This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
System Identification of Quasi-static Foam Behavior and its Application in H-point Prediction
Technical Paper
2003-01-2207
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
Hip joint location (H-point) is an important design specification used by car seat manufacturers. Since most of the modern car seats are full-foam seats, the H-point location is primarily dependent on the quasi-static behavior of foam which is a highly nonlinear and viscoelastic material. In this work, a constitutive model is developed for flexible polyurethane foam. The stiffness characteristics of foam are described by a polynomial in displacement and the viscoelastic behavior is described by a convolution of the response with a kernel which is assumed to be a sum of exponentials. A system identification procedure, based on linear least squares fitting and ARMA modeling, is developed to identify the parameters from data collected in quasi-static foam experiments. Once identified, these models of foam are incorporated into two dimensional multi-degree-of-freedom seat occupant models to determine the static equilibrium position of an occupant in a seat from which the H-point location is determined. A graphical user interface is developed to facilitate study of the influence of changes in system parameters and also to visualize the settling of the occupant in the seat.
Authors
Topic
Citation
Ippili, R., Davies, P., and Bajaj, A., "System Identification of Quasi-static Foam Behavior and its Application in H-point Prediction," SAE Technical Paper 2003-01-2207, 2003, https://doi.org/10.4271/2003-01-2207.Also In
References
- Griffin M. J. 1990 Handbook of Human Vibration Academic Press
- Pope M. H. Pope D. G. Jorneus L. Broman H. Svensson M. Andersson G. 1987 The Response of the Seated Human to Sinusoidal Vibration and Impact Journal of Biomechanical Engineering 109 279 284
- Lee J. Paul P. Temming J. 1993 Measuring Seat Comfort Automotive Engineering 101 July 1993 25 30
- Wu X. Rakheja S. Boileau P.-E. 1998 Study of Human-Seat Interface Pressure Distribution Under Vertical Vibration International Journal of Industrial Ergonomics 21 433 449
- Yu L. C. Khameneh K. N. 1998 Automotive Seating Foam: Subjective Dynamic comfort Study Polyurethanes Expo '98 Proceedings 485 589 September 17-20 1998 Dallas, TX
- Isobe M. Hiraide T. Utsumi H. Ohkubo K. Sakai S. 1998 An Approach to Evaluation of Riding and Seating Comfort Polyurethanes Expo '98 Proceedings 507 515 September 17-20 1998 Dallas, TX
- Inagaki H. Taguchi T. Yasuda E. Iizuka Y. 2000 Evaluation of Riding Comfort: From the Viewpoint of Interaction of Human Body and Seat for Static, Dynamic, Long Time Driving SAE 2000-01-0643
- Ebe K. Griffin M. J. 2001 Factors Affecting Static Seat Cushion Comfort Ergonomics 44 901 921
- Ebe K. Griffin M. J. 2000 Qualitative Models of Seat Discomfort Including Static and Dynamic Factors Ergonomics 43 771 790
- Lakes R. S. Lowe A. 2000 Negative Poisson's Ratio Foam as Seat Cushion Material Cellular Polymers 19 157 167
- Crocco G. L. Roeck H. De. Balancing the Static and Dynamic Comfort Properties of Polyurethane Foam for Automotive Seating Polyurethanes Expo '98 Proceedings 463 470 September 17-20 1998 Dallas, TX
- Van Heumen J. D. Blair G. R. 1998 Polyurethane Seating Comfort: Analysis of Foam Formulation Contribution Polyurethanes Expo '98 Proceedings 491 506 September 17-20 1998 Dallas, TX
- Gronen J. Schmidt M. Raffel B. Wagner J. Koshute M. A. Haider K. 1997 New TDI-based isocyanates: Advances in Flexible Molded Foams for Automotive Seating Polyurethanes World Congress 1997 394 401 September 29 October 1 1997 Amsterdam
- Casati F. M. Herrington R. M. Broos R. Miyazaki Y. 1997 Tailoring the Performance of Molded Flexible Polyurethane Foams for Car Seats Polyurethanes World Congress 1997 402 421 September 29 October 1 1997 Amsterdam
- Fairley T. E. Griffin M. J. 1989 The Apparent Mass of the Seated Human Body: Vertical Vibration Journal of Biomechanics 22 2 81 94
