| Description |
The purpose of this research is to verify the structural integrity of the AN/FPS-117 Long Range Radar and radar tower. An investigation is performed to understand how the fluctuating loads have an impact on the nucleation of crack-like discontinuities and the service life of the components and what steps should be taken as a result of the analysis. It is hypothesized that the rotation of the radar, in conjunction with the variation in level of the platform, creates fluctuating loads in support members that will decrease the life and reliability of these and other radar components. An analysis is conducted of the changes in stress and strain amplitudes on the structure due to the rotation of the radar. Based on the material type, fatigue properties were determined and a strain-life curve was constructed to approximate the number of cycles to failure. The resulting strain amplitude from the fluctuation of loads was found to be relatively small compared to the strain-life curve. The change in radar level did not have a significant impact on the strain amplitude and calculated cycles to failure based on strain gage measurements. A damage tolerance assessment was completed to estimate the crack growth rate of the cracks found in the radar support plate. The results from this analysis were compared with a failure analysis that was performed on the radar support plate. |
