scholarly journals MATHEMATICAL MODEL OF SURFACE PROFILE ARITHMETIC MEAN DEVIATION FORMATION AT SHOT PEEN FORMING

2018 ◽  
Vol 22 (2) ◽  
pp. 26-33 ◽  
Author(s):  
Vladimir Koltsov ◽  
◽  
Vinh Le Tri ◽  
Daria Starodubtseva ◽  
◽  
...  
Keyword(s):  
Mathematical Model ◽  
Surface Profile ◽  
Arithmetic Mean ◽  
Mean Deviation ◽  
Peen Forming

scholarly journals Disk height ratio impact in combined tool upon roughness of ground surface

2021 ◽  
Vol 2021 (5) ◽  
pp. 14-18
Author(s):  
Vladimir Gusev ◽  
Elizaveta Sobol'kova
Keyword(s):  
Surface Profile ◽  
Ground Surface ◽  
Arithmetic Mean ◽  
Mean Deviation ◽  
Height Ratio ◽  
Minimum Value ◽  
Fine Grain ◽  
The Impact ◽  
Disk Height

The impact of the height ratio of fine-grain abrasive disks and coarse grinding ones included in a combined tool upon roughness of the surface ground is considered. There are drawn dependence diagrams of the arithmetic mean deviation of the ground surface profile in the function of independent factors of the process. On the basis of the multi-factor experiment carried out there is defined a ratio of heights of grinding disks mentioned ensuring a minimum value of the micro-geometry of the surface worked.

scholarly journals A Simple Model to Predict Machined Depth and Surface Profile for Picosecond Laser Surface Texturing

2018 ◽  
Vol 8 (11) ◽  
pp. 2111 ◽  
Author(s):  
Jieyu Xian ◽  
Xingsheng Wang ◽  
Xiuqing Fu ◽  
Zhengwei Zhang ◽  
Lu Liu ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Surface Texturing ◽  
Surface Profile ◽  
Picosecond Laser ◽  
Scanning Speed ◽  
Laser Surface ◽  
Laser Surface Texturing ◽  
Micro Channels ◽  
Surface Profiles ◽  
Simulation Parameters

A simple mathematical model was developed to predict the machined depth and surface profile in laser surface texturing of micro-channels using a picosecond laser. Fabrication of micro-craters with pulse trains of different numbers was initially performed. Two baseline values from the created micro-craters were used to calculate the estimated simulation parameters. Thereafter, the depths and profiles with various scanning speeds or adjacent intervals were simulated using the developed model and calculated parameters. Corresponding experiments were conducted to validate the developed mathematical model. An excellent agreement was obtained for the predicted and experimental depths and surface profiles. The machined depth decreased with the increase of scanning speed or adjacent interval.

Prestressing Steel Reinforcement Wire Bond Index Number

2013 ◽  
Author(s):  
Mark Haynes ◽  
Chih-Hang John Wu ◽  
B. Terry Beck ◽  
Naga Narendra B. Bodapati ◽  
Robert J. Peterman
Keyword(s):  
Mathematical Model ◽  
Bond Strength ◽  
Surface Profile ◽  
Steel Reinforcement ◽  
Index Number ◽  
Transfer Length ◽  
Bond Index ◽  
Prestressing Steel ◽  
Geometrical Features ◽  
The Wire

The purpose of this research project is to develop a mathematical model that predicts the bond strength of a prestressing steel reinforcement wire given the known geometrical features of the wire. The geometrical features of the reinforcement wire were measured by a precision non-contact profilometer. With this mathematical model, prestressing reinforcement wires can now be analyzed for their bond strength without destructive testing. This mathematical model has the potential to serve as a quality control assessment in reinforcement wire production. In addition this mathematical model will provide insight into which reinforcement wires provide the greatest bond strength and which combinations of geometrical features of the reinforcement wire are responsible for providing the bond strength. A precision non-contact profilometer has been developed to measure the important geometrical features of the reinforcement wire. The profilometer is capable of sub-micron resolution measurements to provide an extremely high quality three-dimensional rendering of the reinforcement wire surface profile. From this detailed profile data it is then possible to extract all of the relevant geometrical features of the reinforcement wire. A mathematical model has been created by testing a variety of different reinforcement wires available in the market. By correlating the transfer length of concrete prisms made with the reinforcement wires to various geometrical features, several different levels of mathematical correlation complexity have been investigated. The current empirical correlation models under development are first order and combine three to four unique geometrical features of the reinforcement wire which then act as predictors of the concrete prism transfer length. The resulting mathematical model relating the wire geometrical features to transfer length is referred to as the Bond Index Number (BIN). The BIN is shown to provide a numerical measure of the bond strength of prestressing steel reinforcement wire, without the need for performing destructive tests with the reinforcement wire.

A Simple Mathematical Model of Intradialytic Sodium Kinetics: “in vivo” Validation During Hemodialysis with Constant or Variable Sodium

1996 ◽  
Vol 19 (7) ◽  
pp. 393-403 ◽  
Author(s):  
M. Ursino ◽  
L. Colì ◽  
G. La Manna ◽  
M. Grilli Cicilioni ◽  
V. Dalmastri ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Measurement Errors ◽  
Sodium Concentration ◽  
Mean Deviation ◽  
Algebraic Characterization ◽  
Dialysis Session ◽  
Simple Mathematical Model ◽  
Model Predictions ◽  
Dialysate Sodium

A simple mathematical model of the intradialytic relationship between natraemia and dialysate sodium concentration is presented. The model includes a bicompartmental description of sodium, urea and fluid kinetics and an algebraic characterization of diffusive/convective mass-transfer across the dialysis membrane. Its ability to provide realistic responses has been validated comparing model predictions by a priori parameter tuning against quantities measured during in vivo sessions with both constant and variable dialysate sodium concentration. A quantitative analysis of model predictions indicates that the mean deviation between data calculated by the model and those measured in vivo is 1.32 mEq/l for sodium and 0.76 mmol/l for urea, values which do not greatly exceed the measurement errors of current instruments. The model's predictive capacity thus proves reliable. The ability of the model to calculate the amount of sodium removed and the time course of intra-extracellular volumes during the dialysis session makes it possible to forecast the patient's clinical tolerance to a given sodium dialysate concentration.

