Shape optimization of helicopter subfloor intersection element under crash loading

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Makina Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2017

Öğrenci: MUSTAFA OKAN TÜRE

Danışman: SERKAN DAĞ

Özet:

The aim of the crashworthiness is maintaining a survivable space for occupants and absorb crash energy as much as possible. The statistics showed that 85% of all rotorcraft accidents can be survivable. Thus, crashworthy design has direct effect on occupants' survival. This thesis analyses a longitudinal beam and lateral frame intersection point on helicopter subloor. Analysis is performed on ABAQUS Dynamic/Explicit solver. Analysis includes high deformation levels, self-contact and nonlinearities. 110 kg mass is dropped on test structure to simulate crush. The test specimen impacted at 7 m/s vertical speed. To improve the design concept, energy absorption capability of the structure will be examine. Test verification is performed in the first part. After modelling techniques set with verification, geometric optimization is performed to get better energy absorbing capability of subfloor structure. Genetic algorithm is used while finding the best crashworthy solution in our design limits. At the first part of optimization, only geometric variables are investigated. At the second part, material is added as another parameter. Optimum energy absorber structure is aimed as a result of this process.