Investigation of Seat Suspensions with Embedded Negative Stiffness Elements for Isolating Bus Users’ Whole-Body Vibrations

Abstract

Buses drivers are group at risk who often suffer from musculoskeletal problems, such as low-back pain, while bus passengers on the last row seats are experiencing accelerations of high-values. In this paper, the contribution of K-seat in decreasing the above is investigated with a detailed simulation study. The K-seat model, a seat with a suspension that functions according to the KDamper concept, which combines a negative stiffness element with passive one, is bench-marked against the conventional passive seat (PS) in terms of comfort when applied to different bus user's seats. More specifically, it is tested in the driver's and two different passenger's seats, one from the rear overhang and one from the middle part. For the benchmark's shake, both are optimized by applying excitations which correspond to real intercity bus floor responses when it drives over a real road profile. Then, a human model is placed to the seats in order to compare their optimum solutions in terms of user's whole-body vibrations, using objective comfort metrics. Based on the results, the K-Seat improves significantly the comfort of the users (~92%) compared to the PS, while it achieves similar decrease in the maximum values of the user's back accelerations (~97%).