scholarly journals Design and Analysis of a Drilling Fixture

2020 ◽  
pp. 56-60
Keyword(s):  
Element Analysis ◽  
Accuracy And Precision ◽  
Manufacturing Sectors ◽  
Manual Handling ◽  
Displacement Theory ◽  
Solid Works ◽  
Critical Components ◽  
Improved Accuracy ◽  
External Loads ◽  
Conventional Drilling

The Automation field is rapidly taking over the production and manufacturing sectors because of its heightened performance with improved accuracy and precision. Therefore, it is essential to understand the application and the significance of the involvement of automation in conventional drilling machines. The CAD geometry of the project is prepared in Solid Works, and finite element analysis considering the von misses stress, and displacement theory is carried out to find the effects of external loads on the motors and critical components of the fixture. The analysis where performed based on load calculated to be of 580.75 N, which gives stresses ranging of 1.466 to 117.7 MPa in the components. The project goal underscores the advantages of automation in drilling, including identifying and correcting errors occurring due to manual handling of systems. This project raises procedures for maintaining, setting up the work and work holding devices to get the job done accurately

Influence of External Loads on Thin Film Cracking

2004 ◽  
Author(s):  
Srinath S. Chakravarthy ◽  
Eric H. Jordan ◽  
Wilson K. S. Chiu
Keyword(s):  
Thin Film ◽  
External Load ◽  
Crack Arrest ◽  
External Loading ◽  
Element Analysis ◽  
Film Cracking ◽  
Two Parameters ◽  
Improved Accuracy ◽  
External Loads

Cracking in thin films under the combined influence of residual stress and an external load is examined. An improved accuracy version of the existing solution for substrate cracking absent the external load is provided. A superposition scheme that uses the solution for substrate cracking and other existing published solutions is presented for the determination of the energy release rate. The superposition scheme is validated using finite element analysis, and conditions under which the superposition scheme is valid are discussed. Crack arrest is examined and two parameters that determine the possibility of crack arrest are identified. The influence of external loading on channelling behavior in the substrate is discussed.

Total-Reflection X-Ray Fluorescence Spectrometry (TXRF): Application to Elemental Profiles on Trace Evidence and Microsamples

1996 ◽  
Vol 54 ◽  
pp. 430-431
Author(s):  
Thomas A. Kubic MS, JD ◽  
JoAnn Buscaglia MS ◽  
Ulrich Reus
Keyword(s):  
Dynamic Range ◽  
Forensic Analysis ◽  
Total Reflection ◽  
Fluorescence Spectrometry ◽  
Proficiency Tests ◽  
Element Analysis ◽  
X Ray ◽  
Accuracy And Precision ◽  
Quantitative Screening ◽  
Improved Accuracy

Total-Reflection X-ray Fluorescence spectrometry has been available as commercial instrumentation for the past few years. Since that time investigations and research has been conducted on the application of the technique particularly to problems involving micro samples such as in conservation and forensic analysis.Elemental characterization of paint pigments, glass samples, textile fibers and liquid inclusions have been performed.The EXTRA IIA TXRF spectrometer has inherent potential for the microanalysis. This instrumentation allows for simultaneous multi-element analysis for elements Phosphorus to Uranium with instrument detection levels (IDLs) less than or equal to 10 picograms for 50 of these elements.Qualitative and semi-quantitative screening are possible with little sample preparation, while dissolved samples result in improved accuracy and precision with a dynamic range of five orders of magnitude without multiple dilutions.This paper briefly reviews the principal and theory of TXRF, the operation of this instrument and its advantages over other quantitative elemental analysis techniques for these types of samples. Data demonstrating the comparable results obtained with the EXTRA IIA to that of ICP, AA, and NAA methods on samples supplied as proficiency tests will be presented. No difference in the quantitative results was exhibited between the reference and test data at a 95% confidence level.

Finite Element Analysis of Pipe Bends under External Loads

2017 ◽  
pp. 209-238
Author(s):  
Sumesh S. ◽  
A. R. Veerappan ◽  
S. Shanmugam
Keyword(s):  
Finite Element Analysis ◽  
Plastic Deformation ◽  
Finite Element ◽  
High Pressure ◽  
Experimental Investigations ◽  
Toxic Substances ◽  
Element Analysis ◽  
Piping Systems ◽  
Critical Components ◽  
External Loads

Pipelines are being used to convey different sorts of fluids from hazardous and toxic substances to high pressure steam. Piping systems are subjected to various external loads leading to major failures with gross plastic deformation. Pipe bends are incorporated into piping systems not only to change the direction of flow but also to provide flexibility, hence they are considered to be critical components and its safe design under various loads becomes important. Earlier studies of pipe bends utilized analytical methods to determine the plastic loads. The evolution of FEM and the advancements in computational capabilities have enabled analysts to generate large number of data which is expensive and time consuming with experimental investigations. In this chapter, the major studies on pipe bends by various researchers are explored. Different studies on pipe bends namely stress analysis and the influence of geometric shape imperfections are also presented.

