scholarly journals Developing 1D MM of Axisymmetric Transient Quenched Chromium Steel to Determine LHP

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Abdlmanam S. A. Elmaryami ◽  
Badrul Omar
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Chromium Steel ◽  
Temperature History ◽  
Finite Element Software ◽  
Steel Bar ◽  
History Of ◽  
Quenched Steel ◽  
The Impact ◽  
The Mathematical Model

The modelling of an axisymmetric industrial quenched chromium steel bar AISI-SAE 8650H based on finite element method has been produced to investigate the impact of process history on metallurgical and material properties. Mathematical modelling of 1-dimensional line (radius) element axisymmetric model has been adopted to predict temperature history and consequently the hardness of the quenched steel bar at any point (node). The lowest hardness point (LHP) is determined. In this paper hardness in specimen points was calculated by the conversion of calculated characteristic cooling time for phase transformation t8/5 to hardness. The model can be employed as a guideline to design cooling approach to achieve desired microstructure and mechanical properties such as hardness. The developed mathematical model is converted to a computer program. This program can be used independently or incorporated into a temperature history calculator to continuously calculate and display temperature history of the industrial quenched steel bar and thereby calculate LHP. The developed program from the mathematical model has been verified and validated by comparing its hardness results with commercial finite element software results.

Developing 1-D MM of Transient Industrial Quenched Chromium Steel-5147H to Study the Effect of Radius on Temperature History

2013 ◽  
Vol 711 ◽  
pp. 115-127
Author(s):  
Badrul Omar ◽  
Abdlmanam S.A. Elmaryami
Keyword(s):  
Mechanical Properties ◽  
Mathematical Model ◽  
Finite Element ◽  
Chromium Steel ◽  
Temperature History ◽  
Finite Element Software ◽  
Steel Bar ◽  
Proposed Model ◽  
History Of ◽  
The Impact

Mathematical modeling of an axisymmetric transient industrial quenched chromium steel bar AISI-SAE 5147H, water cooled based on finite element method has been produced to investigate the impact of process history on metallurgical and material properties. Mathematical modelling of 1-D line (radius) element axisymmetric model has been adopted to predict temperature history of the quenched chromium steel bar at any point (node). The temperature history of four different radii cylindrical geometry chromium steel 5147H is determined. The temperature history needs to be properly understood in order to efficiently produce high quality components. The model can be employed as a guideline to design cooling approach to achieve desired microstructure and mechanical properties such as hardness. The developed mathematical model converted to a computer program. This program can be used independently or incorporated into a temperature history calculator to continuously calculate and display temperature history of the industrial quenched chromium steel bar and thereby calculate the mechanical properties. The developed program from the mathematical model has been verified and validated by comparing its temperature simulation results with commercial finite element software results. The comparison indicates reliability of the proposed model.

scholarly journals Acoustic Velocity Correcting Method for the Tilted Acoustic Tube in Testing of Pile by Ultrasonic Transmission

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Yongqiang Cui ◽  
Zhitao Ma ◽  
Yachao Yang ◽  
Daifu Song
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Finite Element ◽  
Acoustic Signal ◽  
Acoustic Velocity ◽  
Normal Value ◽  
Finite Element Software ◽  
Modified Method ◽  
The Mathematical Model ◽  
Depth Curve

The finite element software ABAQUS was used to simulate the detection of piles by ultrasonic transmission. The influence of the tilted acoustic tube on the testing results of the pile was analyzed. The results showed that, when the pile was complete, the velocity of the sound-depth curve of the received signal was inclined to one side due to the inclination of the acoustic tube and the velocity of the sound seriously deviated from the normal value; when there was a defect in the pile, the signal of the defect was not obvious due to the tilt of the acoustic tube, which was easy to miss or misjudge the defects of the pile. To solve the problem of the inclined acoustic tube, the mathematical model of the position relation of the acoustic tube was established, and the method for correcting the velocity of the sound based on the angle of the acoustic tube was derived. Numerical simulation and engineering examples were used to verify the modified method; the verification showed that the corrected acoustic signal could accurately determine the defects and their positions in the pile, and this method effectively reduced the influence of the tilted acoustic tube on the detection signal, which was beneficial to improve the accuracy of the testing for the pile.

