Effects of seating on the discomfort caused by mechanical shocks: Measurement and prediction of SEAT values

Patelli, Giulia; Griffin, Michael J.

doi:10.1016/j.apergo.2018.08.003

Cited by 14 publications

(30 citation statements)

References 23 publications

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“…Gong et al 16 and Ciloglu et al 18 used the SEAT value as an objective indicator to evaluate the vibration isolation efficiency of train seats and airplane seats, respectively. Patelli et al 19 through the study of two different thickness foam cushion found that with vertical mechanical shocks at low, medium, and high magnitudes (0.5, 1.0, and 2.0 ms À1.75 VDV) at frequencies between 1.0 and 16 Hz, the measured SEAT values were similar to the subjective SEAT values, the measured SEAT value was a good indicator of the effect of the seat on the discomfort. The above studies show that the SEAT value is a proper indicator for the research of the seat comfort, but a clear and consistent conclusion on the relationship between the SEAT value and the foam physical parameters has not yet been achieved.…”

Section: Introductionmentioning

confidence: 78%

Transmission of vertical vibration through a seat cushion at the seat pan: Effect of foam physical properties during different excitation magnitudes

Luo,

He,

Zhang

et al. 2023

Journal of Low Frequency Noise, Vibration and Active Control

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The vibration characteristics of car seats directly influence the ride comfort. Polyurethane foam is the key part of a seat, and its physical parameters have an important impact on the seat. In this study, the influence of the foam thickness and foam hardness on the vibration characteristics of seat cushion with different excitation magnitudes was investigated by using transmissibility and seat effective amplitude transmissibility (SEAT) value. First, vibration tests were carried out at a vertical vibration simulator with width-limited white noise vibration frequencies from 0.5 to 20 Hz with root-mean-square (r.m.s.) values of 0.4, 0.8, and 1.2 m/s2, the acceleration at the platform and the body-foam interfaces were measured to calculate the transmissibility, and the influence of the foam physical properties on the transmissibility was analyzed. Then, the SEAT value was introduced to assess the vibration isolation efficiency of the foam cushion, and the influence of the foam physical properties of the foam cushion on the vibration isolation efficiency was analyzed. With increasing thickness of the foam and decreasing hardness of the foam at the seat pan, the peak transmissibility increased and the resonance frequency decreased. The SEAT values show that increasing the foam thickness is beneficial to the improvement of the vibration isolation efficiency of the seat, but there is a diminishing return; the combination of physical parameters of low hardness and high thickness could make the vibration isolation performance of the seat better. In addition, the nonlinearity of human-seat system during different vibration magnitude was found.

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Section: Introductionmentioning

confidence: 78%

Transmission of vertical vibration through a seat cushion at the seat pan: Effect of foam physical properties during different excitation magnitudes

Luo,

He,

Zhang

et al. 2023

Journal of Low Frequency Noise, Vibration and Active Control

View full text Add to dashboard Cite

show abstract

“…The vertical displacement of the suspension mass above the front and rear wheels, the displacement at the center of mass of the car body, and the pitch angle are related as follows [26]:…”

Section: Analysis Of Influence Of Vehicle Motion On Cameramentioning

confidence: 99%

Research on Quantitative Calculation Method of Lane-Line Region of Interest and Structural Constraints in Constant Speed Cruise Mode

Zhou

Wei

2021

IEEE Access

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Appropriate region of interest (ROI) and lane structure restriction conditions can improve the ac-curacy of lane detection. Most previously reported approaches require human experience to set up the constraint conditions of the ROI and lane structure. Few of these studies involved quantitative calculation methods of the constraint conditions of the ROI and lane structure. To solve this problem, constant-speed cruise mode, which relies on lane recognition, was examined. A vehicle dynamics model with a chargecoupled device (CCD) camera was constructed based on the vehicle dynamics and camera projection. The projection of lane line feature points from the world coordinate system to the image coordinate system under different vehicle positions and postures was analyzed. A quantitative calculation method of the ROI lateral constraint equation and the lane structure constraint equation in constant-speed cruise mode is given. Actual road test data showed that the constraint condition calculation method not only agreed with the actual road test results but also improved the real-time accuracy.

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“…Train seats are crucial to decrease vibration transmission from the floor to the user. Together, the seat and human body constitute a coupled complex dynamic system [14,[21][22][23]. A significant discrepancy can be observed when comparing the transmissibility of subjects with identical characteristics, including identical mass.…”

Section: Introductionmentioning

confidence: 99%

Modal Identification of Train Passenger Seats Based on Dynamic Tests and Output-Only Techniques

et al. 2023

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Railways are one of the most efficient and widely used mass transportation systems for mid-range distances, also being pointed out as the best strategy to reach European Union decarbonisation goals. However, to increase railways attractiveness, it is necessary to improve the quality of the ride, namely its comfort, by decreasing the vibration at the passenger level. This article describes the experimental vibration modal identification of train seats based on a dedicated set of dynamic tests performed on Alfa Pendular and Intercity trains. This work uses two output-only modal identification techniques: the transmissibility functions and the Enhanced Frequency Domain Decomposition (EFDD) method. The last method allows us to clearly distinguish the seat structural movements, particularly the ones related to torsion and bending of the seat frame, from the local vertical foam vibrations. The natural frequencies and mode shapes are validated by matching the results derived from the transmissibility functions and EFDD method. The identified modal parameters are particularly relevant to characterise the vibration transmissibility provided by the foams (local transmissibility) and the vibration transmissibility derived from the metallic seat frame (global transmissibility).

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Effects of seating on the discomfort caused by mechanical shocks: Measurement and prediction of SEAT values

Cited by 14 publications

References 23 publications

Transmission of vertical vibration through a seat cushion at the seat pan: Effect of foam physical properties during different excitation magnitudes

Transmission of vertical vibration through a seat cushion at the seat pan: Effect of foam physical properties during different excitation magnitudes

Research on Quantitative Calculation Method of Lane-Line Region of Interest and Structural Constraints in Constant Speed Cruise Mode

Modal Identification of Train Passenger Seats Based on Dynamic Tests and Output-Only Techniques

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