A Comparison of the Acoustic Emission Generated from the Fracture and Decohesion of Graphite Nodules with Theoretical Predictions

2009 ◽  
pp. 252-252-9
Author(s):  
SH Carpenter ◽  
Z Zhu
Keyword(s):  
Acoustic Emission ◽  
Theoretical Predictions

Modeling and Experimental Analysis of Acoustic Emission from Metal Cutting

1989 ◽  
Vol 111 (3) ◽  
pp. 229-237 ◽  
Author(s):  
R. Teti ◽  
D. Dornfeld
Keyword(s):  
Acoustic Emission ◽  
Experimental Analysis ◽  
Metal Cutting ◽  
Experimental Results ◽  
Cutting Conditions ◽  
Tool Geometry ◽  
Simple Manner ◽  
Work Material ◽  
Theoretical Predictions

Testing parameters characterizing acoustic emission (AE) detected during metal cutting may be theoretically correlated, in a simple manner, to work material properites, cutting conditions, and tool geometry. Experimental results, obtained during turning by different researchers using different AE techniques, are presented and critically assessed with reference to their reciprocal agreement as well as their agreement with theoretical predictions. A review of current methods for AE analysis is also presented and the correlations between different AE parameters and energy and power of the detected signals are reported.

Modeling and Analysis of Acoustic Emission in Diamond Turning

1996 ◽  
Vol 118 (2) ◽  
pp. 199-207 ◽  
Author(s):  
J. J. Liu ◽  
D. A. Dornfeld
Keyword(s):  
Acoustic Emission ◽  
Energy Content ◽  
Rolling Process ◽  
Quantitative Model ◽  
Diamond Turning ◽  
Modeling And Analysis ◽  
Process Characterization ◽  
Theoretical Predictions ◽  
Frequency Components ◽  
Ae Signal

To estimate the acoustic emission (AE) energy released in diamond turning, a quantitative model, which contains the energy from primary, secondary, tertiary cutting zones and the rubbing zones, is proposed and compared with experimental data. The purpose of this model is to assist in process characterization and monitoring. As part of the model developed here the plowing energy, that is, the energy released in the tertiary zone, is approximated by the forming load in the rolling process where the roller is stationary. This load is theoretically calculated by the upper bound method and used in the estimation. A series of diamond turning tests were conducted to check the validity of the model. It was found that the energy content of the AE signal is close to the theoretical predictions. The spectral analysis of the AE signal in these tests is also carried out. It was noticed that when the diamond tool first touches the workpiece without producing any chip, more high frequency components were observed and this stage was recognized as the rubbing stage. The results further support the previous findings, that is, that abnormal rubbing always increases the mean frequency of the raw AE signal.

Toughening of Cement-Based Materials with Fiber Reinforcement

1990 ◽  
Vol 211 ◽  
Author(s):  
S. P. Shah
Keyword(s):  
Acoustic Emission ◽  
Image Analysis ◽  
Fiber Reinforcement ◽  
Damage Localization ◽  
Fiber Volume ◽  
High Fiber ◽  
Quantitative Image ◽  
Cement Based Materials ◽  
Theoretical Predictions ◽  
Good Agreement

AbstractToughening of cement-based materials when reinforced with relatively high fiber volume is studied in the paper. Toughening mechanisms of composites have been experimentally studied by quantitative image analysis, laser holographic interferometry, and acoustic emission. It is found that damage localization in cement-based materials can be greatly reduced by the use of fibers. Based on fracture mechanism observed, an R-curve approach has been proposed to predict toughening of matrices due to fiber reinforcement. Theoretical predictions show good agreement with experimental results.

scholarly journals Damage Evolution Analysis in a “Spaghetti” Bridge Model Using the Acoustic Emission Technique

2021 ◽  
Vol 11 (6) ◽  
pp. 2718
Author(s):  
Boris Nahuel Rojo Tanzi ◽  
Mario Sobczyk ◽  
Tiago Becker ◽  
Luis Alberto Segovia González ◽  
Sabrina Vantadori ◽  
...  
Keyword(s):  
Acoustic Emission ◽  
Geometric Distribution ◽  
Frequency Variation ◽  
Loading Test ◽  
Evolution Analysis ◽  
Bridge Model ◽  
Theoretical Predictions ◽  
Damage Process ◽  
Damage Processes ◽  
Ae Signals

This paper applies the Acoustic Emission (AE) Technique to analyze the damage process in a one-meter span bridge model that was built from spaghetti sticks during a loading test. The AE signals are analyzed in terms of four coefficients that are evaluated as predictors of structure failure, with frequency variation appearing to be the strongest indicator of instability. The AE data are also compared to theoretical predictions that are given by the Bundle Model, confirming that underlying general patterns in damage processes are highly influenced by the geometric distribution of the structure and the loading pattern that is applied to it.