scholarly journals Numerical Study of Being Forced Leather Cap Type Pig in Straight Gas Pipeline

2016 ◽  
Vol 10 (1) ◽  
pp. 141-148
Author(s):  
Liqiong Chen ◽  
Yunyun Li ◽  
Xiaoxiao Chen ◽  
Yilan Zhan ◽  
Meijuan Dang
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Numerical Study ◽  
Geometric Model ◽  
Gas Pipeline ◽  
Average Force ◽  
Oil Pipeline ◽  
Finite Element Software ◽  
Operation Rules ◽  
The Mathematical Model

The research on pipeline pigging technology is significant for the operation and management of pipeline. Domestic and foreign scholars usually research the operation rules of pigging in oil pipeline. There are few studies about gas pipeline pigging running because of running rate. The author established the force calculating model and corresponding numerical methods of leather cap type pig in gas pipeline. The model is based on geometric model of oil pipeline pigging. Combining pigging operation parameters with records in September 2013 and February 2014 at Bei Neihuan, the thesis used mathematical method and finite element software respectively to verify the mathematical model. The mathematical results described the average force of cup. The results indicated that the reason of the breaking of the cup is the force, instead of the cup material, temperament extrinsic reasons, etc. The force is larger than the tensile strength of the cup. The results of ANSYS finite element software simulation described the force of different parts of the cup. It is found that the force exceeding of the cup anti-pull force strength in the upper and lower sides of the cup is larger. Both results showed that using the mathematical model can quickly calculate cup pigging force conditions and determine the cause of damage to the cup. It can improve the efficiency of pigging.

scholarly journals Utilization of Numerical Techniques to Predict the Thermal Behavior of Wood Column Subjected to Fire. Part A: Using Finite Element Methods to Develop Mathematical Model for Wood Column

2006 ◽  
Vol 306-308 ◽  
pp. 577-582
Author(s):  
Mohamed ElShayeb ◽  
Abdul Rashid Ab Malik ◽  
Fazril Ideris ◽  
Zolman Hari ◽  
Norhaida Ab Razak ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Thermal Behavior ◽  
Temperature History ◽  
Two Dimensional ◽  
Numerical Techniques ◽  
Materials Properties ◽  
The Mathematical Model ◽  
Develop Mathematical Model ◽  
Wood Columns

The mathematical model to predict the temperature history for wood column is needed in order to determine its fire resistance when exposed to fire. In this paper, an intelligent methodology called Finite Element Method (FEM) of performing analysis for the square and circular wood columns by virtually or artificially developing a temperature history mathematical model. Numerical simulation model has been developed for the wood column by using two-dimensional mathematical model. The two-dimensional mathematical model was developed by using Galerkin’s Weighted Residual technique. This model focuses on the regional material of the wood column for describing its thermal behavior. When the temperature history in a column and relevant materials properties are known, the strength of the column can be calculated at any time during fire. Therefore, the development of the temperature history mathematical model is a must before any further study to be carried out for the wood columns. The flow of convection will result in minimal increase in the rate of heat energy reaching the column core. The analysis shows that the temperature of the column increases with respect to the duration of exposure to fire.

scholarly journals The Impact of Elongation on Change in Electrical Resistance of Electrically Conductive Yarns Woven into Fabric

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3390
Author(s):  
Željko Knezić ◽  
Željko Penava ◽  
Diana Šimić Penava ◽  
Dubravko Rogale
Keyword(s):  
Mathematical Model ◽  
Electrical Resistance ◽  
Electrically Conductive ◽  
Textile Materials ◽  
Measurement Results ◽  
Conductive Yarns ◽  
Yarn Count ◽  
As Relationship ◽  
The Impact ◽  
The Mathematical Model

