Operators of agricultural machinery are exposed to an extensive range of indirect vibrations through the seats, which gradually causes chronic damages. One of the ways to reduce the vibrations imposed on the operators is to use appropriate materials in tractor seat cushion. The present study was carried out in order to select appropriate foam or sponge and investigate different factors in reduc...

Dynamic interaction between a human body and the seat cushion was addressed, aiming at seat design for better NVH performance of a passenger vehicle. Referring to DIN EN ISO 3386-1 and previously researches, static and dynamic tests were conducted on polyurethane foams typically used as vehicle seat cushions. A one-dimensional stress strain relation was derived based on the measured data, in wh...

Original scientific paper In this paper, a method for ergonomic analysis of the seating comfort in the driver’s seat for passenger vehicles is presented in two phases. In the first phase, the comfort seating postures of the driver are analyzed considering the comfort angles for the placement of human body and the necessary space for foot controls in vehicles, as well as the ranges of adjustment...

The vibration characteristics of car seats directly influence the ride comfort. Polyurethane foam is key part a seat, and its physical parameters have an important impact on seat. In this study, thickness hardness seat cushion with different excitation magnitudes was investigated by using transmissibility effective amplitude (SEAT) value. First, tests were carried out at vertical simulator widt...

We studied the seated buttock pressure distribution in six paraplegic patients by means of computerized pressure mapping. They were all male and their age ranged from 18 to 48 years old. Their level of paralysis varied from Th5 to L1. Five kinds of wheelchair cushions were studied: an air cushion, a contour cushion, a polyurethane foam cushion, a Cubicushion (which is made of polyurethane foams...

[Purpose] The purpose of this study was to determine the best adjustable cushions, for the maintenance of normal sitting balance by healthy persons in wheelchairs, from a foam cushion, and a newly-developed air-adjustable cushion. [Subjects] Eighteen healthy participants (9 men, 9 women) were recruited. [Methods] Participants were evaluated using the Force Sensing Array System to assess average...

To protect the driver of off-highway dump trucks from the harmful vibration, this paper presents the comparison results to determine the optimal damping of the seat system by different optimization design plans. Three optimization schemes are considered including individually optimizing the damping of the cushion, individually optimizing the damping of the seat suspension, and integrately optim...

In the development of foam seats, there are many design variables and design requirements to be taken into account. In this context, numerical simulation can be a valuable tool to facilitate this process and shorten its duration by minimizing the number of test specimens built and the number of real tests made. In general, the aim is to predict the response of a seat under certain conditions an...

Shear stress measured on three different cushioning materials 1 Summary Shear force is an important component of the mechanical load on a person that is supported by a surface. Too high shear force leads to occlusion of blood flow, which is seen as one of the most important factors behind pressure sores and discomfort. In the present study the influence of three different cushioning materials (...

Effective digital human model (DHM) simulation of automotive driver packaging ergonomics, safety and comfort depends on accurate modelling of occupant posture, which is strongly related to the mechanical interaction between human body soft tissue and flexible seat components. This paper presents a finite-element study simulating the deflection of seat cushion foam and supportive seat structures...