scholarly journals Effects of Temperature, Time, Magnesium, and Copper on the Wettability of Al/TiC System

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Halil Ibrahim Kurt ◽  
Murat Oduncuoglu
Keyword(s):  
Explicit Form ◽  
Test Results ◽  
Mathematical Formula ◽  
Wetting Behavior ◽  
Proposed Model ◽  
Input Parameters ◽  
Effects Of Temperature ◽  
Wetting Process ◽  
Temperature Time ◽  
Good Agreement

The effects of temperature, time, and the additions of magnesium and copper on the wetting behavior of Al/TiC are studied theoretically. Mathematical formula is presented in explicit form. The effect of each variable is investigated by using the obtained equation. It is observed that the time and temperature have a stronger effect on the wetting of TiC in comparison to other input parameters. The proposed model shows good agreement with test results and can be used to find the wetting behavior of Al/TiC. The findings led to a new insight of the wetting process of TiC.

Analytical Model for Rockfall Protection Galleries - a Blind Prediction of Test Results and Conclusion

2011 ◽  
Vol 82 ◽  
pp. 722-727 ◽  
Author(s):  
Kristian Schellenberg ◽  
Norimitsu Kishi ◽  
Hisashi Kon-No
Keyword(s):  
Degrees Of Freedom ◽  
Large Scale ◽  
Test Results ◽  
Blind Prediction ◽  
Proposed Model ◽  
Input Parameters ◽  
Scale Test ◽  
Definition Of ◽  
Protective Structures ◽  
Cushion Layer

A system of multiple degrees of freedom composed out of three masses and three springs has been presented in 2008 for analyzing rockfall impacts on protective structures covered by a cushion layer. The model has then been used for a blind prediction of a large-scale test carried out in Sapporo, Japan, in November 2009. The test results showed substantial deviations from the blind predictions, which led to a deeper evaluation of the model input parameters showing a significant influence of the modeling properties for the cushion layer on the overall results. The cushion properties include also assumptions for the loading geometry and the definition of the parameters can be challenging. This paper introduces the test setup and the selected parameters in the proposed model for the blind prediction. After comparison with the test results, adjustments in the input parameters in order to match the test results have been evaluated. Conclusions for the application of the model as well as for further model improvements are drawn.

scholarly journals A Novel Fatigue Damage Model of Rock considering Temperature Effects

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Yaoliang Zhu ◽  
Jin Yu ◽  
Yanyan Cai ◽  
Xin Tang ◽  
Wei Yao ◽  
...  
Keyword(s):  
Fatigue Damage ◽  
Stress Ratio ◽  
Damage Model ◽  
Model Parameters ◽  
Test Results ◽  
Rock Fatigue ◽  
Proposed Model ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Cyclic Damage

The deformation rules and failure types of rock fatigue damage at different temperatures are quite different, and existing constitutive theory cannot describe them quantitatively. A novel rock fatigue damage model considering the effects of temperature was presented based on phenomenology. In this model, the residual strain method was used to define the fatigue damage, and the Harris attenuation function was introduced to characterize the cyclic damage evolution. The proposed model has considered the influence of the initial damage and temperature, and the model parameters can be easily calculated. The accuracy of the model was verified by comparing the calculated values of cyclic upper strain and fatigue life with previous test results. The physical significance of the model parameters shows that parameter a is related to fatigue stress ratio and lithology, while parameter b is related to temperature. The study has some reference values for the fatigue damage model of rock considering the influence of temperature.

Mathematical Modeling of Ultra-High-Pressure Waterjet Peening

2005 ◽  
Vol 127 (2) ◽  
pp. 186-191 ◽  
Author(s):  
S. Kunaporn ◽  
M. Ramulu ◽  
M. Hashish
Keyword(s):  
Mathematical Modeling ◽  
High Pressure ◽  
High Cycle Fatigue ◽  
Fatigue Tests ◽  
Analytical Models ◽  
Test Results ◽  
Ultra High Pressure ◽  
Proposed Model ◽  
Compressive Residual Stresses ◽  
Good Agreement

Waterjet peening is a recent promising method in surface treatment. It has the potential to induce compressive residual stresses that benefit the fatigue life of materials similar to the conventional shot peening process. However, there are no analytical models that incorporate process parameters (i.e., supply pressure, jet exposure time, and nozzle traverse rate, etc) to allow predicting the optimized peening process. Mathematical modeling of high-pressure waterjet peening was developed in this study to describe the relation between the waterjet peening parameters and the resulting material modifications. Results showed the possibility of using the proposed mathematical model to predict an initial range for effective waterjet peening under the variation of waterjet peening conditions. The high cycle fatigue tests were performed to validate the proposed model and fatigue test results showed good agreement with the predictions.

