Modal analysis for evaluating the transmission of vertical vibrations in a wheelchair-occupant model with foam-based seat cushion

. An 11-degrees-of-freedom (11-DOF) model is constructed to evaluate the transmission of vertical vibrations in wheelchair-occupant systems. Modal analysis is employed to develop reliable dynamic models that predict the steady-state response accurately. The modal analytical method demonstrates high accuracy by successfully predicting seat transmissibility and comparing favorably with published results. Analysis identifies the occupant's torso as having the highest amplitude ratio of transmissibility responses, facilitating the identification of vibration phenomena. A linear differential equation model with 11 degrees of freedom effectively predicts the behavior of foam-based cushions in vibration and shock absorption. Comparisons with experimental data validate the model's performance. This modeling approach has significant potential for advancing wheelchair design and analyzing vibrating systems. Future research can further enhance the model by incorporating complex geometries and material properties, coupled with experimental validation. Addressing limitations and pursuing suggested directions will improve accuracy, reliability, and applicability, contributing to a deeper understanding of vibration transmissibility and prioritizing occupant comfort and safety in wheelchair systems.