AbstractThe use of composite crash structures in Formula One (F1) has been the subject of extensive research and investment over the past few decades, with the aim of increasing driver safety. However, these structures are quite costly to produce, and they need to be experimentally certified before being used. As design engineers seek ways to reduce the mass of such structures, it becomes increasingly challenging to ensure a high level of crashworthiness. The commercial design tools currently available to F1 teams have not yet been properly assessed in terms of their ability to predict composite crushing in a reliable and cost-effective manner. There is also a general lack of publicly available experimental and numerical data which could be used by researchers to assess and further develop the current numerical tools.
This thesis presents an experimental and numerical study on the crashworthiness of F1 composite crash structures. The experimental data produced during this thesis is very valuable, since it provides for the first time all the information and results obtained from crash testing a real F1 Side Impact Structure (SIS). This kind of experimental data, which is usually kept confidential, can serve as a benchmark with which to assess the numerical tools. The quasi-static and dynamic crush tests of the SIS were also complemented with similar crush tests of small flat and tubular coupons of various layups.
This thesis also presents some preliminary experimental studies which were performed in order to develop novel and reliable characterisation methods for the intralaminar fracture toughness properties of the composite materials being used. These properties are essential input parameters for most of the numerical tools used to assess crashworthiness, since they define the amount of energy being dissipated by the material during crushing.
Using the material properties obtained from these quasi-static characterisation tests, meso-scale (ply-level) simulations were performed, using an in-house intralaminar damage model, to predict the crushing response of the small coupons. The results show the need for further experimental characterisation and numerical Abstract viii developments, before this modelling approach can become a reliable predictive tool for virtual coupon testing.
The SIS was also modelled numerically, using both the meso-scale approach of the small coupons, and the macro-scale (laminate-level) approach currently being assessed by F1 teams. Results show that the macro-scale simulations are clearly less computationally expensive and can provide comparable quantitative responses to those observed experimentally, both quasi-statically and dynamically. However, the experimental coupon tests, from which the macro-scale simulation material crushing parameters were obtained, need to be further investigated. The meso-scale results, similar to what was observed from the coupon simulations, show the need of further experimental and numerical developments.
|Date of Award||Jul 2020|
|Sponsors||Northern Ireland Department for the Economy|
|Supervisor||Brian Falzon (Supervisor) & Giuseppe Catalanotti (Supervisor)|