Predicting the Strength of Rectangular Reinforced Concrete Columns Confined with FRP Sheets

2022 ◽  
Vol 906 ◽  
pp. 17-23
Author(s):  
Ashot G. Tamrazyan ◽  
Yehia A.K. Sayed
Keyword(s):  
Compressive Strength ◽  
Regression Analysis ◽  
Concrete Columns ◽  
Test Results ◽  
Rc Columns ◽  
New Model ◽  
Proposed Model ◽  
Axial Compressive Strength ◽  
Frp Sheet ◽  
Good Agreement

A complete reorganization about the behavior of rectangular RC columns confined with FRP sheet is very important to predict the axial compressive strength values of the strengthened rectangular RC columns. That is because the process of strengthening RC rectangular column depending on several parameters that role this type of strengthening. These parameters include the characteristics of the used fiber, the grade of concrete and the geometry of the cross section including the rectangularity aspect ratio, corner radius, and size of specimens. Besides that, using a wide scope of experimental data may affect positively to generalize a model that considers the whole parameters affect the value of the axial strength. So, in this paper a review about parameters that affect the axial compressive strength values of rectangular RC columns was conducted. After that, based on the test results regarding FRP-confined rectangular RC columns available in the literature or conducted by the author, some existing confinement models for rectangular RC columns were assessed. Further, a new model is proposed through regression analysis of the database. A new model is proposed through regression analysis of the database. The proposed model was found to be in good agreement with the test results in the database. Finally, based on the results conclusions were drawn.

Model for predicting displacement-dependent lateral earth pressure

2009 ◽  
Vol 46 (8) ◽  
pp. 969-975 ◽  
Author(s):  
Guoxiong Mei ◽  
Qiming Chen ◽  
Linhui Song
Keyword(s):  
Earth Pressure ◽  
The State ◽  
Passive State ◽  
Test Results ◽  
Lateral Earth Pressure ◽  
The Earth ◽  
Proposed Model ◽  
Pressure Changes ◽  
The Relationship ◽  
Good Agreement

A model for predicting displacement-dependent lateral earth pressure was proposed based on an earth pressure – displacement relationship commonly observed in practice. The proposed model is a monotonically increasing and bounded function, with an inflection point at the displacement of s = 0 at which the earth pressure changes from the intermediate active state (the state between active and at-rest) to the intermediate passive state (the state between at-rest and passive). The proposed model can predict the relationship between earth pressure and retaining structure movement for any condition intermediate to the active and passive states, which was verified by the experimental data reported in published literature. The predicted lateral earth pressure coefficients are in good agreement with the test results of model tests reported in the literature.

Tension Fatigue Model for Helically Armored Cables

1988 ◽  
Vol 110 (1) ◽  
pp. 12-18 ◽  
Author(s):  
R. H. Knapp ◽  
E. Y. C. Chiu
Keyword(s):  
Contact Stresses ◽  
Power Cables ◽  
Test Results ◽  
Hertz Contact ◽  
Physical Test ◽  
Axial Tension ◽  
Proposed Model ◽  
Fatigue Model ◽  
Cross Wire ◽  
Good Agreement

A fatigue model which predicts cycles-to-failure for helically armored cables subjected to fluctuating axial tension is proposed. Electrical-optical communication cables, power cables, and bridge and track strands normally derive structural strength from two or more layers of round steel wires contrahelically laid around a cylindrical core. In cases where wires are laid in direct contact with wires in adjacent layers, Hertz contact stresses produce wire failures leading to ultimate cable failure at tensions well below the static breaking strength. The proposed model treats cross-wire Hertz contact stresses as equivalent geometric notches in conjunction with the numerical solution of the governing helical wire cable equations. Model and physical test results show good agreement.

scholarly journals Experimental Study on Lateral-Load-Resisting Capacity of Masonry-Infilled Reinforced Concrete Frames

