The Structural Dynamics Group of Sinclair Knight Merz was commissioned to provide independent advice on the reliability of an upgraded drive train system for the M113A1.
Independent industry wide survey to determine drivetrain reliability
A review of the drivetrain reliability (Mean Time Between Failures MTBF) was undertaken by benchmarking the uprated M113 MTBF with data for the existing drivetrains and other defence and off-road equipment. A survey of MTBF’s for engines, transmissions and final drives was undertaken using SKM’s client database in the Mining and Forestry Industries. Tracked and rubber tyred machines were included in the survey.
Advanced solid modelling enables casing strength improvements to be evaluated
A mechanical and structural design audit was also undertaken for the critical final drive unit. All gears, shafts and bearings were checked for strength and fatigue durability. Finite models of the current and uprated final drive casings were constructed and assessed for peak and fatigue loads The uprated gearcase was modified to provide enhanced durability characteristics and thereby ensure that the MTBF was not limited by structural performance. The design review provided our client with confidence that substantial improvements in reliability could be achieved with the proposed new design.
