Fatigue Analysis at G Forces
The frame had several masses attached to it to facilitate machine operation. The frame moved through space at rapid speeds, generating acceleration, which was in multiples of gravity. (Typically 1.5 times)
Not only the magnitude of the G force changed, but also its direction as the frame had to traverse in Horizontal and Inclined planes at high velocities. This change in direction created a Fatigue cycle.
Initially all possible load directions were worked out and analysis was done at those conditions. The stress patterns were studied to identify location of high stresses and locations where stresses changed direction (i.e. From tensile to compressive)
Such location were termed as risk points under fatigue, and Means stresses were calculated for these locations and using SN curve life was estimated.
The model was further optimized to increase life, as per client requirements.
Fatigue Analysis using Mean Stress Calculation
