Pressure-sensing pad test and computer simulation for the pressure distribution on the contact patch of a tyre

Author(s):  
Sujin Park ◽  
Wansuk Yoo ◽  
Jinrae Cho ◽  
Beomsoo Kang
2021 ◽  
Author(s):  
Gabriel H. Campos

The premise of this work is to address aircraft seat comfort. This thesis presents the development of an automatic morphing backrest used to reduce pressure experienced by the passenger from the seat. Uncomfortable, high surface pressure zones on the backrest can be alleviated by decentralizing the occupant’s weight. The improved pressure distribution is intended to decrease discomfort during flight while taking different comfort/discomfort models into consideration. Pressure distribution data from the embedded sensor mat is used to compute the seat’s cushion deflection and corresponding backrest contour caused by the passenger’s weight. The surfaces of interest - the passenger’s back and the seat, are modelled and discretized. The discretized surface contact pressure is integrated into the hyperelastic contact model to determine the loading profile. From this, the current pressure distribution and the cushion’s surface change are computed and used in the control system to create the corresponding actuation of the surface.


2021 ◽  

The Press-in-Place (PIP) gasket is a static face seal with self-retaining feature, which is used for the mating surfaces of engine components to maintain the reliability of the closed system under various operating conditions. Its design allows it to provide enough contact pressure to seal the internal fluid as well as prevent mechanical failures. Insufficient sealing pressure will lead to fluid leakage, consequently resulting in engine failures. A test fixture was designed to simulate the clamp load and internal pressure condition on a gasket bolted joint. A Sensor pad using TEKSCAN equipment was used to capture the overall and local pressure distribution of the PIP gasket under various engine loading conditions. Then, the Sensor pad test results were compared with simulated CAE results from computer models. Through the comparisons, it is found that the gasket sealing pressure of test data and CAE data show good correlation for bolt load condition 500N when compared to internal pressure side load condition of 0.138 MPa & 0.276 MPa. Moreover, the gasket cross-sectional pressure distribution obtained by experimental tests and CAE models correlated very well with R2 ranging from 90 to 99% for all load cases. Both CAE and Sensor pad test results shows increase in sealing pressure when internal side pressure is applied to the gasket seal.


Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 44 ◽  
Author(s):  
Wangjoo Lee ◽  
Seung-Hyeon Hong ◽  
Hyun-Woo Oh

In this paper, we propose a smart insole for inexpensive plantar pressure sensing and a simple visualizing scheme. The insole is composed of two elastomeric layers and two electrode layers where the common top electrode is submerged in the insole. The upper elastomeric layer is non-conductive poly-dimethyl-siloxane (PDMS) and supports plantar pressure buffering and the lower layer is carbon nano-tube (CNT)-dispersed PDMS for pressure sensing through piezo-resistivity. Under the lower sensing layer are 16 bottom electrodes for pressure distribution sensing without cell-to-cell interference. Since no soldering or sewing is needed the smart insole manufacturing processes is simple and cost-effective. The pressure sensitivity and time response of the material was measured and based on the 16 sensing data of the smart insole, we virtually extended the frame size for continuous and smoothed pressure distribution image with the help of a simple pseudo interpolation scheme.


Author(s):  
Ahmad Radmehr ◽  
Arash Hosseinian Ahangarnejad ◽  
Yu Pan ◽  
SayedMohammad Hosseini ◽  
Ali Tajaddini ◽  
...  

Abstract This study evaluates the wheel-rail contact patch geometry of the VT-FRA roller rig, designed and commissioned at the Virginia Tech’s Railway Technologies Laboratory (RTL). Contact patch measurements are crucial for better analyzing the underlying factors that affect the wheel-rail interface (WRI) contact mechanics and dynamics. One of the challenges is in determining the size and pressure distribution at the contact patch, under various conditions. Although past studies have attempted to reach a method that can be used to make such measurements, more research is needed in reaching a practical and consistent method. This is particularly true for making the measurements under dynamic conditions. The use of pressure sensitive films was considered as the means for contact patch measurements on the VT-FRA rig, however, the thickness of the film influences the contact patch area and shape. This paper provides the results of the measurements with films with different range of pressure sensitivities. Three types of pressure-sensitive films are used under static conditions. The films are placed in between the wheel and roller in exact positions to enable comparing the test results for various wheel loads. The contact patch measured by the most sensitive film, which reacts to pressures as low as 0.5 MPa, provides the most accurate outline for the contact patch, although it does not provide the highest resolution for the pressure distribution. The other pressure-sensitive films that are used have a higher pressure range, with minimums of 49.0 MPa and 127.6 MPa. The relationship between the size of the contact patch and average contact pressure is evaluated as a function of the wheel load. The results indicate that with increasing wheel load, the size of the contact patch changes minimally, with the average pressure increasing in a nearly linear relationship to the wheel load as expected.


1969 ◽  
Vol 42 (4) ◽  
pp. 1014-1027 ◽  
Author(s):  
D. I. Livingston ◽  
J. E. Brown

Abstract Slipping wheel theory has been extended to predict the dependence of the lateral force and of the aligning torque on the nature of the pressure distribution over the contact patch between the wheel and the ground. Expressions have been derived for both side force and aligning torque as functions of the slip angle under: uniform pressure distribution, which applies to the behavior of an inflated membrane wheel; elliptical distribution, which describes the behavior of a solid wheel; and parabolic distribution. All appear appropriate in some respect to the actual tire.


2021 ◽  
Author(s):  
Gabriel H. Campos

The premise of this work is to address aircraft seat comfort. This thesis presents the development of an automatic morphing backrest used to reduce pressure experienced by the passenger from the seat. Uncomfortable, high surface pressure zones on the backrest can be alleviated by decentralizing the occupant’s weight. The improved pressure distribution is intended to decrease discomfort during flight while taking different comfort/discomfort models into consideration. Pressure distribution data from the embedded sensor mat is used to compute the seat’s cushion deflection and corresponding backrest contour caused by the passenger’s weight. The surfaces of interest - the passenger’s back and the seat, are modelled and discretized. The discretized surface contact pressure is integrated into the hyperelastic contact model to determine the loading profile. From this, the current pressure distribution and the cushion’s surface change are computed and used in the control system to create the corresponding actuation of the surface.


2017 ◽  
Vol 62 (1) ◽  
pp. 177-188
Author(s):  
Józef Markowicz ◽  
Sylwester Rajwa ◽  
Stanisław Szweda

Abstract The problem of cooperation of powered roof support with the floor in the aspect of shaping its design is presented. From the analysis of the simplifying assumptions considered so far in the methods for determination of roof support’s base pressure on the floor, it results that they are not satisfied in the case of bases of the catamaran type, commonly used in currently manufactured roof supports. Model of cooperation of the base lying on the floor, prepared by the finite elements method is described and the results of computer simulation of the base action on the floor are given. Considering the results of numerical analyses, the factors influencing the pressure distribution of the base on the floor as well as its maximal value, have been identified.


1977 ◽  
Vol 19 (4) ◽  
pp. 135-142 ◽  
Author(s):  
J. B. Hawkyard ◽  
C. K. S. Gurnani ◽  
W. Johnson

Experiments on the rotary forging of discs are described in which measurements are taken of pressure distribution under the rocking die using a pressure-sensing platen. The results suggest a deformation mechanism for the spread of the disc, involving the development of plastic hinges away from the immediate die contact area. This would explain central tensile failures and related phenomena observed previously.


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