Global Defence Solutions (Nowra, New South Wales, Australia)
Global Defence Solutions required structural assessment and design verification of the EASI HR SW deployable container for the Australian Defence Force. Structural analysis and mechanical assessment of the EASI HR SW container steel frame, container walls/floors, composite roof, canvas walls, winches/cables, doors (including hinges/door mechanisms), ducting, lining and levelling posts/gas struts was required to certify the container assembly in accordance with the strength and serviceability requirements of codes DEF(AUST) 9009A, MIL-STD-810H and relevant Australian standards (i.e. AS 4100, AS/NZS 1170.0, AS/NZS 1170.2) considering applied dead, live, acceleration (shock, vibration) and wind loads for aircraft, truck and ship transportation.
What we did:
- Performed strength assessment (structural FEA) of EASI HR SW container structural components considering applied dead, live, acceleration (shock, vibration), wind and lifting loads to confirm design compliance with standard AS 4100 strength and serviceability requirements.
- Performed time and frequency domain fatigue analysis of EASI HR SW container structural components considering aircraft, truck and ship shock/vibration loads (applying the Dirlik solution method to determine stress range probability density functions from PSD frequency data) with application of uniform material law (UML) specified fatigue strength values to calculate time based equivalent fatigue damage, Palmgren-Miner rule based fatigue damage accumulation, and GDS specified operating hours for EASI container service life determination.
- Performed assessment of mechanical components based on OEM specifications and engineering calculations.
Outcome:
Avesta Consulting verified the structural integrity and fatigue life of the EASI HR SW container and developed appropriate design modifications to achieve minimum fatigue life requirements.
