UC14 on Biaxial Fatique Testing
November 05th 2019
They are taking the road to the lab: Users deliberate upon biaxial fatigue strength tests for passenger car and truck wheels
In recent years there have been major changes in the life cycle testing of vehicles or individual components: Thanks to state-of-the-art testing equipment today a few hours in the laboratory are sufficient for life cycle testing whereas previously test drives on the road taking a couple of days were necessary for this purpose. This development continues as the UC 14 -Users Conference on Biaxial Fatigue Testing on November 5th 2019 in Darmstadt showed. More than 50 scientists and users from Europe, China and the USA met at the Fraunhofer Institute for Structural Durability and System Reliability LBF for the 14th Users Conference on Biaxial Fatigue Testing of wheels and wheel hubs. Thanks to a wide range of development and testing activities in the field of wheel testing and approval, the institute was able to establish itself as a technology leader. Today the testing technology is known and accepted on a worldwide basis. It has been established as the international standard for more safety in vehicle construction. Besides it shortens the development times for new products.
The 14th Users Conference on Biaxial Fatigue Testing with scientists, manufacturers of passenger cars and commercial vehicles as well as suppliers was dedicated to various anniversaries. The biennial user conference itself has been in existence for 26 years now, so its 25th anniversary was celebrated in 2018. Furthermore, the Fraunhofer Society has turned 70, the organizing Fraunhofer Institute LBF celebrated its 80th anniversary in 2018, and the ZWARP technology has been around for over 30 years.
The international meeting, organized by the Fraunhofer–scientists, is known as a forum to discuss new developments in the market for testing and inspection technologies as well as trends in testing and manufacturing technologies with industry experts. Due to the different anniversaries, this year's conference was a good occasion to exchange ideas concerning several questions: In which direction will the technology develop, what are the future requirements of this technology and why is it beneficial to further develop the biaxial fatigue tests after so many years of application? An active discussion among the participants, guest contributions from partners who had only recently begun to use the ZWARP technology and from partners who have been using it almost since its introduction provided the required answers. A contribution on the development of a method to transfer wheel forces from road load data acquisition into local stress collectives on rotating components of the wheel head arouse particular interest.
The Fraunhofer LBF is considered as the pioneer in the multi-axial life cycle testing of vehicle wheels. In 1982, scientists at the institute put the biaxial wheel/hub test rig (ZWARP) into operation for the first time. At that time, it was a novel device for examining vehicle wheels under biaxial load. In 1984 a patent for road vehicles and in 1987 a patent for rail vehicles were filed and these technologies were subsequently sold under license to customers. At www.zwarp.fraunhofer.de/en.html the Fraunhofer LBF created a website with in-depth information about biaxial wheel/hub testing (ZWARP). Today, wheel road simulators of this type are used on a worldwide basis to shorten development times in the automotive industry and to test safety components such as wheels and wheel hubs.