Characterization and analysis of chain-link fences

A program was initiated to characterize a chain-link fence using a time-dependent three-dimensional vibration analysis in order to provide a better understanding of the effects of the physical characteristics as well as the motion of the fence structure. The primary goals of the analysis were to develop a series of test procedures which would duplicate cutting and climbing attempts, and to develop a clear understanding of the fence construction requirements in order to reduce the nuisance alarm rates due to the varying environmental conditions. The theoretical and experimental analysis took account of wind velocity and other environmental noise, as well as the fence construction. A discussion is presented of the theoretical analysis and the experimental results of the program. Commercial fence sensors were compared to sensitive accelerometers. The results indicate that the commercial sensors are most sensitive at low frequencies. They could not be used to detect some of the high-frequency events which might be useful for distinguishing intrusion attempts from nuisance alarms