Global Defence Solutions (Nowra, New South Wales, Australia)
Global Defence Solutions (GDS) required structural assessment and design verification of the ITT-C air transportable container for the Australian Defence Force. Structural analysis of the ITT-C container frame, roof and wall/floor panels was required to be performed in accordance with strength and fatigue requirements of various container codes, standard MIL-STD-810H and standards AS 4100 and AS/NZS 1170.0 considering applied permanent and imposed (vibration, shock) loads combined with equivalent non-structural mass representations of cargo items (i.e. driver module, turret module, aircon, electronics rack, desk/monitor frame).
What we did:
- Performed strength analysis (structural FEA) of ITT-C container applying MIL-STD-810H code specified truck, aircraft and ship induced shock/vibration loads
- Performed time and frequency domain fatigue assessment of ITT-C container considering MIL-STD-810H code specified aircraft and ship shock/vibration loads (applying the Dirlik solution method to determine stress range probability density functions from PSD frequency data)
- Applied uniform material law (UML) specified fatigue strength values to calculate time based equivalent fatigue damage (applying FEA fatigue assessment practices from standard BS 7608) and Palmgren-Miner rule for fatigue damage accumulation
- Compared fatigue analysis results with specified operating hours for ITT-C container service life determination.
- Issued certificate of compliance indicating design compliance of the ITT-C container in accordance with Cont-029b and relevant Australian standards for strength and serviceability.
Outcome:
Avesta Consulting verified compliance of the design with the engineering principles and intent of standard AS 4100 for strength and best engineering practices for fatigue considering permanent, lifting and imposed (vibration, shock) loads derived from standard AS/NZS 1170.0, measured PSD vibration data and MIL-STD-810H code specified truck, aircraft and ship shock/vibration loads.
