An investigation of the impact behavior of a rigid body

Abstract

Modern freeways require adequate lighting facilities, and in order to meet lighting requirements, light posts sometimes have to be located near the edge of the traffic lane. Single post sign standards and stop light posts are also necessary. Each of these post installations is often located so as to constitute a safety hazard and collision with these posts can cause fatalities. The Texas Transportation Institute at Texas A & M University has been investigating the methods of developing supports that will limit impact forces to tolerable limits and a design showing considerable merit is the "break-away" post that disengages the post from its foundation upon impact. Normally posts are quite massive and after impact they could be knocked into the path of the vehicle, or onto the highway, causing an unsafe condition for other motorists. In this research, the work was directed toward developing a post system that, upon impact, would be knocked out of the vehicular path and caused not to land on the highway causing hazardous circumstances. The post model was assumed to be a rigid body under the action of constant and time dependent forces while the vehicle was taken as a spring-mass system with a single degree of freedom. ...