Validation of an indentor system for evaluating truck seat cushions

2003 ◽  
Vol 217 (5) ◽  
pp. 343-348 ◽  
Author(s):  
M Seigler ◽  
M Ahmadian ◽  
C Boggs
Keyword(s):  
Pressure Distribution ◽  
Dynamic Testing ◽  
Interface Pressure ◽  
Dynamic Complexity ◽  
Seat Suspension ◽  
System Validation ◽  
Seat Cushion ◽  
Seat Cushions ◽  
Heavy Truck ◽  
Variable Weighting

The objective of this study was to validate an indentor system—called a cushion loading indentor (CLI)—for use in objectively evaluating seat cushion performance for heavy truck seats. Included in this study is a detailed description of the five-component indentor design, with major components being a polyurethane buttocks mould and a variable weighting system. Validation of the CLI was performed by comparing its interface pressure distribution with five human test subjects for four different seating surfaces. The results demonstrate that the CLI is both more repeatable than the human test subjects and provides similar pressure distribution to that of a seated person. Furthermore, it is shown that the CLI is valid for dynamic testing of heavy truck seat cushions owing to the inclusion of the seat suspension, which significantly reduces the dynamic complexity between the cushion and the seated person.

scholarly journals Effects of different seat cushions on interface pressure distribution: a pilot study

2016 ◽  
Vol 28 (1) ◽  
pp. 227-230 ◽  
Author(s):  
Sang-Heon Lee ◽  
Ji-Su Park ◽  
Bong-Keun Jung ◽  
Sung-A Lee
Keyword(s):  
Pilot Study ◽  
Pressure Distribution ◽  
Interface Pressure ◽  
Seat Cushions

Characteristic Parameters of Cushion in High-Speed Train (CRH) Contribute to Seat Pressure Distribution Analysis

2013 ◽  
Vol 397-400 ◽  
pp. 593-598
Author(s):  
Wen Yu Wu ◽  
Cheng Qi Xue ◽  
Lin Dong Liu
Keyword(s):  
Pressure Distribution ◽  
High Speed ◽  
Maximum Pressure ◽  
Distribution Analysis ◽  
High Speed Train ◽  
Characteristic Parameters ◽  
Element Analysis ◽  
Reliability Design ◽  
Seat Cushion ◽  
Seat Cushions

Based on the seat cushions in high-speed train, three main characteristic parameters, surface angle, width and height are involved in this simulation experiment analysis. With this CAE method, a standard buttocks model fit to seat cushion is imported, and the study on seat pressure distribution is taken through characteristic parameters of seat cushions related to different concave surfaces using ANSYS’s finite element analysis, and contribute to much flexible and more adjustable feature points, use seat pressure distribution to determine geometric parameter according to maximum pressure points, the result in this work finally satisfy the standard of optimization, and helps to assist reliability design of seats in high speed train.

A Hybrid Multibody Model for Aircraft Occupant/Seat Cushion Crashworthiness Investigation

2005 ◽  
Author(s):  
Hamid Kh. Beheshti ◽  
Hamid M. Lankarani ◽  
Sivaraman Gopalan
Keyword(s):  
Dynamic Testing ◽  
Polyurethane Foams ◽  
Full Scale ◽  
Design Tool ◽  
General Aviation ◽  
Dynamic Responses ◽  
Crash Test ◽  
Load Path ◽  
Seat Cushion ◽  
Seat Cushions

Seat cushion is in the primary load path between the seat and the occupant, and the potential for injuries to an occupant in an accident highly depends on it. The seat cushion is able to dissipate the kinetic energy due to impact in a controlled manner. Wide varieties of energy absorbing materials are used in aircraft interiors for occupant safety and ergonomic purposes. Flexible polyurethane foams are one among those used in seat cushions. Although comfort and aesthetics play an important role in the seat cushion design, safety is among the top criteria. Studies on seat cushions have demonstrated that the seat cushions generally amplify the lumbar/pelvis transmitted load to the occupant, making the seat cushion design further complicated for crashworthy design. The certification of seat cushion requires that their performance be demonstrated by dynamic full scale sled testing. Due to the high costs involved in dynamic testing, a mathematical hybrid multi-body model is developed in this study to simulate the dynamic responses of a bare iron seat, the seat cushion and the occupant represented by crash test dummy. The model is utilized to predict the lumbar load sustained when subjected to the FAR Part 23 and 25 dynamic test conditions for transport and general aviation category aircraft. The model is also used to determine the relative displacement and velocity of occupant against the seat pan. The results from the dynamic model are validated with full-scale sled tests performed at the National Institute for Aviation Research (NIAR), and hence can be utilized as a design tool for the selection of proper seat cushions.

