System Identification of Quasi-static Foam Behavior and its Application in H-point Prediction School of Mechanical Engineering, Purdue University

Format:

Conference/Event

Author/Creator:

Ippili, Rajani K., author.

Conference Name:

Digital Human Modeling for Design and Engineering Conference and Exhibition (2003-06-16 : Montreal, Canada)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2003

Summary:

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

Notes:

Vendor supplied data

Publisher Number:

2003-01-2207

Access Restriction:

Restricted for use by site license