On the Improvement of Calibration Coefficients for Hole-Drilling Integral Method: Part I—Analysis of Calibration Coefficients Obtained by a 3-D FEM Model

2002 ◽  
Vol 124 (2) ◽  
pp. 250-258 ◽  
Author(s):  
Jong-Ning Aoh ◽  
Chung-Sheng Wei
Keyword(s):  
Integral Method ◽  
Plate Thickness ◽  
Three Dimensional ◽  
Thin Plates ◽  
Calibration Coefficient ◽  
Hole Drilling ◽  
Three Dimensional Model ◽  
Hole Drilling Method ◽  
Wide Range ◽  
Calibration Coefficients

One of the important factors affecting the accuracy of stress values obtained from the hole-drilling method is the calibration coefficient. A three-dimensional model was established to determine the calibration coefficients for integral method. The constraint conditions and loading conditions during hole-drilling can be simulated more realistically with this method. With this new model, coefficients a¯i,j and b¯i,j could be determined within one computation procedure. The relationship between calibration coefficients and plate thickness was investigated over a wide range of plate thickness. It has been found that the calibration coefficients determined in this work may vary with thickness of plates and the thickness range for thin plates was thus well defined. The calibration coefficients can thus be extended to measure the residual stresses of either thin or thick plates. Comparison of calibration coefficients with those determined by other studies was also conducted.

On the Improvement of Calibration Coefficients for Hole-Drilling Integral Method: Part II—Experimental Validation of Calibration Coefficients

2003 ◽  
Vol 125 (2) ◽  
pp. 107-115 ◽  
Author(s):  
Jong-Ning Aoh ◽  
Chung-Sheng Wei
Keyword(s):  
Experimental Validation ◽  
Three Dimensional ◽  
Bending Test ◽  
Hole Drilling ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Fem Model ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Calibration Coefficients

Experimental validation of the calibration coefficients for integral hole-drilling method obtained from an improved three-dimensional FEM model was achieved using bending test of a cantilever beam. The experimental setup is a simple yet accurate method to validate the calibration coefficients obtained by a three-dimensional FEM model. With this experiment, we also validate the adequacy of the criterion applied for thin or thick plates in a previous work. The relieved stresses calculated from the calibration coefficients of the three-dimensional FEM model were compared with those calculated from two-dimensional model calibration coefficients. The results show that the accuracy of relieved stress calculation has been greatly improved as the calibration coefficients based on a three-dimensional model are used for integral hole-drilling method. Significant error in the residual stress measurement and calculation could be arisen if calibration coefficients for integral hole-drilling method were not chosen correctly for corresponding thin plate or thick plate cases according the results of the bending test of cantilever beam. A transitional dimensionless thickness was proposed by examining the calculated relieved stresses obtained from the calibration coefficients for different plate thickness. The probability bounds of relieved stress corresponding to both cases were also calculated to further reveal the improvement of the calibration coefficients obtained from the three-dimensional model.

scholarly journals Implicit 3D Modeling of Ore Body from Geological Boreholes Data Using Hermite Radial Basis Functions

Minerals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 443 ◽  
Author(s):  
Jinmiao Wang ◽  
Hui Zhao ◽  
Lin Bi ◽  
Liguan Wang
Keyword(s):  
Three Dimensional ◽  
Hole Drilling ◽  
Weak Continuity ◽  
Three Dimensional Model ◽  
Borehole Data ◽  
Long Distance ◽  
Hole Drilling Method ◽  
Ore Body ◽  
Radial Basis ◽  
Geometric Quality

Modeling ore body in 3D is the basis of digital intelligent mining. However, most existing three-dimensional mining software uses the contour approach that requires too much man–machine interaction and difficult partial updating. Moreover, accounting for uncertainty and low geometric quality picking is very difficult in the direct contour approach. Therefore, an implicit modeling approach to automatically build the three-dimensional model for ore body by means of spatial interpolation directly based on the geological borehole data with Hermite radial basis function (HRBF) algorithm as the core is proposed. Furthermore, in order to solve the problems of weak continuity of models due to the long-distance original boreholes as well as the boundary-point normal solution error, the densification of original borehole data with the virtual borehole as well as the calculation of point-cloud normal direction based on the adjacent hole-drilling method is proposed. The verification of two mine engineering projects and comparison with the explicit modeling results show that this approach could realize the automatic building of three-dimensional models for the ore body with high geometric quality, timely update and accurate results.

