EFFECTS OF THE SEAT CUSHION OSCILLATORY PARAMETERS ON VIBRATION  EXPOSURE AND DYNAMIC SEAT COMFORT IN THE BUS

Dragan Sekulić; Ivan Ivković; Dušan Mladenović

doi:10.5937/jaes15-14604

Dragan Sekulić Univerzitet u Beogradu, Saobracajni fakultet
Ivan Ivković Univerzitet u Beogradu, Saobracajni fakultet
Dušan Mladenović Univerzitet u Beogradu, Saobracajni fakultet

DOI: https://doi.org/10.5937/jaes15-14604

Keywords: ride comfort, dynamic seat comfort, oscillatory models, standard ISO 2631, Matlab/Simulink, ADAMS/View,

Abstract

The paper analyzed the influence of the passenger seat’s cushion oscillatory parameters (stiffness/damping) on ride comfort and dynamic seat comfort. The analysis was done using a linear in-line oscillatory seat-human model with 4 degrees of freedom (DOF) defined in Matlab/Simulink. For the oscillatory excitations of the in-line model, the vertical accelerations of the bus floor under the users’ seats were used. Bus floor accelerations were obtained by simulation using validated spatial oscillatory intercity bus model with 65 DOF defined in the ADAMS/View software. The ride comfort was assessed by the criteria of ISO 2631/1997 standard. The seat effective amplitude transmissibility (SEAT_rms) parameter was considered for analyzing the dynamic seat comfort. It was found that passengers in the rear part of the bus had a lower level of ride comfort than the passengers in the front part of the bus. The intensities of the bus floor vertical accelerations for the rear part were mainly concentrated in the frequency range of 5-10 Hz. Passengers at the rear had lower SEAT_rms values than those at the front. The SEAT_rms values increased noticeably with the increase in the cushion stiffness, but those values were below 100% for all considered users. Increase in the cushion damping slightly decreased SEAT_rms values.

References

Ahmadian, M., Seigler, M.T., Cllapper, D., Sprouse, A. (2002) A Comparative Analysis of Air-inflated and Foam Seat Cushions for Truck Seats, SAE International, pp. 11.

Allen, G.R. (1979) A Critical Look at Biodynamic Modeling in Relation to Specifications for Human Tolerance of Vibration and Shock, part 2. In: AGARD-CP-253, paper A 25, pp. 519.

Boileau, P., Rakheja, S. (1998) Whole-body vertical biodynamic response characteristics of the seated body biodynamic response under vertical vibration. Journal of Sound and Vibration, 215 (4), pp. 841–62.

Diligenski, Dj., Demić, M., Šakota, Ž. (2005) Bus passenger vibrational comfort. MVM Monograph, Faculty of Mechanical Engineering, Kragujevac.

Ebe, K., Griffin, M.J. (2000) Qualitative models of seat discomfort including static and dynamic factors. Ergonomics, 43 (6), pp. 771-790.

Fairley, T.E., Griffin, M.J. (1989) The Apparent Mass of the Seated Hurnan Body: Vertical Vibration. Journal of Biomechanics, 22 (2), pp. 81-94.

Griffin, M.J. (1978) The evaluation of vehicle vibration and seats. Applied Ergonomics, 9 (1), pp. 15-21.

International Organisation for Standardization Cornmittee Draft CD 5982. (1993) Mechanical Driving Point Impedance and Transmissibility of the Human Body, Document ISOmC 108/SC 4N226. pp. 21.

International Organisation for Standardization. (1997) Guide for the evaluation of human exposure to whole body vibration, ISO 2631. pp. 31.

Mahesh, P.N., Gahininath, J.V.P., Rahul, N.Z.P. (2016) Optimization of nonlinear quarter car suspension–seat–driver model. Journal of Advanced Research, 7 (6), pp. 991–1007.

Mansfield, N.J. (2006) Literature Review On Low Frequency Vibration Comfort. Loughborough University, Loughborough, U.K., pp. 104.

Mertens, H. (1978) Nonlinear Behavior of Sitting Humans Under Increasing Gravity. Aviation, Space and Environmental Medicine, 49 (1), pp. 287-298.

Nahvi, H., Fouladi, M.H., Nor, M.J.M. (2009) Evaluation of whole-body vibration and ride comfort in a passenger car. International Journal of Acoustics and Vibration, 14 (3), pp. 143-149.

