Three-dimensional filtering of engineering surfaces using a least squares non-parametric B-spline surface

1997 ◽  
Vol 211 (7) ◽  
pp. 557-564 ◽  
Author(s):  
J Tholath ◽  
V Radhakrishnan
Keyword(s):  
Surface Roughness ◽  
Least Squares ◽  
Three Dimensional ◽  
B Spline ◽  
Spline Surface ◽  
Filtering Procedure ◽  
Dimensional Surface ◽  
Non Parametric

With the advent of cheap and powerful computers, three-dimensional evaluation of surfaces is possible. The three-dimensional surface requires a filtering procedure for waviness separation. This paper deals with the waviness plane construction through a least squares non-parametric B-spline surface. Roughness values obtained by two-, two-and-a-half- and three-dimensional evaluations of typical surfaces are also given.

A B-Spline Least-Squares Surface-Fitting Method for Articular Surfaces of Diarthrodial Joints

1993 ◽  
Vol 115 (4A) ◽  
pp. 366-373 ◽  
Author(s):  
G. A. Ateshian
Keyword(s):  
Least Squares ◽  
Articular Surface ◽  
Three Dimensional ◽  
Surface Fitting ◽  
B Spline ◽  
Spline Surface ◽  
Articular Surfaces ◽  
Diarthrodial Joint ◽  
Surface Data ◽  
Fitting Method

The B-spline least-squares surface-fitting method is employed to create geometric models of diarthrodial joint articular surfaces. This method provides a smooth higher-order surface approximation from experimental three-dimensional surface data that have been obtained with any suitable measurement technique. Akima’s method for surface interpolation is used to provide complete support to the B-spline surface. The surface-fitting method is successfully tested on a known analytical surface, and is applied to the human distal femur. Applications to other articular surfaces are also shown. Results show that this method is precise, highly flexible, and can be successfully applied to a large variety of articular surface shapes.

Enhancement of Heat Transfer Performance in Nuclear Fuel Rod Using Nanofluids and Surface Roughness Technique

2015 ◽  
Author(s):  
Kang Liu ◽  
Titan C. Paul ◽  
Leo A. Carrilho ◽  
Jamil A. Khan
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Nuclear Fuel ◽  
Three Dimensional ◽  
Pressurized Water ◽  
Bulk Fluid ◽  
Fuel Rod ◽  
Dimensional Surface

The experimental investigations were carried out of a pressurized water nuclear reactor (PWR) with enhanced surface using different concentration (0.5 and 2.0 vol%) of ZnO/DI-water based nanofluids as a coolant. The experimental setup consisted of a flow loop with a nuclear fuel rod section that was heated by electrical current. The fuel rod surfaces were termed as two-dimensional surface roughness (square transverse ribbed surface) and three-dimensional surface roughness (diamond shaped blocks). The variation in temperature of nuclear fuel rod was measured along the length of a specified section. Heat transfer coefficient was calculated by measuring heat flux and temperature differences between surface and bulk fluid. The experimental results of nanofluids were compared with the coolant as a DI-water data. The maximum heat transfer coefficient enhancement was achieved 33% at Re = 1.15 × 105 for fuel rod with three-dimensional surface roughness using 2.0 vol% nanofluids compared to DI-water.

scholarly journals Multiscale three-dimensional surface reconstruction and surface roughness of porcine left anterior descending coronary arteries

2019 ◽  
Vol 6 (9) ◽  
pp. 190915 ◽  
Author(s):  
Hanna E. Burton ◽  
Rachael Cullinan ◽  
Kyle Jiang ◽  
Daniel M. Espino
Keyword(s):  
Surface Roughness ◽  
Coronary Arteries ◽  
Medical Devices ◽  
Ex Vivo ◽  
Three Dimensional ◽  
Force Microscopy ◽  
Optical Scanning ◽  
Atomic Force ◽  
Reconstructed Surface ◽  
Dimensional Surface

The aim of this study was to investigate the multiscale surface roughness characteristics of coronary arteries, to aid in the development of novel biomaterials and bioinspired medical devices. Porcine left anterior descending coronary arteries were dissected ex vivo , and specimens were chemically fixed and dehydrated for testing. Surface roughness was calculated from three-dimensional reconstructed surface images obtained by optical, scanning electron and atomic force microscopy, ranging in magnification from 10× to 5500×. Circumferential surface roughness decreased with magnification, and microscopy type was found to influence surface roughness values. Longitudinal surface roughness was not affected by magnification or microscopy types within the parameters of this study. This study found that coronary arteries exhibit multiscale characteristics. It also highlights the importance of ensuring consistent microscopy parameters to provide comparable surface roughness values.