2021 ◽  
Vol 11 (21) ◽  
pp. 9950
Author(s):  
Minjae Kim ◽  
Eunjong Yu
Keyword(s):  
Shear Failure ◽  
Masonry Wall ◽  
Experimental Program ◽  
Test Results ◽  
Concrete Frames ◽  
Masonry Infill ◽  
Proposed Model ◽  
Current Code ◽  
Adequate Method ◽  
Good Agreement

In this study, an experimental program was performed on masonry-infilled frame specimens with varied construction precision and masonry thickness. A total of five portal frame specimens, which consist of four masonry-infilled frames and a bare frame, were tested, and the results were analyzed to investigate the effects of construction precision and interaction between the masonry infill and the frame. The test results indicated that the gap in the masonry infill decreased strength by 75% to 80% and stiffness by 55% to 70%. A comparison between the measured and predicted peak strength using the current code shows that the code equations underestimate the strength by up to 70%. This is due to the fact that the contribution of friction in shear resistance of the masonry wall is actually ignored in the current code since no adequate method for estimating the normal force is provided. In addition, reflecting the observation that the failure mode of the columns changed to shear failure when thick masonry walls were used, a mechanical model that can explain the shear failure and enables the estimation of maximum strength was proposed. The maximum strengths of the specimens calculated using the proposed model were in good agreement with the experimental results.

Deformation behaviour of clay under repeated one-dimensional unloading–reloading

2015 ◽  
Vol 52 (8) ◽  
pp. 1035-1044 ◽  
Author(s):  
Apichat Suddeepong ◽  
Jinchun Chai ◽  
Shuilong Shen ◽  
John Carter
Keyword(s):  
Clayey Soil ◽  
Deformation Behaviour ◽  
Permanent Deformation ◽  
Field Measurements ◽  
Test Results ◽  
One Dimensional ◽  
Groundwater Fluctuation ◽  
Proposed Model ◽  
Oedometer Tests ◽  
Good Agreement

The deformation of clayey soil under repeated cycles of unloading and reloading has been investigated in oedometer tests using both undisturbed and reconstituted Ariake clay samples. The test results indicate that even for repeated unloading–reloading in the overconsolidated stress range, the deformation of the soil sample is not purely elastic and there is an accumulation of permanent deformation. Based on the test results, a model has been proposed for predicting unloading–reloading-induced deformation. The proposed model has been used to simulate the behaviour of a clayey soil deposit in the Saga Plain, Japan, in response to groundwater fluctuation. Good agreement between the simulation and the field measurements indicates that the proposed model can be used to predict land subsidence induced by groundwater fluctuations.

In-Plane Flexible Ring Tire Model—Part 1: Modeling and Parameter Identification

2018 ◽  
Vol 46 (3) ◽  
pp. 174-219 ◽  
Author(s):  
Bin Li ◽  
Xiaobo Yang ◽  
James Yang ◽  
Yunqing Zhang ◽  
Zeyu Ma
Keyword(s):  
Static Load ◽  
Model Parameters ◽  
Tire Model ◽  
Test Results ◽  
Lumped Mass ◽  
Virtual Test ◽  
Proposed Model ◽  
Particle Swarm Method ◽  
Vehicle Dynamic Simulation ◽  
Flexible Ring

ABSTRACT The tire model is essential for accurate and efficient vehicle dynamic simulation. In this article, an in-plane flexible ring tire model is proposed, in which the tire is composed of a rigid rim, a number of discretized lumped mass belt points, and numerous massless tread blocks attached on the belt. One set of tire model parameters is identified by approaching the predicted results with ADAMS® FTire virtual test results for one particular cleat test through the particle swarm method using MATLAB®. Based on the identified parameters, the tire model is further validated by comparing the predicted results with FTire for the static load-deflection tests and other cleat tests. Finally, several important aspects regarding the proposed model are discussed.

scholarly journals Spine Examination during COVID-19 Pandemic via Video Consultation

2021 ◽  
Author(s):  
Tom Jansen ◽  
Martin Gathen ◽  
Amadeo Touet ◽  
Hans Goost ◽  
Dieter Christian Wirtz ◽  
...  
Keyword(s):  
Pain Intensity ◽  
Range Of Motion ◽  
Test Results ◽  
Risk Of Infection ◽  
Face To Face ◽  
Reliable Tool ◽  
Provocation Tests ◽  
Active Range Of Motion ◽  
Video Consultation ◽  
Good Agreement

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.

Sign in / Sign up

Export Citation Format

Share Document