Load, Speed and Inflation Pressure Effects on Rolling Loss Distribution in Automobile Tires

1988 ◽  
Vol 16 (2) ◽  
pp. 78-95 ◽  
Author(s):  
J. D. Clark ◽  
D. J. Schuring

Abstract The effect of tire load, speed, and cold inflation pressure on the rolling loss contribution of any tire region is determined by numerical calculations involving both laboratory measurements and thermal modeling techniques. Laboratory measurements include tire surface temperature distributions obtained from an infrared camera system; thermal modeling is based on finite-difference procedures. Results are presented in two formats: (1) plots of rolling loss distributions from bead to bead and (2) contributions of tread, shoulder, sidewall, and bead regions. The first format is a direct result of the thermal model; the second is derived from multiple-regression operations. Both formats are given as functions of load, cold inflation pressure, and speed. Beahvior in the tread region is shown to be unique.

2005 ◽  
Vol 290 ◽  
pp. 54-61 ◽  
Author(s):  
A. Platzer ◽  
Peter Supancic ◽  
C. Lembacher ◽  
U. Theiszl ◽  
Robert Danzer

PTCs are electrical resistors (thermistors) with a positive temperature coefficient. They change their resistivity up to seven orders of magnitude within a certain temperature range. Though these parts are only loaded electrically, they often fail due to thermo-mechanical stresses caused by Joule self heating. With the aid of an infrared camera system the temperature distributions of PTCs in service were investigated. They show a big variety in appearance, often strongly differing from the temperature distribution predicted by a model-calculation using homogenous material properties. The temperature distributions measured with the infrared system give information about gradients in material properties. Performing destructive tests by high electrical loading lead to fractures, which are initiated in the most stressed regions. Fractography was used to identify fracture origins. With the information of the fractography and thermal analysis of the infrared camera the FEM-model could be modified in order to understand different kind of fracture modes.


2021 ◽  
Vol 10 (12) ◽  
pp. 2595
Author(s):  
Ryo Karakawa ◽  
Hidehiko Yoshimatsu ◽  
Keisuke Kamiya ◽  
Yuma Fuse ◽  
Tomoyuki Yano

Background: Lymphaticovenular anastomosis (LVA) is a challenging procedure and requires a sophisticated supermicrosurgical technique. The aim of this study was to evaluate and establish a discrete supermicrosurgical anastomosis method using the “suture-stent technique”. Methods: Forty-eight LVA sites of twenty patients with lower extremity lymphedema who had undergone LVA between July 2020 and January 2021 were included in this study. LVA was performed with the conventional technique or with the suture-stent technique. The patency of the anastomoses was evaluated using an infrared camera system intraoperatively. The success rate on the first try and the final success rate for each group were compared. Results: After full application of the exclusion criteria, 35 LVAs of 16 patients including 20 limbs were included in the analysis. The ratio of good patency findings after anastomosis in the suture-stent technique group was 100%. The incidences of leakage or occlusion on the first try were statistically greater in the conventional technique group (29.4%) than in the suture-stent technique group (0%) (p = 0.0191). All anastomoses achieved good patency in the final results. Conclusion: With its minimal risk of catching the back wall during the anastomosis, the suture-stent technique can be considered an optimal anastomosis option for LVA.


2016 ◽  
Vol 869 ◽  
pp. 411-415
Author(s):  
Dimitry V. Bubnoff ◽  
Mariana M.O. Carvalho ◽  
Carlos Roberto Xavier ◽  
Gláucio S. da Fonseca ◽  
José Adilson de Castro

In the present work, the martensite formation during heat treatment of 1026 steel was studied in order to acquire process knowledge and reinforce the effectiveness of infrared thermography method to evaluate the temperature distributions. Several tests were carried out and monitored by an infrared camera and thermocouples. Martensite fraction was evaluated with the aid of the Koistinen-Marburger model and adequate parameters describing phase transformations were obtained for 1026 steel samples. This research revealed the need of model adjustment in order to accurately describe the martensite transformation kinetics according to experimental results.


Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6659
Author(s):  
Aryuanto Soetedjo ◽  
Evy Hendriarianti

A non-destructive method using machine vision is an effective way to monitor plant growth. However, due to the lighting changes and complicated backgrounds in outdoor environments, this becomes a challenging task. In this paper, a low-cost camera system using an NoIR (no infrared filter) camera and a Raspberry Pi module is employed to detect and count the leaves of Ramie plants in a greenhouse. An infrared camera captures the images of leaves during the day and nighttime for a precise evaluation. The infrared images allow Otsu thresholding to be used for efficient leaf detection. A combination of numbers of thresholds is introduced to increase the detection performance. Two approaches, consisting of static images and image sequence methods are proposed. A watershed algorithm is then employed to separate the leaves of a plant. The experimental results show that the proposed leaf detection using static images achieves high recall, precision, and F1 score of 0.9310, 0.9053, and 0.9167, respectively, with an execution time of 551 ms. The strategy of using sequences of images increases the performances to 0.9619, 0.9505, and 0.9530, respectively, with an execution time of 516.30 ms. The proposed leaf counting achieves a difference in count (DiC) and absolute DiC (ABS_DiC) of 2.02 and 2.23, respectively, with an execution time of 545.41 ms. Moreover, the proposed method is evaluated using the benchmark image datasets, and shows that the foreground–background dice (FBD), DiC, and ABS_DIC are all within the average values of the existing techniques. The results suggest that the proposed system provides a promising method for real-time implementation.


2020 ◽  
Vol 10 (9) ◽  
pp. 3156 ◽  
Author(s):  
Andrew Dressel ◽  
James Sadauckas

Mountain bikes continue to be the largest segment of U.S. bicycle sales, totaling some USD 577.5 million in 2017 alone. One of the distinguishing features of the mountain bike is relatively wide tires with thick, knobby treads. Although some work has been done on characterizing street and commuter bicycle tires, little or no data have been published on off-road bicycle tires. This work presents laboratory measurements of inflated tire profiles, tire contact patch footprints, and force and moment data, as well as static lateral and radial stiffness for various modern mountain bike tire sizes including plus size and fat bike tires. Pacejka’s Motorcycle Magic Formula tire model was applied and used to compare results. A basic model of tire lateral stiffness incorporating individual tread knobs as springs in parallel with the overall tread and the inflated carcass as springs in series was derived. Finally, the influence of inflation pressure was also examined. Results demonstrated appreciable differences in tire performance between 29 × 2.3”, 27.5 × 2.8”, 29 × 3”, and 26 × 4” knobby tires. The proposed simple model to combine tread knob and carcass stiffness offered a good approximation, whereas inflation pressure had a strong effect on mountain bike tire behavior.


2019 ◽  
Vol 630 ◽  
pp. A2 ◽  
Author(s):  
P. Heinisch ◽  
H.-U. Auster ◽  
B. Gundlach ◽  
J. Blum ◽  
C. Güttler ◽  
...  

Context. The landing and rebound of the Philae lander, which was part of the ESA Rosetta mission, enabled us to study the mechanical properties of the surface of comet 67P/Churyumov-Gerasimenko, because we could use Philae as an impact probe. Aims. The aim is to approximate the descent and rebound trajectory of the Philae lander and use this information to derive the compressive strength of the surface material from the different surface contacts and scratches created during the final touchdown. Combined with laboratory measurements, this can give an insight into what comets are made of and how they formed. Methods. We combined observations from the ROMAP magnetometer on board Philae with observations made by the Rosetta spacecraft, particularly by the OSIRIS camera system and the RPC-MAG magnetometer. Additionally, ballistic trajectory and collision modeling was performed. These results are placed in context using laboratory measurements of the compressibility of different materials. Results. It was possible to reconstruct possible trajectories of Philae and determine that a pressure of ~100 Pa is enough to compress the surface material up to a depth of ~20 cm. Considering all errors, the derived compressive strength shows little dependence on location, with an overall upper limit for the surface compressive strength of ~800 Pa.


Author(s):  
Satoru Yokoi ◽  
Jun Takahashi ◽  
Shigetoshi Tokita

1997 ◽  
Vol 119 (2) ◽  
pp. 153-158 ◽  
Author(s):  
D. T. Tompkins ◽  
S. A. Klein ◽  
R. A. Steeves

An approach to the treatment of medium-sized choroidal melanomas combines radiation with ferromagnetic hyperthermia. The study herein discusses results with a numerical thermal model of a choroidal melanoma in the rabbit eye as treated with episcleral, thermoradiotherapy plaques. The sensitivity of a temperature–dependent blood perfusion model is investigated.


1997 ◽  
Vol 119 (3) ◽  
pp. 604-610 ◽  
Author(s):  
B. L. Owsenek ◽  
J. Seyed-Yagoobi

Heat and mass transfer between a surface and the surrounding gas can be enhanced by the application of electric body forces that induce jet or plume-like fluid motion. Such enhancement causes no noise or vibration, can be applied in complex, isolated geometries, and allows simple control of surface temperatures. This paper examines the potentially useful case of multiple fine-wire electrodes suspended in the open air above a grounded and heated horizontal surface. An infrared camera system was used to obtain a complete and accurate distribution of local heat transfer coefficients on the impingement surface. A numerical code was developed and verified by comparison with experimental data. This code was then used to investigate and compare the heat transfer generated by novel electrode geometries.


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