Electrically conductive yarns (ECYs) are gaining increasing applications in woven textile materials, especially in woven sensors suitable for incorporation into clothing. In this paper, the effect of the yarn count of ECYs woven into fabric on values of electrical resistance is analyzed. We also observe how the direction of action of elongation force, considering the position of the woven ECY, effects the change in the electrical resistance of the electrically conductive fabric. The measurements were performed on nine different samples of fabric in a plain weave, into which were woven ECYs with three different yarn counts and three different directions. Relationship curves between values of elongation forces and elongation to break, as well as relationship curves between values of electrical resistance of fabrics with ECYs and elongation, were experimentally obtained. An analytical mathematical model was also established, and analysis was conducted, which determined the models of function of connection between force and elongation, and between electrical resistance and elongation. The connection between the measurement results and the mathematical model was confirmed. The connection between the mathematical model and the experimental results enables the design of ECY properties in woven materials, especially textile force and elongation sensors.

The Impact Analysis of Revolute Pair Clearance to the End Pose Accuracy of Welding Robot

2015 ◽  
Vol 778 ◽  
pp. 259-263
Author(s):  
Fa Jun Zhang ◽  
Lin Zi Li ◽  
Hui Lin ◽  
Yin Lin Pu ◽  
Zhu Xin
Keyword(s):  
Mathematical Model ◽  
Impact Analysis ◽  
Joint Clearance ◽  
Welding Robot ◽  
Movement Characteristic ◽  
Movement Stability ◽  
Simulation Results ◽  
The Impact ◽  
The Mathematical Model ◽  
Welding Position

Various uncertain factors affect the movement of the welding robot, thus welding gun tend to deviate from the theory of welding position which reduces the welding accuracy, of which the revolute pair clearance have an greater effect on the movement of the welding robot. In order to study the influence of revolute pair clearance to the end pose accuracy of welding robot, the mathematical model of revolute pair clearance was established, and the software SolidWorks was used for establishing the welding robot model, making simulations of the mechanical arm with joint clearance and no joint clearance. At last, the movement characteristic of the hinge shaft is attained. The simulation results showed that the shaft velocity and displacement of mechanical arm with joint clearance has a certain degree of fluctuation, which affecting the end pose accuracy of welding robot , and reducing the movement stability and the welding accuracy of welding robot.

Enhancement the Solar Still Performance Using Chimney Exhaust Gases

2021 ◽  
Author(s):  
Hamdy Hassan
Keyword(s):  
Mathematical Model ◽  
Theoretical Study ◽  
Saline Water ◽  
Kutta Method ◽  
Solar Still ◽  
Climate Conditions ◽  
Exhaust Gases ◽  
Runge Kutta Method ◽  
The Impact ◽  
The Mathematical Model

Abstract In this paper, a theoretical study is presented on enhancement of the solar still performance by using the exhaust gases passing inside a chimney under the still basin. The impact of the exhaust gases temperature on the solar still temperature, productivity, and efficiency are considered. The performance of solar still with chimney is compared with that of conventional solar still. The study is carried out under the hot and climate conditions of Upper Egypt. A complete transient mathematical model of the physical model including the solar still regions temperatures, productivity, and heat transfer between the solar still and the exhaust gases are constructed. The mathematical model is solved numerically by using fourth-order Runge-Kutta method and is programmed by using MATLAB. The mathematical model is validated using an experimental work. The results show that the solar still saline water temperature increases and productivity with using and rising the exhaust gases. Furthermore, the impact of using exhaust gases on the still performance in winter is greater than in summer. using chimney exhaust gases at 75 °C and 125 °C enhances the daily freshwater yield of the conventional still by more than three times and about six times in winter, respectively, and about two and half times and more than three times in summer, respectively.

