Structural testing of a 200 tonne mobile structure

The Australian Defence Force operates a non-flying mock-up wide bodied aircraft, similar in appearance to a short-bodied Boeing 747. After a short period of use, the mock-up suffered a major structural failure of the rear undercarriage assemblies. Extensive testing was conducted to determine tyre stiffness parameters required to redesign the supporting structure. Following the completion of extensive modifications, strain gauges were placed on large box sections, and forces transmitted from the bogies to the superstructure were measured during a series of trials. In this paper, the strain gauging system is described, and the method for obtaining forces, moments and torques is discussed. Typical results obtained during towing around curved paths are presented.