Factors affecting static seat cushion comfort

Area of Science:

• Automotive Engineering
• Human Factors Engineering
• Materials Science

Background:

• Automobile seat comfort is crucial for driver well-being and performance.
• Understanding static comfort factors is essential for designing better seating solutions.
• Existing research has not fully elucidated the relationship between cushion properties and subjective comfort.

Purpose of the Study:

• To investigate the relationship between static physical characteristics of seat cushions and perceived comfort.
• To identify key factors influencing automobile seat cushion comfort in the absence of vibration.
• To correlate objective cushion measurements with subjective comfort evaluations.

Main Methods:

• Used Scheffe's method of paired comparisons to evaluate comfort of four automobile cushions with varying foam compositions but same hardness.
• Correlated comfort judgments with sample stiffness derived from force-deflection curves (at 490 N).
• Measured and compared buttock pressures with comfort judgments, focusing on the area beneath the ischial bones.

Main Results:

• Cushions with lower stiffness were perceived as more comfortable when foam hardness was constant.
• No linear relationship was found between stiffness and comfort for foams of the same composition but varying hardness.
• Lower total pressure under the ischial bones correlated significantly with higher comfort ratings.

Conclusions:

• Static seat cushion comfort is influenced by 'bottoming feeling' (related to stiffness at 490 N) and 'foam hardness feeling' (related to low-force foam characteristics).
• Pressure distribution beneath the ischial bones serves as a reliable indicator of both identified comfort factors.
• Minimizing pressure under the ischial bones is key to enhancing static seat comfort in automobiles.