scholarly journals A study on damage to mechanical seat cushion made from different materials of extension frame

2018 ◽  
Vol 7 (3.3) ◽  
pp. 315
Author(s):  
Jae Won Kim ◽  
Jae Ung Cho ◽  
Chan Ki Cho ◽  
Jin Oh Kim
Keyword(s):  
Shear Stress ◽  
Statistical Analysis ◽  
Material Property ◽  
Equivalent Stress ◽  
Damage Prediction ◽  
Seat Cushion ◽  
Seat Cushions

Background/Objectives: : Automotive seat is a very important component to prevent accidents by reducing passenger’s tiredness, thus, this study worked on analyzing damage with different materials of extension frames of mechanical seat cushions.Methods/Statistical analysis: In this study, we performed an experiment on cushion extension frames by splitting it into two parts. We studied about the damage prediction of slave body for each material property of ABS, PP, PLA, and PA6.6. For analyzing the condition, we assigned the side part of the master body for fixed support, and we progressed on analysis by applying with 690N on the entire part of the slave body.Findings: This research worked on the study of damage to different materials of extension frames of seat cushions. After confirming the stress equivalence of the entire model for each material, PP showed the highest equivalent stress of 180.88MPa, and ABS showed the lowest equivalent stress of 151.73MPa. Overall, we could see that in the order of ABS, PA6.6, PLA, PP have a higher tendency to be broken. In addition, when confirming equivalent stress of master body depending on materials of slave body, PA6.6 showed the highest equivalent stress of 166.3MPa, and ABS showed the lowest equivalent stress of 124.06MPa. Overall, we could see that in the order of ABS, PP, PLA and PP6.6 have a higher tendency to be broken. In comparing shear stress on the gear part, which has the highest tendency to be broken in among the entire model, depending on the material of the slave body, PLA showed the greatest shear stress of 88.945MPa, and ABS showed the lowest shear stress of 69.766MPa.Improvements/Applications: This study worked for the improvements and applications of cushion extension frames as the securement of material by investigating these factors.  

Interface pressure distribution of elderly Japanese people in the sitting position

2011 ◽  
Vol 6 (1) ◽  
pp. 38-46 ◽  
Author(s):  
Masaya Urasaki ◽  
Gojiro Nakagami ◽  
Hiromi Sanada ◽  
Atsuko Kitagawa ◽  
Etsuko Tadaka ◽  
...  
Keyword(s):  
Pressure Distribution ◽  
Sitting Position ◽  
Interface Pressure ◽  
Japanese People ◽  
Elderly Japanese

No-Jerk Skyhook Control Methods for Semiactive Suspensions

2004 ◽  
Vol 126 (4) ◽  
pp. 580-584 ◽  
Author(s):  
Mehdi Ahmadian ◽  
Xubin Song ◽  
Steve C. Southward
Keyword(s):  
Relative Velocity ◽  
Magnetorheological Damper ◽  
Damping Force ◽  
Electrical Currents ◽  
Zero Crossings ◽  
Seat Suspension ◽  
Suspension Systems ◽  
Heavy Truck ◽  
The Relationship ◽  
Study Offer

This paper presents two alternative implementations of skyhook control, named “skyhook function” and “no-jerk skyhook,” for reducing the dynamic jerk that is often experienced with conventional skyhook control in semiactive suspension systems. An analysis of the relationship between the absolute velocity of the sprung mass and the relative velocity across the suspension are used to show the damping-force discontinuities that result from the conventional implementation of skyhook control. This analysis shows that at zero crossings of the relative velocity, conventional skyhook introduces a sharp increase (jump) in damping force, which, in turn, causes a jump in sprung-mass acceleration. This acceleration jump, or jerk, causes a significant reduction in isolation benefits that can be offered by skyhook suspensions. The alternative implementations of skyhook control included in this study offer modifications to the formulation of conventional skyhook control such that the damping force jumps are eliminated. The alternative policies are compared to the conventional skyhook control in the laboratory, using a base-excited semiactive system that includes a heavy-truck seat suspension. An evaluation of the damping force, seat acceleration, and the electrical currents supplied to a magnetorheological damper, which is used for this study, shows that the alternative implementations of skyhook control can entirely eliminate the damping-force discontinuities and the resulting dynamic jerks caused by conventional skyhook control.

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