scholarly journals Numerical simulation of blanking process

2018 ◽  
Vol 157 ◽  
pp. 02038
Author(s):  
Peter Pecháč ◽  
Milan Sága
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Steel Sheet ◽  
Plastic Material ◽  
Material Model ◽  
Rolled Steel ◽  
Finite Element Software ◽  
History Of ◽  
Cold Rolled ◽  
Blanking Process

This paper presents numerical simulation of blanking process for cold-rolled steel sheet metal. The problem was modeled using axial symmetry in commercial finite element software ADINA. Data obtained by experimental measurement were used to create multi-linear plastic material model for simulation. History of blanking force vs. tool displacement was obtained.

scholarly journals Collapse Analysis of a Transmission Tower-Line System Induced by Ice Shedding

2021 ◽  
Vol 9 ◽  
Author(s):  
Jiaxiang Li ◽  
Biao Wang ◽  
Jian Sun ◽  
Shuhong Wang ◽  
Xiaohong Zhang ◽  
...  
Keyword(s):  
Finite Element ◽  
Transmission Lines ◽  
Progressive Collapse ◽  
Element Model ◽  
Transmission Tower ◽  
Line System ◽  
Finite Element Software ◽  
Transmission Towers ◽  
Ice Shedding ◽  
The Impact

Ice shedding causes transmission lines to vibrate violently, which induces a sharp increase in the longitudinal unbalanced tension of the lines, even resulting in the progressive collapse of transmission towers in serious cases, which is a common ice-based disaster for transmission tower-line systems. Based on the actual engineering characteristics of a 500 kV transmission line taken as the research object, a finite element model of a two-tower, three-line system is established by commercial ANSYS finite element software. In the modeling process, the uniform mode method is used to introduce the initial defects, and the collapse caused by ice shedding and its influencing parameters are systematically studied. The results show that the higher the ice-shedding height is, the greater the threat of ice shedding to the system; furthermore, the greater the span is, the shorter the insulator length and the greater the dynamic response of the line; the impact of ice shedding should be considered in the design of transmission towers.

scholarly journals NECESSITY TO IMPROVE THE MATHEMATICAL MODEL OF FREIGHT CARS TO STUDY CASES OF ITS DERAILMENTS

2020 ◽  
pp. 442-451
Author(s):  
А.V. Batig ◽  
A. Ya. Kuzyshyn
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Computer Experiment ◽  
Rolling Stock ◽  
Software Systems ◽  
Freight Car ◽  
The Stability ◽  
The Many ◽  
The Impact ◽  
The Mathematical Model

One of the most important problems that pose a serious threat to the functioning of railways is the problem of freight cars derailment. However, according to statistics, the number of cases of the derailments of freight cars in trains annually grows. Тo prevent such cases, the necessary preventive measures are developed, and to study the causes of their occurrence, a significant number of mathematical models, programs and software systems created by leading domestic and foreign scientists. Studies of such mathematical models by the authors of this work have led to the conclusion that they are not sufficiently detailed to the extent that it is necessary for analyze the reasons of its derailment. At the same time, an analysis of the causes of the rolling stock derailments on the railways of Ukraine over the past five years showed that in about 20 % of cases they are obvious, and in 7 % of cases they are not obvious and implicitly expressed. The study of such cases of rolling stock derailment during an official investigation by the railway and during forensic railway transport expertises requires the use of an improved mathematical model of a freight car, which would allow a quantitative assessment of the impact of its parameters and rail track on the conditions of railway accidents. Therefore, taking into account the main reasons that caused the occurrence of such railroad accidents over the last five years on the railways of Ukraine, the article selected the main directions for improving the mathematical model of a freight car, allowing to cover all the many factors (explicit and hidden) and identify the most significant ones regarding the circumstances of the derailment rolling stock off the track, established on the basis of a computer experiment. It is proposed in the mathematical model of a freight car to take into account the guiding force, the value of which is one of the main indicators of the stability of the rolling stock. The authors of the article noted that not taking into account the influence of the guiding forces on the dynamics of the freight car can lead to an erroneous determination of the reasons for the rolling stock derailment or even to the impossibility of establishing them.

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