Measurement of Non-Uniform Residual Stresses Using the Hole-Drilling Method. Part II—Practical Application of the Integral Method

1988 ◽  
Vol 110 (4) ◽  
pp. 344-349 ◽  
Author(s):  
G. S. Schajer
Keyword(s):  
Integral Method ◽  
Strain Relaxation ◽  
Hole Drilling ◽  
Calibration Data ◽  
Depth Limit ◽  
Practical Applications ◽  
Hole Drilling Method ◽  
Incremental Hole Drilling ◽  
Drilling Method ◽  
Calibration Coefficients

The Integral Method for calculating non-uniform residual stress fields using strain relaxation data from the incremental hole-drilling method is examined in detail. Finite element calculations are described which evaluate the calibration coefficients required for practical applications of the method. These calibration data are tabulated for a range of hole sizes and depths. It is found that the hole drilling method is not well adapted to measuring stresses remote from the surface, and a theoretical depth limit for stress measurements of 0.5 of the mean radius of the strain gauge rosette, rm, is identified. A practical depth limit is in the range 0.3–0.4 rm.

scholarly journals Integral method coefficients for the ring-core technique to evaluate non-uniform residual stresses

2018 ◽  
Vol 53 (4) ◽  
pp. 210-224 ◽  
Author(s):  
Michele Barsanti ◽  
Marco Beghini ◽  
Ciro Santus ◽  
Alessio Benincasa ◽  
Lorenzo Bertelli
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Integral Method ◽  
Three Dimensional ◽  
Element Model ◽  
Hole Drilling ◽  
Stress Distributions ◽  
Three Dimensional Model ◽  
Small Depth ◽  
Ring Core

The ring-core technique allows for the determination of non-uniform residual stresses from the surface up to relatively higher depths as compared to the hole-drilling technique. The integral method, which is usually applied to hole-drilling, can also be used for elaborating the results of the ring-core test since these two experimental techniques share the axisymmetric geometry and the 0°–45°–90° layout of the strain gage rosette. The aim of this article is to provide accurate coefficients which can be used for evaluating the residual stress distribution by the ring-core integral method. The coefficients have been obtained by elaborating the results of a very refined plane harmonic axisymmetric finite element model and verified with an independent three-dimensional model. The coefficients for small depth steps were initially provided, and then the values for multiple integer step depths were also derived by manipulating the high-resolution coefficient matrices, thus showing how the present results can be practically used for obtaining the residual stresses according to different depth sequences, even non-uniform. This analysis also allowed the evaluation of the eccentricity effect which turned out to be negligible due to the symmetry of the problem. An applicative example was reported in which the input of the experimentally measured relaxed strains was elaborated with different depth resolutions, and the obtained residual stress distributions were compared.

Study of Surface Residual Stress by Three-Dimensional Displacement Data at a Single Point in Hole Drilling Method

1999 ◽  
Vol 122 (2) ◽  
pp. 215-220 ◽  
Author(s):  
Z. Wu ◽  
J. Lu
Keyword(s):  
Residual Stress ◽  
Single Point ◽  
Accurate Determination ◽  
Three Dimensional ◽  
Moiré Interferometry ◽  
Hole Drilling ◽  
Moire Interferometry ◽  
Blind Hole ◽  
Hole Drilling Method ◽  
Drilling Method