- Muksian R. Nash C. D. 1974 A Model for the Response of Seated Humans to Sinusoidal Displacements of the Seat Journal of Biomechanics 7 209 215
- Patil M. K. Palanichamy M. S. 1988 A Mathematical Model of a Tractor-Occupant System with a New Seat Suspension for Minimization of Vibration Response Applied Mathematical Modelling 12 63 71
- Wan Y. Schimmels J. M. 1997 Optimal Seat Suspension Design Based on Minimum Simulated Subjective Response Journal of Biomechanical Engineering 119 409 416
- Patten W. N. Pang J. 1998 Validation of a Nonlinear Automotive Seat Cushion Vibration Model Vehicle System Dynamics 30 55 68
- Fairley T. E. Griffin M. J. 1990 The Apparent Mass of the Seated Human Body in the Fore-and-aft and Lateral Directions Journal of Sound and Vibration 139 2 299 306
- Nishiyama S. 1993 Vertical and Lateral Vibration Analysis of Vehicle-Occupant Dynamic Interaction with Simulation System Transactions of the Japan Society of Mechanical Engineers 59 567 3239 3246
- Kawai K. Matsuoka Y. 2000 Construction of a Vibration Simulation Model for the Transportation of Wheelchair-Bound Passengers SAE 2000-01-0645
- Nishiyama S. 1993 Developement of Simulation System on Vehicle-Occupant Dynamic Interaction (1st Report, Theoretical Analysis and System Verification) Transactions of the Japan Society of Mechanical Engineers 59 568 3613 3621
- Nishiyama S. 1993 Developement of Simulation System on Vehicle-Occupant Dynamic Interaction (2nd Report, Influence of Sitting Posture on Human Comfort) Transactions of the Japan Society of Mechanical Engineers 59 568 3622 3629
- Nishiyama S. 1994 Developement of Simulation System on Vehicle-Occupant Dynamic Interaction (3rd Report, Influence of Parameters of Occupant-Seat System on Suman Comfort) Transactions of the Japan Society of Mechanical Engineers 60 573 1509 1516
- Kim S. K. White S. W. Bajaj A. K. Davies P. 2003 Simplified Models of the Vibration of Mannequins in Car Seats Journal of Sound and Vibration
- Cho Y. Yoon Y.-S. 2000 Determination of Seat Sponge Properties with Estimated Biodynamic Model SAE 2000-01-0640
- Singh R. Davies P. Bajaj A. 2002 Identification of Nonlinear and Viscoelastic Properties of Flexible Polyurethane Foam Nonlinear Dynamics
- Deng R. Davies P. Bajaj A. 2003 Flexible Polyurethane Foam Modeling and Identification of Viscoelastic Parameters for Automotive Seating Applications Journal of Sound and Vibration
- Ippili R. Davies P. Bajaj A. K. Hagenmeyer L. 2002 Prediction of Static Settling Point in a Seat Occupant System 5th Digital Human Modeling Conference VDI-Berichte 377 404
- White S. W. Kim S. K. Bajaj A. K. Davies P. Showers D. K. Liedtke P. E. 2000 Experimental Techniques and Identification of Nonlinear and Viscoelastic Properties of Flexible Polyurethane Foam Nonlinear Dynamics 22 281 313
- Banks H. T. Potter L. K. Zhang Y. 1996 Stress-strain Laws for Carbon Black and Silicon Filled Elasatomers Proceedings of the 36th IEEE Conference on Decision and Control 3727 3732
- Ljung L. 1999 System Identification: Theory for the User Prentice Hall
- The Math Works Inc. 05 2001 MATLAB, Version 6.1.0.450
- Greenwood Donald T. 1965 Principles of Dynamics Prentice Hall
- Waterloo Maple Inc. 01 1998 MapleV, Maple Worksheet Interface, Release 5, SUN SPARC SOLRAIS
- Muravyov A. Hutton S. G. 1997 Closed-form Solutions and the Eigenvalue Problem for Vibration of Discrete Viscoelastic Systems Journal of Applied Mechanics 64 684 691
- Singh R. 2000 Dynamic Modeling of Polyurethane Foam and Development of System Identification Methodologies Master's Thesis Purdue University, School of Mechanical Engineering
- Brenan K. E. Campbell S. L. Petzold L. R. 1996 Numerical Solution of Initial-Value Problems in Differential-Algebraic Equations SIAM Classics in Appl. Math.
- Amirouche Farid. M. L. 1992 Computational Methods in Multibody Dynamics Prentice Hall
- White S. W. 1998 Dynamic Modeling and Measurement of Occupied Car Seats and Seating Foam Master's Thesis Purdue University, School of Mechanical Engineering
- Knowledge Revolution 1996 Working Model 2D, Version 4.0