Computer Modeling of a Tire under Cornering Loads

1989 ◽  
Vol 17 (2) ◽  
pp. 86-99 ◽  
Author(s):  
I. Gardner ◽  
M. Theves
Keyword(s):  
Finite Element Analysis ◽  
Geometric Approach ◽  
Lateral Force ◽  
Slip Angle ◽  
Element Analysis ◽  
Pressure Distributions ◽  
Slip Effects ◽  
Improved Accuracy ◽  
Nonlinear Geometric ◽  
Good Agreement

Abstract During a cornering maneuver by a vehicle, high forces are exerted on the tire's footprint and in the contact zone between the tire and the rim. To optimize the design of these components, a method is presented whereby the forces at the tire-rim interface and between the tire and roadway may be predicted using finite element analysis. The cornering tire is modeled quasi-statically using a nonlinear geometric approach, with a lateral force and a slip angle applied to the spindle of the wheel to simulate the cornering loads. These values were obtained experimentally from a force and moment machine. This procedure avoids the need for a costly dynamic analysis. Good agreement was obtained with experimental results for self-aligning torque, giving confidence in the results obtained in the tire footprint and at the rim. The model allows prediction of the geometry and of the pressure distributions in the footprint, since friction and slip effects in this area were considered. The model lends itself to further refinement for improved accuracy and additional applications.

Stress Concentration at the Root of Bolt Thread

2010 ◽  
Author(s):  
Yasumasa Shoji ◽  
Toshiyuki Sawa
Keyword(s):  
Finite Element Analysis ◽  
Stress Concentration ◽  
Concentration Factor ◽  
The Other ◽  
Special Technique ◽  
Allowable Stress ◽  
Element Analysis ◽  
Bolt Stress ◽  
Thread Root ◽  
External Loads

The bolt strength is determined based on the concentrated bolt stress at the thread roots. The allowable stress is determined so that the thread root will not yield by the pretension and the external loads, using the stress concentration factor obtained as 3 to 5 from experiments. However, the concentration factor is not clear so far, as it is quite difficult to measure the stress at such a localized region. On the other hand, structural analysis, namely finite element analysis, has the possibility to provide the most-likely stress at the thread root. In this paper, a special technique, a.k.a. submodelling, is used to calculate the stress distribution at thread surfaces very precisely. The result will be useful to solve any stress related problems.

scholarly journals Comparison Of FEA Simulations And Experimental Results For As-Built Additively Manufactured Dogbone Specimens

2021 ◽  
Author(s):  
Prathamesh Baikerikar ◽  
Cameron J Turner
Keyword(s):  
Fused Deposition Modeling ◽  
Experimental Tests ◽  
Continuum Models ◽  
Element Analysis ◽  
Fused Deposition ◽  
Accuracy And Precision ◽  
Structure Strength ◽  
Deposition Modeling ◽  
End Use ◽  
Strength And Stiffness

Abstract Parts built using Fused Deposition Modeling (FDM – an additive manufacturing technology) differ from their design model in terms of their microstructure and material properties. These differences lead to a certain amount of ambiguity regarding the structure, strength and stiffness of the final FDM part. Increasing use of FDM parts as end use products, necessitates accurate simulations and analyses during part design. However, analysis methods such as Finite Element Analysis, are used for analysis of continuum models, and may not accurately represent the non-continuous non-linear FDM parts. Therefore, it is necessary to determine the accuracy and precision of FEA for FDM parts. The goal of this study is to compare FEA simulations of the as-built geometries with the experimental tests of actual FDM parts. Dogbone geometries that include different infill patterns are tested under tensile loading and later simulated using FEA. This study found that FEA results are not always an accurate or reliable means of predicting FDM part behaviors.

scholarly journals Evaluation of the behavior system locator associated with a removable partial denture, finite element analysis

2018 ◽  
Vol 25 (2) ◽  
pp. 10
Author(s):  
Medardo Alexander Arenas-Chavarria ◽  
Samuel David Giraldo-Gómez ◽  
Federico Latorre-Correa ◽  
Junes Abdul Villarraga-Ossa
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Permanent Deformation ◽  
Vertical Direction ◽  
Cobalt Chromium ◽  
Removable Partial Denture ◽  
Element Analysis ◽  
Partial Denture ◽  
Solid Works ◽  
Von Mises

