Various vibration isolators using negative stiffness elements have been proposed in order to improve ride comfort of passengers in vehicles. In this paper, five different ones are compared. Four of them have been already propped, while the fifth one is novel, based on the KDamping concept, which has proven efficient in other applications. After optimising each one with respect to static and dynamic factors of ride comfort, three types of analysis are performed. In the first type, the models are simulated for the optimum solutions, for two more excitations which correspond to the response of the vehicle's body while driving over road profiles of Class B and C. In the second type, the models are simulated for different seated passengers. While in the third type, based on the Pareto theory, three solutions are finally selected for each model, and their transmissibility from seat to head (STHT) is compared. The main conclusion is that the isolator using the KDamping concept has proven its adaptability and universality for different excitations corresponding to different road classes and for different seated passengers, minimising the resonance frequency around 0.56 Hz and providing the most compact and comfortable optimum design solutions among all the other models.

A seat that provides good vibration isolation is of prime importance for passenger’s safety and health. The main conflict in seat suspensions implies that the increasing initial deformation of the system (increase in “static discomfort”) leads to better isolation of accelerations (increase in “dynamic comfort”). Many researchers have focused on overcoming or at least suppressing this conflict between load support capacity and vibration isolation by modeling new suspension systems, such as the so-called negative suspension systems. However, apart from the modeling of new suspension systems, optimization is an important part in designing a seat and finding the best compromise between these two objectives. Thus, in this work, four types of seat suspension systems with embedded negative stiffness elements are implemented and optimized in order to be benchmarked. Three of them have already been tested either in passenger or in an off-road vehicle seat. All the vibration isolators are optimized with genetic algorithms in respect to static and dynamic factors of ride comfort by applying constraints oriented to the objectives and the design of the structure. The optimization is implemented for two excitations, which correspond to a vehicle driving over road profiles of Classes A and B, and the common solutions are outlined.