RoadRuf Software. (1997) Software for analyzing road profiles. The University of Michigan Transportation Research Institute.

Sekulić, D. (2013) Investigation of Passengers' Oscillatory Comfort in the Bus with Respect to the Seat Position and Quality (Ph.D. thesis) (in Serbian). University of Belgrade, The Faculty of Transport and Traffic Engineering, Belgrade.

Sekulić, D., Dedović, V., Rusov, S., Obradović, A., Šalinić, S. (2016) Definition and determination of the bus oscillatory comfort zones. International Journal of Industrial Ergonomics, 53, pp. 328-339.

Suggs, C.W., Stikeleather, L.F., Harrison, J.Y., Young, R.E. (1970) Application of a Dynamic Simulator in Seat Testing. Transaction ASAE, 13 (3), pp. 378-381.

Tchermychouk, V. (1999) Objective assessment of static and dynamic seats under vehicular vibration. Master Thesis, Concordia University, Montreal, Quebec, Canada, pp. 180.

Ahmadian, M., Seigler, M.T., Cllapper, D., Sprouse, A. (2002) A Comparative Analysis of Air-inflated and Foam Seat Cushions for Truck Seats, SAE International, pp. 11. Allen, G.R. (1979) A Critical Look at Biodynamic Modeling in Relation to Specifications for Human Tolerance of Vibration and Shock, part 2. In: AGARD-CP-253, paper A 25, pp. 519. Boileau, P., Rakheja, S. (1998) Whole-body vertical biodynamic response characteristics of the seated body biodynamic response under vertical vibration. Journal of Sound and Vibration, 215 (4), pp. 841–62. Diligenski, Dj., Demić, M., Šakota, Ž. (2005) Bus passenger vibrational comfort. MVM Monograph, Faculty of Mechanical Engineering, Kragujevac. Ebe, K., Griffin, M.J. (2000) Qualitative models of seat discomfort including static and dynamic factors. Ergonomics, 43 (6), pp. 771-790. Fairley, T.E., Griffin, M.J. (1989) The Apparent Mass of the Seated Hurnan Body: Vertical Vibration. Journal of Biomechanics, 22 (2), pp. 81-94. Griffin, M.J. (1978) The evaluation of vehicle vibration and seats. Applied Ergonomics, 9 (1), pp. 15-21. International Organisation for Standardization Cornmittee Draft CD 5982. (1993) Mechanical Driving Point Impedance and Transmissibility of the Human Body, Document ISOmC 108/SC 4N226. pp. 21. International Organisation for Standardization. (1997) Guide for the evaluation of human exposure to whole body vibration, ISO 2631. pp. 31. Mahesh, P.N., Gahininath, J.V.P., Rahul, N.Z.P. (2016) Optimization of nonlinear quarter car suspension–seat–driver model. Journal of Advanced Research, 7 (6), pp. 991–1007. Mansfield, N.J. (2006) Literature Review On Low Frequency Vibration Comfort. Loughborough University, Loughborough, U.K., pp. 104. Mertens, H. (1978) Nonlinear Behavior of Sitting Humans Under Increasing Gravity. Aviation, Space and Environmental Medicine, 49 (1), pp. 287-298. Nahvi, H., Fouladi, M.H., Nor, M.J.M. (2009) Evaluation of whole-body vibration and ride comfort in a passenger car. International Journal of Acoustics and Vibration, 14 (3), pp. 143-149. RoadRuf Software. (1997) Software for analyzing road profiles. The University of Michigan Transportation Research Institute. Sekulić, D. (2013) Investigation of Passengers' Oscillatory Comfort in the Bus with Respect to the Seat Position and Quality (Ph.D. thesis) (in Serbian). University of Belgrade, The Faculty of Transport and Traffic Engineering, Belgrade. Sekulić, D., Dedović, V., Rusov, S., Obradović, A., Šalinić, S. (2016) Definition and determination of the bus oscillatory comfort zones. International Journal of Industrial Ergonomics, 53, pp. 328-339. Suggs, C.W., Stikeleather, L.F., Harrison, J.Y., Young, R.E. (1970) Application of a Dynamic Simulator in Seat Testing. Transaction ASAE, 13 (3), pp. 378-381. Tchermychouk, V. (1999) Objective assessment of static and dynamic seats under vehicular vibration. Master Thesis, Concordia University, Montreal, Quebec, Canada, pp. 180.