Microcalorimeters for X-Ray Spectroscopy

1988 ◽  
Vol 102 ◽  
pp. 41
Author(s):  
E. Silver ◽  
C. Hailey ◽  
S. Labov ◽  
N. Madden ◽  
D. Landis ◽  
...  
Keyword(s):  
High Resolution ◽  
High Efficiency ◽  
Thermal Response ◽  
Low Noise ◽  
High Resolution Spectroscopy ◽  
Superconducting Transition ◽  
Sapphire Substrates ◽  
Laboratory Plasmas ◽  
Adiabatic Demagnetization ◽  
Theoretical Predictions

The merits of microcalorimetry below 1°K for high resolution spectroscopy has become widely recognized on theoretical grounds. By combining the high efficiency, broadband spectral sensitivity of traditional photoelectric detectors with the high resolution capabilities characteristic of dispersive spectrometers, the microcalorimeter could potentially revolutionize spectroscopic measurements of astrophysical and laboratory plasmas. In actuality, however, the performance of prototype instruments has fallen short of theoretical predictions and practical detectors are still unavailable for use as laboratory and space-based instruments. These issues are currently being addressed by the new collaborative initiative between LLNL, LBL, U.C.I., U.C.B., and U.C.D.. Microcalorimeters of various types are being developed and tested at temperatures of 1.4, 0.3, and 0.1°K. These include monolithic devices made from NTD Germanium and composite configurations using sapphire substrates with temperature sensors fabricated from NTD Germanium, evaporative films of Germanium-Gold alloy, or material with superconducting transition edges. A new approache to low noise pulse counting electronics has been developed that allows the ultimate speed of the device to be determined solely by the detector thermal response and geometry. Our laboratory studies of the thermal and resistive properties of these and other candidate materials should enable us to characterize the pulse shape and subsequently predict the ultimate performance. We are building a compact adiabatic demagnetization refrigerator for conveniently reaching 0.1°K in the laboratory and for use in future satellite-borne missions. A description of this instrument together with results from our most recent experiments will be presented.

A crystallographic analysis of the CoSi/Si(111) interface using Transmission Electron Microscopy

1990 ◽  
Vol 48 (4) ◽  
pp. 574-575
Author(s):  
A.C. Daykin ◽  
C.J. Kiely ◽  
R.C. Pond ◽  
J.L. Batstone
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Defect Structure ◽  
Room Temperature ◽  
Theoretical Method ◽  
Crystallographic Analysis ◽  
Si Substrate ◽  
Transmission Electron ◽  
Theoretical Predictions

When CoSi2 is grown onto a Si(111) surface it can form in two distinct orientations. A-type CoSi2 has the same orientation as the Si substrate and B-type is rotated by 180° degrees about the [111] surface normal.One method of producing epitaxial CoSi2 is to deposit Co at room temperature and anneal to 650°C.If greater than 10Å of Co is deposited then both A and B-type CoSi2 form via a number of intermediate silicides .The literature suggests that the co-existence of A and B-type CoSi2 is in some way linked to these intermediate silicides analogous to the NiSi2/Si(111) system. The phase which forms prior to complete CoSi2 formation is CoSi. This paper is a crystallographic analysis of the CoSi2/Si(l11) bicrystal using a theoretical method developed by Pond. Transmission electron microscopy (TEM) has been used to verify the theoretical predictions and to characterise the defect structure at the interface.

Combining Defaults and Transparency Information to Increase Policy Compliance

2020 ◽  
Vol 51 (5) ◽  
pp. 354-359 ◽  
Author(s):  
Yavor Paunov ◽  
Michaela Wänke ◽  
Tobias Vogel
Keyword(s):  
Independent Effect ◽  
Online Experiment ◽  
Policy Compliance ◽  
Empirical Question ◽  
Theoretical Predictions

Abstract. Combining the strengths of defaults and transparency information is a potentially powerful way to induce policy compliance. Despite negative theoretical predictions, a recent line of research revealed that default nudges may become more effective if people are informed why they should exhibit the targeted behavior. Yet, it is an open empirical question whether the increase in compliance came from setting a default and consequently disclosing it, or the provided information was sufficient to deliver the effect on its own. Results from an online experiment indicate that both defaulting and transparency information exert a statistically independent effect on compliance, with highest compliance rates observed in the combined condition. Practical and theoretical implications are discussed.

Sign in / Sign up

Export Citation Format

Share Document