Load deflection testing is one type of test that can be used to understand the comfort performance of a complete trimmed automotive seat. This type of testing can be conducted on different areas of the seat and is most commonly used on the seatback, the seat cushion and the head restraint. Load deflection data can be correlated to a customer’s perception of the seat, providing valuable insight for the design and development team. There are several variables that influence the results obtained from this type of testing. These can include but are not limited to: seat structure design, suspension system, component properties, seat materials, seat geometry, and test set-up.
Set-up of the seat for physical testing plays a critical role in the final results. This paper looks at the relationship of the load deflection data results on front driver vehicle seatbacks in a supported and unsupported test set-up condition. The SAE J2896 recommends bracing the seatback for seats with recliner mechanism during load deflection testing to minimize contribution of the recliner to the measurement. It is argued, however, that the SAE test setup method of bracing the seatback does not well represent the reality of what an occupant would feel. Although unsupported seatback test setup would introduce additional variables to the test data, it would best represent the experience of the consumer. The supported method reduces the number of variables associated with the results however may not be as correlated to customer perceptions. Load deflection test results comparing the same set of seats utilizing both methods will be compared. Recommendations for a preferred method will be provided.