A study of gelatin bird strike pressure profiles and the importance of deviatoric stresses for bird strike simulations
| dc.contributor.advisor | Simoneau, Andy | |
| dc.contributor.author | Kennedy, Shaun | |
| dc.date.accessioned | 2025-09-11T17:00:35Z | |
| dc.date.available | 2025-09-11T17:00:35Z | |
| dc.date.issued | 2025-06 | |
| dc.description.abstract | Computer simulations are typically used in the design of aircraft to ensure safety in the event of a bird strike. However, there is very little published experimental data available for validating potential bird impact models. To address this void, 17 impact tests were performed. The peak pressures achieved in this work were significantly higher than previously published results. Parametric studies were carried out to determine the effects of bird model parameters on the resulting impact pressure profile. While previous works have claimed to successfully match experimental pressure profiles, the experimental and modeling results from this research highlight the very limited success of previous experimental and modeling results, and their interpretation. The parametric studies carried out enabled the development of a material model that more closely matches the more reliable experimental results carried out in this research. One of the most important results from this research is the conclusive evidence towards the importance of peak impulse. In the past, it was assumed by some that the peak portion of the pressure profile is negligible as compared to the steady-state portion and may be ignored. However, the results from this research clearly demonstrated the significance of the peak impulse as it was shown that the peak deflection of an aluminum plate was increased with increasing peak impulse even when the steady-state and total impulses were decreased. The importance of shear thickening behavior and deviatoric stresses was discovered in the research. While it has been shown that the dynamic viscosity of gelatin increases exponentially with strain rate, this research demonstrates how the shear thickening behavior of the gelatin bird could cause the dynamic viscosity to increase significantly during the high strain rate impact event. This increase in dynamic viscosity was shown to have a significant effect on the pressure profiles created during the event and demonstrated the importance of considering the deviatoric terms of a material model as opposed to just considering the hydrodynamic terms as was done in the past by many researchers. A suggested shear thickening bird material model was also proposed for future work. | |
| dc.description.copyright | ©Shaun Kennedy, 2025 | |
| dc.format.extent | xviii, 191 | |
| dc.format.medium | electronic | |
| dc.identifier.uri | https://unbscholar.lib.unb.ca/handle/1882/38387 | |
| dc.language.iso | en | |
| dc.publisher | University of New Brunswick | |
| dc.rights | http://purl.org/coar/access_right/c_abf2 | |
| dc.subject.discipline | Mechanical Engineering | |
| dc.title | A study of gelatin bird strike pressure profiles and the importance of deviatoric stresses for bird strike simulations | |
| dc.type | doctoral thesis | |
| oaire.license.condition | other | |
| thesis.degree.discipline | Mechanical Engineering | |
| thesis.degree.grantor | University of New Brunswick | |
| thesis.degree.level | doctorate | |
| thesis.degree.name | Ph.D. |