BiAx Wheel Test Technology (ZWARP)

Introduction

Wheels, hubs and bolts are highly relevant for the operational safety of passenger cars and commercial vehicles – so, these parts must not fail even at harsh usage and minimum maintenance. The most cost & time efficient approach for the durability performance approval is an accelerated life test using service load simulation. Therefore, a laboratory based environment for the whole assembly and realistic load interaction provides unrivalled results for durability and operational safety.

The biaxial wheel fatigue test technology (ZWARP) is successfully used since the early 1980’s and today a worldwide standard for laboratory service load simulation. Both, test rig hardware and load files have been invented and developed by Fraunhofer LBF – a leading R&D institute for durability & fatigue research. Today the complete technology is used at many OEM – such as Porsche, BMW, Daimler, Volkswagen, Ferrari, Maserati, Volvo Car, MAN, Volvo Truck, Daimler Truck – and leading wheel manufacturing companies too.

R&D Services of LBF Team

Fraunhofer LBF is providing the most complete service for R&D and contract testing and has the largest number of test facilities for laboratory testing. Spectrum based service load simulation is effectively performed using accelerated load files which are developed by Fraunhofer LBF for any biaxial test rig hardware. Hereby the complete service life of 12 to 18 years is performed within a few days only, considering the confidence of an economic number of test objects statistically.

Beside standard test specifications according to LBF or OEM standards, Fraunhofer LBF supports its customers to apply the most efficient test strategy for individual needs & wants. Therefore, highly sophisticated procedures are available which include biaxial flat track measurements, strain gauge applications, flange pre-damage caused by curbs, or computational fatigue analysis using tire models and damage accumulation.  

Since more than thirty years the whole ZWARP technology comes from Fraunhofer LBF and is applied to customers in all major countries – including test rig & load file customization, comprehensive users training, as well as complete technology integration projects for a seamless operation at the customers site.

How to cooperate with LBF?

Using the knowhow and test rig hardware from Fraunhofer LBF is an easy & efficient task: Simply shipping the wheels to LBF in Darmstadt, Germany, including the information about:

  • target vehicle range
  • operational conditions
  • OEM specific standards
  • wheel size
  • wheel load
  • tire type & size

By having those information available, Fraunhofer LBF is able to conduct a quotation for contract testing including the information about timing and processing.

Furthermore any requirement related to wheel & hub durability performance evaluation can be discussed with the experts from Fraunhofer LBF, as well as customer specific solutions can be offered to provide excellence in wheel design, analysis and testing.