Investigation of Vehicle Shock Absorbers for Low-Cost Seismic Protection of Structures

This paper describes a study to determine the suitability of vehicle shock absorbers for use as seismic protection devices. Studies of various types of supplemental damping devices have shown that there are particular benefits to using viscous fluid dampers (VFD’s) for seismic protection. Vehicle shock absorbers have similar mechanical properties to VFD’s that, in theory, make them a viable alternative. In addition, the low cost of vehicle shock absorbers makes them attractive for use in lower budget projects. Using models of vehicle shock absorbers that are available in the literature, a comparison is made between the behavior of shock absorbers and VFD’s when they are subjected to harmonic motion. The comparisons indicate that vehicle shock absorbers can be configured to provide response characteristics that are similar to VFD’s, thereby suggesting their potential application for seismic protection of structures. The overall goal of the research presented herein is to identify vibration control devices that could be used for low-cost seismic protection. To accomplish this goal, a suboptimal design objective is proposed wherein the protection system provides sufficient protection, although not optimal, while incurring low cost. The suboptimal design process begins with identifying suitable vibration control devices that are readily available (off-the-shelf units that are mass-produced with associated cost reduction). This paper describes this first step in the suboptimal design process.