An Improved Biomechanical Model to Optimize Biodynamic Responses Under Vibrating Medium

Abstract

The vibration is a mechanical phenomenon created by man or machine. Persons involved in on/off-road vehicle driving expose to intense vibrations and shocks owing to uneven and asymmetrical terrains. The prolonged vibration exposure may lead to musculoskeletal disorders followed by injuries. To examine human body movements and biodynamic responses precisely, it is obligatory to establish a reliable biomechanical model. To do so, the present paper proposes a ten degrees-of-freedom (dofs) biomechanical model of the seated human. The novelty of the proposed model is that it hypothetically divides the real human structure into segments as a head, thorax, abdomen, pelvis, left upper arm, left forearm, left hand, right upper arm, right forearm, and right hand, respectively, which are mainly missing in the human model developed in past. The mechanical parameters are utilized to define the biomechanical model and optimized through the firefly algorithm. After optimization, the biodynamic responses: seat to head transmissibility, apparent mass and driving point mechanical impedance are calculated for the proposed model and compared with Allen2-dofs model, Wan and Schimmels4-dofs model, Bai et al.4-dofs model, Darling et al.7-dofs model and Boileau et al.experimental. The overall goodness of fit is compared for the proposed model with five other models and found that the proposed model gives maximum goodness of fit (93.47). Also, the sensitivity analysis (± 10% variation in mass, stiffness and damping) is performed to validate the reliability of the developed model. And, it is observed that the mass, stiffness, and damping of the pelvis region have a significant role in peak modulus of biodynamic responses.