Aim: The purpose of this research was to evaluate the behavior of the system locator settings associated with distal extension removable partial denture lower (PPR) by finite element analysis (FEA). Materials and Methods: A Class II Kennedy 3D model using a CAD software Solid Works 2010 (SolidWorks Corp., Concord, MA, USA), and subsequently processed and analyzed by ANSYS Software version Model 14. One (1) was designed implant Tapered Screw -Vent® (ref TSVB10 Zimmer Dental-Carlsbad,CA,USA.) length x 10mm diameter 3.7mm with a 3.5mm platform, internal hexagon with its respective screw fixation; this was located at the tooth 37 as a rear pillar of a PPR, whose major connector was a lingual bar casting (alloy cobalt chromium), based combined (metal/ acrylic) with teeth to replace (37, 36 and 35). Efforts were evaluated von Mises in a 400N load. This analysis allowed assessing the performance of various prosthetic structures modeled and generated effects on bone-implant interface. Results: Differences between the values von Mises in all structures and loads were observed before there was no permanent deformation in any of them. Structures such as bone showed in normal values microstrain. Conclusions: The behavior of the PPRimplant connection, showed a favorable distribution efforts by using a PPR, subjecting it to load in the vertical direction.

scholarly journals Roaming Dogs in Ushuaia City, Tierra Del Fuego, Argentina. How Many and Why

2021 ◽  
Author(s):  
Emiliano Arona ◽  
Adrián Schiavini
Keyword(s):  
Geographical Location ◽  
Tierra Del Fuego ◽  
Abundance Index ◽  
Simple Index ◽  
Accuracy And Precision ◽  
Main Driver ◽  
Capture Recapture ◽  
The Difference ◽  
Index Estimation ◽  
Improved Accuracy

Abstract Free roaming dogs (FRD) in cities represent an increasing problem. Authorities need numbers of FRDs to evaluate policies implemented and to monitor the dog population. We estimated the number of FRD in Ushuaia city, Argentina, using a photographic capture-recapture methodology. We estimated an abundance index, the power to detect changes in the index, and modeled factors that may explain the spatial distribution of FRD and their welfare status. During three surveys, covering 72 transects along streets (9.9% of the street layout of Ushuaia), we recorded 539 different FRDs. A model with individual heterogeneity in capture-recapture probability gave 12,797 FRDs (95% CI 10,979 − 15,323), reflecting a dog:human relation of 1:6, higher than the relation recommended by the WHO. The abundance index was similar between surveys (8.13 ± 1.36, 8.38 ± 1.46 and 9.55 ± 1.28 dogs/km). The difference needed to detect changes in the index is about twice the standard error of estimates. The best model explaining dogs’ abundance included only geographical location, although two neighbourhoods with 9 transects stand out with 181 different FRDs identified. Together with the good overall dogs’ welfare status, modeling suggests that the behavior of owners is the main driver for the presence of FRDs. We recommend the use of photographic capture-recapture methodologies instead of simple index estimation, due to the small additional effort required and the improved accuracy and precision obtained. We also recommend a permanent systematic design for future surveys, increase the number of survey occasions, and improve the survey process.

High-resolution densitometry: analysis of stained albumin bands as a model for electrophoresis of serum proteins.

1984 ◽  
Vol 30 (6) ◽  
pp. 847-850 ◽  
Author(s):  
D J Epstein ◽  
W E Neeley
Keyword(s):  
Quantitative Analysis ◽  
High Resolution ◽  
Serum Proteins ◽  
Protein Electrophoresis ◽  
Accuracy And Precision ◽  
Rectangular Slit ◽  
New Instrument ◽  
Densitometry Analysis ◽  
Photodiode Array ◽  
Improved Accuracy

Abstract In discussing the principles of quantitative analysis in thin-layer media, we show that requirements for quantitative analysis are not satisfied when stained protein electrophoretic bands are scanned with a conventional rectangular-slit densitometer. We investigated a high-resolution densitometer based on a linear photodiode array as an alternative analytical tool, using stained electrophoretic bands of radio-labeled human serum albumin as a simplified model for results of serum protein electrophoresis. Identical protein bands scanned with both the high-resolution densitometer and a conventional densitometer were quantified with improved accuracy and precision by the new instrument. We also used the high-resolution densitometer to develop a computer model for performance characteristics of a rectangular-slit densitometer.

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