A method combining moire´ interferometry, Twyman–Green interferometry, and blind hole drilling method is proposed for simple and accurate determination of residual stress. The relationship between the three-dimensional surface displacements produced by introducing a blind hole and the corresponding residual stress is established by employing the Fourier expansion solution containing a set of undetermined coefficients. The coefficients are calibrated by 3D finite element method. The surface in-plane displacements Ux,Uy, and the out-of-plane displacement Uz produced by the relaxation of residual stress are measured by moire´ interferometry and Twyman–Green interferometry, respectively, after the hole-drilling procedure. The complete three-dimensional displacement data at any single point around the hole can be used for residual stress determination. The accuracy of the method is analyzed and the experimental procedure is described to determine the sign of residual stresses. As an implementation of the method, a shot peening residual stress problem is studied. [S0094-4289(00)00802-1]

scholarly journals BIM, realidad aumentada y técnicas holográficas aplicadas a la construcción = BIM, increased reality and holographic techniques applied to construction

2018 ◽  
Vol 4 (1) ◽  
pp. 27 ◽  
Author(s):  
Jaime Santamarta Martínez ◽  
Javier Mas Domínguez
Keyword(s):  
Augmented Reality ◽  
New Technologies ◽  
Three Dimensional ◽  
Pilot Project ◽  
Information Modeling ◽  
Three Dimensional Model ◽  
Modeling Methodology ◽  
Wide Range ◽  
Building Information ◽  
Nuevas Tecnologías

ResumenLa metodología BIM (Building Information Modelling), ampliamente implantada en el sector de la edificación y de la arquitectura, ha transformado la manera de desarrollar tanto los proyectos como las obras de construcción. Si bien la esencia de esta metodología se basa en la generación de un modelo tridimensional, la visualización de éste a través de dispositivos bidimensionales hace que la experiencia e interacción con el modelo no sea plena. Es por ello que la aparición en el mercado de nuevas tecnologías como la realidad virtual y la realidad aumentada, abren un amplio abanico de posibilidades ligadas al sector de la construcción. En este sentido, en Acciona Ingeniería se ha desarrollado un proyecto piloto en colaboración con Trimble y Microsoft donde a partir de un modelo BIM se ha creado una realidad aumentada basada en hologramas, que permitan recrear una simulación aplicada a la construcciónAbstractThe BIM (Building Information Modeling) methodology, widely implemented in the building and architecture sector, has transformed the way to develop both projects and construction works. Although the essence of this methodology is based on the generation of a three-dimensional model, the visualization of it through two-dimensional devices means that the experience and interaction with the model is not complete. That is why the appearance in the market of new technologies such as virtual reality and augmented reality, open a wide range of possibilities linked to the construction sector. In this sense, Acciona Engineering has developed a pilot project in collaboration with Trimble and Microsoft where, based on a BIM model, an augmented reality based on holograms has been created, allowing to recreate a simulation applied to construction

A Tubular Cross-Flow Filtration Module Based on Chaotic Advection

2015 ◽  
Author(s):  
T. G. Kang ◽  
K. T. Park ◽  
S. U. Kim
Keyword(s):  
Turbulent Flows ◽  
Three Dimensional ◽  
Cross Flow ◽  
Operating Conditions ◽  
Membrane Module ◽  
Chaotic Advection ◽  
Thin Plates ◽  
Tubular Membrane ◽  
Cross Flow Filtration ◽  
Wide Range

We propose a tubular membrane module with embedded three-dimensional structures which is efficient in a wide range of operating conditions (covering both laminar and turbulent flows). Thin plates with barriers are inserted periodically in the circular channel geometry, leading to chaotic advection in a spatially periodic channel flow. Using a numerical scheme combining a particle-tracking and the finite element method, the insert geometry is optimized. The performance of the newly proposed membrane module is assessed by experiments. The membrane module with embedded inserts is found to be better in performance than an ordinary tubular membrane module.

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