Correlation Between Road Wear of Tires and Computer Road Wear Simulation Using Laboratory Abrasion Data

2004 ◽  
Vol 77 (5) ◽  
pp. 791-814 ◽  
Author(s):  
K. A. Grosch

Abstract Any laboratory abrasion method has to take account of the well known fact that the ranking and wear rating of tire tread compounds depend strongly on the testing conditions. The severity of road tests, particularly when carried out with customer vehicles is not well defined. Any result obtained in this way is a spot reading which contains no information about its general validity. A road wear computer program was designed which is able to simulate a very wide range of road wear testing severities and the effect which they have on achievable mileage and wear rating of tread compounds. The program uses the laboratory abrasion test system designed to be used with the Laboratory Abrasion Tester designated as LAT 100. It is shown that good agreement is obtained with actual road test results, not only for the rating of compounds but also for the achieved mileages.

Author(s):  
Matthew Laney ◽  
Ronald Farrell

Computational Fluid Dynamics (CFD) is increasingly being used as a reliable method for determining flow characteristics of a wide range of flow situations. This paper presents an extension of paper PVP2017-66269, “Check Valve Flow and Disk Lift Simulation Using CFD” [1], and utilizes some of the same concepts to characterize flow through piston-lift check valves. The previous example considered a swing check valve involving rotational movement; this example considers a vertical lift piston check valve involving translational movement. Specifically, CFD was used to determine valve flow coefficients (CV) as a function of disk lift position as well as to determine the flow rate required to achieve full open or predict intermediate disk lift positions. The CFX application, which is part of the ANSYS suite of finite element software, was used to determine the flow characteristics. As presented in PVP2017-66269, balancing flow-induced forces on the check element and considering the disk assembly weight, the valve lift behavior can be predicted. Results from the CFX analysis were compared to recent test results of a skirted disk-piston check valve and previous test results of a standard disk-piston check valve. The results showed good agreement in most cases. This validates that flow characteristics across valves with different types of check elements at different disk lift positions can be reliably predicted using CFD analysis. It is important to note that while the test results and CFD analysis showed good agreement, it was vital that actual testing be performed in order to validate the approach. This follows the recommendation outlined in the previous paper.


1983 ◽  
Vol 56 (4) ◽  
pp. 838-844 ◽  
Author(s):  
G. S. Fielding-Russell ◽  
R. L. Rongone

Abstract Mechanical fatigue results of three rubber systems, obtained by using a Painter adhesion testpiece, modified in such a way that it mates rubber-rubber surfaces (rather than metal-rubber surfaces) indicated that the testpiece is capable of fatiguing a rubber-rubber interface and therefore is useful for evaluating rubber-rubber joints. The mode of failure, correlation of the present results with static interfacial results, and the wide range of crack growth constants all indicated interfacial fatiguing. Test results, i.e., time to failure versus applied dynamic load, gave good agreement with established rubber fracture theory.


2016 ◽  
Vol 40 (1) ◽  
pp. 11-21 ◽  
Author(s):  
Md Hossain Sahadath ◽  
Ripan Biswas ◽  
Md Fazlul Huq ◽  
Abdus Sattar Mollah

The mass attenuation coefficients (?/?) of locally developed ilmenite-magnetite (I-M) concrete over a wide range of photon energy were calculated analytically using Matlab and compared with the values obtained from widely used XCom computer program. A good agreement between the calculated and XCom generated value was found. The linear attenuation coefficients and relaxation lengths were calculated for the same energy range. The transmission curves were drawn for some common gamma-ray energies and half value layer and tenth value layer were calculated. The results of this study will provide some useful information about the shielding material data base for practical shielding calculation. The results will also illustrate the effectiveness of I-M concrete so far as its shielding properties are concerned.Journal of Bangladesh Academy of Sciences, Vol. 40, No. 1, 11-21, 2016


2017 ◽  
Vol 30 (1) ◽  
pp. 86-92 ◽  
Author(s):  
Jenny Frössling ◽  
Anna Rosander ◽  
Camilla Björkman ◽  
Katarina Näslund ◽  
Märit Pringle

Digital dermatitis (DD) in dairy cows is a widespread disease linked to infection with Treponema. The traditional diagnostic method is clinical inspection, which is subjective and laborious. We explored the performance of 4 different immunogenic proteins from Treponema phagedenis in a new antibody ELISA for analysis of serum or milk. Analysis of samples from 390 cows in 25 herds showed that the ELISA could distinguish the majority of cows with DD from healthy cows. By changing the cutoff and applying parallel or serial testing, high sensitivity or specificity could be achieved. The investigation indicated that aggregated test results can be useful in the assessment of a herd’s DD status. In addition, analysis of bulk tank milk samples showed good agreement with results from individual cows. The test system could be useful in research on the epidemiology and immunology of DD.


