard was updated with new, stringent requirements that would better reflect the behavior of the material and not the test fixture. These changes prompted a fundamental redesign of the VDA 3-Point Flexure Test Kit by ZwickRoell. The new design does not compromise overall test fixture stiffness even for thick sheet metal that require high test forces.
New requirements detailed in VDA238-100:2017 include
- Appendix A details a stiffness criteria and verification of anvil rollers under significant load.
- Requirement for frictionless (to the extent possible) support of the anvil rollers.
- Positioning of the anvil rollers under the die is refined and provided with tolerances.
- Change in the dimension and tolerances of the die.
- Revised formula for the angle determination from the movement of the die (now Appendix D)
- Optical measurement of the bending angle is permitted (Appendix E)
ZwickRoell’s testXpert III software delivers preprogrammed calculations to ensure reliable test results. Optionally available are a digital dial gauge for measuring the roller distance and a digital protractor for determination of the bending angle after testing. These options may be used with in combination with testXpert III software. After measurement, the values are transferred automatically to the test program and stored.