Impact tests of wheels of road vehicles: A comprehensive method for numerical simulation

In the design of automotive wheels, safety is a crucial factor. Homologations, legislation and standards require severe impact tests before a new wheel can be released on the market. Impact tests are usually performed after the wheel has been already designed and the first prototypes have been produced. In case of test failure, significant delays and costs have to be sustained before the wheel can be actually produced. Numerical simulation of wheel impact tests can reduce the risk of test failure and be a valuable tool for the designer to obtain more efficient and light wheels.The paper deals with the full digitalization of the design process of road vehicle wheels. The aim is to reduce as much as possible indoor impact tests to assess wheel rim structural safety. The numerical simulation of impact tests is accomplished by complex finite element models comprising wheel, tyre and test rig structure. Several data can be required for the modelling of the tyre, which are not usually known to the wheel designer. In this paper, a method for the realization of finite element models of different impact tests is presented. By the proposed method, finite element models with a sufficient level of accuracy for the design of the wheel, at a relatively low computational cost, can be obtained by means of a well defined procedure. For tyre characterisation, only simple measurements related to geometrical features, stiffness and frequency response are required. The method is successfully applied to different impact tests such as radial impact tests with flat or V-shaped striker and 13∘ side impact test. For all the considered tests, experimental validations are performed on different wheels, instrumented with strain gauges located at the most stressed areas. The striker accelerations are also reproduced accurately. The method for the numerical simulation of indoor impact tests of road vehicle wheels enables the full digitalisation of design process, with relevant results in terms of ”time to market” reduction and structural safety assessment. The proposed method is useful not only to design wheel rims, but also to design pneumatic tyres.