1979 ◽  
Vol 6 (2) ◽  
pp. 268-275
Author(s):  
H. K. Ha ◽  
N. El-Hakim ◽  
P. Fazio

A refined yet simple method is presented for the analysis of cold-formed metal shear diaphragms. Expressions for the deflections and fastener forces are developed based on an assumed mode of deformation in conjunction with a refined set of internal force distributions. The formulas are applicable to both 'direct' and 'indirect' shear-transfer cases. The generality and the accuracy of the derived expressions are illustrated in an application of the method to the analysis of eight diaphragms having a wide range of constructional details. The results of calculations for the diaphragm flexibility and strength are in good agreement with test results and with finite-element analyses.


2020 ◽  
Vol 499 (3) ◽  
pp. 4418-4431 ◽  
Author(s):  
Sujatha Ramakrishnan ◽  
Aseem Paranjape

ABSTRACT We use the Separate Universe technique to calibrate the dependence of linear and quadratic halo bias b1 and b2 on the local cosmic web environment of dark matter haloes. We do this by measuring the response of halo abundances at fixed mass and cosmic web tidal anisotropy α to an infinite wavelength initial perturbation. We augment our measurements with an analytical framework developed in earlier work that exploits the near-lognormal shape of the distribution of α and results in very high precision calibrations. We present convenient fitting functions for the dependence of b1 and b2 on α over a wide range of halo mass for redshifts 0 ≤ z ≤ 1. Our calibration of b2(α) is the first demonstration to date of the dependence of non-linear bias on the local web environment. Motivated by previous results that showed that α is the primary indicator of halo assembly bias for a number of halo properties beyond halo mass, we then extend our analytical framework to accommodate the dependence of b1 and b2 on any such secondary property that has, or can be monotonically transformed to have, a Gaussian distribution. We demonstrate this technique for the specific case of halo concentration, finding good agreement with previous results. Our calibrations will be useful for a variety of halo model analyses focusing on galaxy assembly bias, as well as analytical forecasts of the potential for using α as a segregating variable in multitracer analyses.


2021 ◽  
pp. 1-11
Author(s):  
Liu Narengerile ◽  
Li Di ◽  

At present, the college English testing system has become an indispensable system in many universities. However, the English test system is not highly humanized due to problems such as unreasonable framework structure. This paper combines data mining technology to build a college English test framework. The college English test system software based on data mining mainly realizes the computer program to automatically generate test papers, set the test time to automatically judge the test takers’ test results, and give out results on the spot. The test takers log in to complete the test through the test system software. The examination system software solves the functions of printing test papers, arranging invigilation classrooms, invigilating teachers, invigilating process, collecting test papers, scoring and analyzing test papers in traditional examinations. Finally, this paper analyzes the performance of this paper through experimental research. The research results show that the system constructed in this paper has certain practical effects.


Author(s):  
Tom Jansen ◽  
Martin Gathen ◽  
Amadeo Touet ◽  
Hans Goost ◽  
Dieter Christian Wirtz ◽  
...  

Abstract Introduction During the current COVID-19 pandemic video consultations are increasingly common in order to minimize the risk of infection for staff and patients. The aim of this study was to evaluate the feasibility of a spine examination via video. Methods A total of 43 patients were recruited. Each participant underwent a video-based (VB) and a conventional face-to-face (FTF) spine examination. Pain intensity, active range of motion, inspection, a neurophysiologic basic exam and provocations tests were evaluated using video-based and face-to-face methods. Results The intra-rater reliability (IRR) was measured between both examinations. Good to very good IRR values were obtained in inspection (Kappa between 0,752 und 0,944), active range of motion and basic neurophysiological examination (Kappa between 0,659 und 0,969). Only moderate matches were found in specific provocation tests (Kappa between 0,407 und 0,938). A video-based spine examination is a reliable tool for measuring pain intensity, active range of motion and a basic neurophysiologic exam. Conclusion A basic spine examination during a video consultation is possible. A good agreement of the test results between video-based and face-to-face examination could be found.


Author(s):  
Yuan-Ting Lin ◽  
Chyuan-Yow Tseng ◽  
Jao-Hwa Kuang ◽  
Yeong-Maw Hwang

The combined brake system (CBS) is a mechanism that links the front and rear brakes for scooters. For two-wheeled scooters, a CBS with appropriate braking force distribution can reduce the risk of crashing accidents due to insufficient driving proficiency. The design of the braking force distribution for a CBS is challenging to the designer because it has to fulfill many requirements such as braking performance, ride comfort, reliability, and low costs. This paper proposes a systematic method to optimize the parameters of CBS. The evaluation indexes for the design are first discussed. The steps to determine the critical parameter to meet the indexes and a method to predict braking performance are developed. Finally, driving tests are carried out to verify the effectiveness of the proposed method. Experimental results showed that the deceleration of the tested scooter equipped with the designed CBS achieves an average mean fully developed deceleration (MFDD) of 5.246 m/s2, higher than the homologation requirement. Furthermore, the proposed method’s prediction of braking performance is in good agreement with the test results, with errors <1%.


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