A Proposal of Physical Model for the Load-deflection Properties of Vehicle Polyurethane Foam

Abstract

The limited interior space in modern vehicles, driven by the adoption of EVs/HEVs and low-profile designs, necessitates new approaches to seat cushion design. Seat comfort relies on the load-deflection properties of polyurethane foam, which are difficult to predict due to their nonlinear behavior. To address this, we developed a series spring physical model to approximate these properties. Our findings show that this model's behavior aligns strongly with that of actual polyurethane foam, allowing its complex nonlinear properties to be accurately described by a simple exponential function. This model is applicable not only to foam samples but also to complex structures like full seat assemblies, offering a valuable tool for improving the efficiency of seat design and performance prediction.