Measuring and Quantifying the Surface-Roughness Anisotropy of Modeled and Industrially Produced Surfaces

2005 ◽  
Vol 6-8 ◽  
pp. 573-582 ◽  
Author(s):  
C.M. Wichern ◽  
W. Rasp
Keyword(s):  
Surface Roughness ◽  
Rolling Direction ◽  
Three Dimensional ◽  
Roughness Parameter ◽  
Orientation Angle ◽  
Textured Surface ◽  
Angular Orientation ◽  
Textured Surfaces ◽  
Average Roughness ◽  
Dimensional Surface

‘Three-dimensional surface profilometry’ when used for analysis and product specification reports roughness parameters that provide an average surface description over a relatively large area. Many commercial sheet steels are produced with special textured surfaces for tribological benefits or appearance benefits. These surfaces, as well as others, may demonstrate high levels of roughness anisotropy that is not quantifiable by simple three dimensional surface parameters. This anisotropy can play an important role in the surface appearance of the finished product and in the tribological behaviour during forming. The current work presents a method for quantifying surface-roughness features as a function of angular orientation with respect to rolling direction. The measurement methodology was applied to several model surfaces and one industrially produced electron-beam textured-surface (EBT). This methodology extracts multiple surface-height profiles of the same angular orientation from a single surface and calculates an average roughness parameter for the orientation angle based on the multiple profiles. Particularly interesting results were the large number of profiles necessary to obtain repeatable values for the roughness variation with respect to direction and the strong influence of surface feature size on the repeatability of said results. These results indicate that care must be taken when using a single extracted profile to represent a ‘three-dimensional’ surface.

Evaluation and ANN-Based Prediction on Functional Parameters of Surface Roughness in Precision Grinding of Cast Iron

2014 ◽  
Vol 1017 ◽  
pp. 166-171
Author(s):  
Bin Zhao ◽  
Song Zhang ◽  
Jian Feng Li
Keyword(s):  
Surface Roughness ◽  
Cast Iron ◽  
Three Dimensional ◽  
Ann Model ◽  
Linear Speed ◽  
Functional Parameters ◽  
Grinding Parameters ◽  
Ann Models ◽  
Artificial Neural Network Ann ◽  
Dimensional Surface

Three-dimensional surface roughness parameters are widely applied to characterize frictional and lubricating properties, corrosion resistance, fatigue strength of surfaces. Among them, the functional parameters of surface roughness, such as Sbi, Sci, and Svi, are used to evaluate bearing and fluid retention properties of surfaces. In this study, the effects of grinding parameters, including wheel linear speed (Vs), workpiece linear speed (Vw), grinding depth (ap), longitudinal feed rate (fa), and dressing rate (F), on functional parameters were studied in grinding of cast iron. An artificial neural network (ANN) model was developed for predicting the functional parameters of three-dimensional surface roughness. The inputs of the ANN models were grinding parameters (Vs, Vw, ap, fa, F), and the output parameters of the models were functional parameters of surface roughness (Sbi, Sci, Svi). With small errors (e.g MSE = 0.09%, 0.61%, and 0.0014%. ), the ANN-based models are considered sufficiently accurate to predict functional parameters of surface roughness in grinding of cast iron.

Modeling Effects of Material Properties and Three-Dimensional Surface Roughness on Thermal Barrier Coatings

2000 ◽  
Vol 645 ◽  
Author(s):  
Michael L. Glynn ◽  
K.T. Ramesh ◽  
P.K. Wright ◽  
K.J. Hemker
Keyword(s):  
Surface Roughness ◽  
Residual Stresses ◽  
Thermal Barrier Coatings ◽  
Material Properties ◽  
Bond Coat ◽  
Coefficient Of Thermal Expansion ◽  
Three Dimensional ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Dimensional Surface

ABSTRACTThermal barrier coatings (TBCs) are known to spall as a result of the residual stresses that develop during thermal cycling. TBC's are multi-layered coatings comprised of a metallic bond coat, thermally grown oxide and the ceramic top coat, all on top of a Ni-base superalloy substrate. The development of residual stresses is related to the generation of thermal, elastic and plastic strains in each of the layers. The focus of the current study is the development of a finite element analysis (FEA) that will model the development of residual stresses in these layers. Both interfacial roughness and material parameters (e.g., modulus of elasticity, coefficient of thermal expansion and stress relaxation of the bond coat) play a significant role in the development of residual stresses. The FEA developed in this work incorporates both of these effects and will be used to study the consequence of interface roughness, as measured in SEM micrographs, and material properties, that are being measured in a parallel project, on the development of these stresses. In this paper, the effect of an idealized three-dimensional surface roughness is compared to residual stresses resulting from a grooved surface formed by revolving a sinusoidal wave about an axis of symmetry. It is shown that cylindrical and flat button models give similar results, while the 3-D model results in stresses that are significantly larger than the stresses predicted in 2-D.

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