Development of a detailed aircraft tyre finite element model for safety assessment

Abstract This paper describes the development of a detailed finite element (FE) model of an aircraft test tyre in order to investigate its performance and assess its safety criteria. It is noticed that rubber and fabric composite materials are the major components of this tyre model and their characterization requires tests and correlation. The characterization of such materials is of great importance in the model development process. Due to its complicated mechanical behaviour that exceeds the linear elastic theory, rubber is generally considered as hyperelastic material in FE analysis. It can be defined by a stored energy function with various coefficients that need to be determined by a series of experimental test data. The key issue is to define an appropriate energy function that can provide good fit with the experimental test data. Initially, a full-scaled LS-Dyna FE model has been development to replicate the actual geometry of the target test tyre. The material properties of each individual component have been characterized and correlated with industrial uniaxial tension test data. The inflation and static load simulations have been analyzed basing on the characterized tyre model, indicating its reliability. The dynamic simulations that aim to duplicate tyre load upon aircraft landing scenarios have also been analyzed. Following the comments and guidelines from aircraft industrial data, the dynamic simulations have covered the tyre loading scenarios from normal (soft) landing, hard landing to crash landing under different aircraft landing weights and vertical speeds. The tyre deflection rate and the contact load have been chosen as the safety criteria. The simulation analysis, results and comments have been discussed in detail. The modelling and correlation processes described in this paper aim to demonstrate the importance of hyperelastic material characterization in developing a detailed FE tyre model. Such a predictive model can be effectively used during tyre design process to allow manufacturers to assess its availability, and also add to the general drive towards the use of more virtual prototypes in an area traditionally reliant on experimental testing.