Surface Topography Characteristic and Statistical Characteristic of 1Cr18Ni9Ti Polished by Electrochemical Polishing

2009 ◽  
Vol 626-627 ◽  
pp. 309-314 ◽  
Author(s):  
Gui Bing Pang ◽  
D. Chen ◽  
Fei Teng ◽  
Ze Fei Wei ◽  
Wen Ji Xu
Keyword(s):  
Surface Quality ◽  
Statistical Characteristic ◽  
Surface Profile ◽  
Material Object ◽  
Mean Deviation ◽  
Initial Surface ◽  
Electrochemical Polishing ◽  
Surface Geometry ◽  
Shape Characteristic ◽  
Mean Width

The surface quality of components has the important influence on the components’ operational performance, characteristic of the geometry topography and statistical Characteristic is the important aspect of the surface quality. This study takes the arithmetic mean deviation of the assessed profile (Ra) to reflect the altitude characteristic of the surface profile, takes the mean width of the profile elements (Sm) to reflect the width characteristic of the surface profile, takes the material ratio of the profile (tp) to reflect the shape characteristic of the surface profile and takes the altitude density function φ(z) and autocorrelation function R(l) to reflect the statistical characteristic. Four groups of experiments are carried out in which 1Cr18Ni9Ti is taken as the material object of the test piece and test pieces with different initial surface roughness are polished. By experiment, the changing rules of the value of Ra, Sm, tp, φ(z) and R(l) after different polishing time are obtained. By analyzing the changing rules of Ra, Sm, tp, φ(z) and R(l), the influence of the Electrochemical Polishing (ECP) process on the surface geometry and statistical characteristic is obtained.

scholarly journals Accuracy of Cycling Power Meters against a Mathematical Model of Treadmill Cycling

2017 ◽  
Vol 38 (06) ◽  
pp. 456-461 ◽  
Author(s):  
Thomas Maier ◽  
Lucas Schmid ◽  
Beat Müller ◽  
Thomas Steiner ◽  
Jon Wehrlin
Keyword(s):  
Mathematical Model ◽  
Coefficient Of Variation ◽  
Mean Deviation ◽  
First Principle ◽  
Power Meter ◽  
Coefficients Of Variation ◽  
The Mean

AbstractThe aim of this study was to compare the accuracy among a high number of current mobile cycling power meters used by elite and recreational cyclists against a first principle-based mathematical model of treadmill cycling. 54 power meters from 9 manufacturers used by 32 cyclists were calibrated. While the cyclist coasted downhill on a motorised treadmill, a back-pulling system was adjusted to counter the downhill force. The system was then loaded 3 times with 4 different masses while the cyclist pedalled to keep his position. The mean deviation (trueness) to the model and coefficient of variation (precision) were analysed. The mean deviations of the power meters were –0.9±3.2% (mean±SD) with 6 power meters deviating by more than±5%. The coefficients of variation of the power meters were 1.2±0.9% (mean±SD), with Stages varying more than SRM (p<0.001) and PowerTap (p<0.001). In conclusion, current power meters used by elite and recreational cyclists vary considerably in their trueness; precision is generally high but differs between manufacturers. Calibrating and adjusting the trueness of every power meter against a first principle-based reference is advised for accurate measurements.

scholarly journals Formation of the surface roughness during grinding with flap wheels after shot peening

2018 ◽  
Vol 224 ◽  
pp. 01070
Author(s):  
Darya Starodubtseva ◽  
Vinh Le Tri ◽  
Vladimir Koltsov
Keyword(s):  
Surface Roughness ◽  
Shot Peening ◽  
Three Dimensional ◽  
Mean Deviation ◽  
Optical Scanning ◽  
Peen Forming ◽  
Mandatory Requirement ◽  
Part Surface ◽  
Surface Microgeometry ◽  
Different Diameters

Shot peening is widely used in forming long panels and sheaths. Due to impact by shot on the processed surface, a specific microgeometry is formed, the characteristic feature of this microgeometry are the numerous dimples as the traces of shot impact with different diameters and depths. A presence of these dimples causes deterioration of the surface roughness parameters. Therefore, after shot peening the mandatory requirement is the implementation of surface grinding with flap wheels for partial removal of the dimples. The size of the assigned allowance for grinding depends on the quality requirements of the part surface. At the same time, the depths of the remaining dimples are determined by the part surface roughness requirements. After grinding, the new surface microgeometry is formed, as a combination of micro-roughness from previous types of processing and the remained dimples in result of shot peening. In this work the microgeometry formation of surface layer of the samples after shot peen forming and subsequent grinding with flap wheels was analysed. The parameters of surface roughness were measured by the method of three-dimensional optical scanning. In the measurement result, the mathematical model of the surface micro-profile formation was formulated, the analytical dependences of the position of the center plane and the arithmetic mean deviation of profile were obtained.

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