scholarly journals Simultaneous measurements of in‐plane and out‐of‐plane surface displacements of shell vibrations at several points by an array of miniature laser probe heads

1993 ◽  
Vol 93 (4) ◽  
pp. 2389-2389
Author(s):  
Ming Yang ◽  
Yves H. Berthelot ◽  
Jacek Jarzynski
Keyword(s):  
Plane Surface ◽  
Laser Probe ◽  
Simultaneous Measurements ◽  
Surface Displacements ◽  
Out Of Plane

Identification of Critical Surface Displacement Parameters for Characterization of Subsurface Flaws

2002 ◽  
Author(s):  
Paul D. Herrington ◽  
Paul J. Schilling ◽  
Melody A. Verges ◽  
Prashanth K. Durgam
Keyword(s):  
Plane Surface ◽  
Surface Displacement ◽  
Homogeneous Material ◽  
Critical Surface ◽  
Near Surface ◽  
Surface Displacements ◽  
Measuring Surface ◽  
Out Of Plane ◽  
Subsurface Geometry

Several NDE methods provide accurate techniques for measuring surface displacements. While these techniques have been successful in identification of near-surface embedded flaws, they generally offer little in terms of characterization of the flaws. The ability to characterize embedded flaws from measurements of surface displacements would offer substantial benefits, especially in terms of remaining life predictions. This paper focuses on the identification of critical out-of-plane surface displacement parameters, and assessment of the potential to characterize subsurface flaw geometry based on these parameters. Finite element models of a homogeneous material have been created that vary the embedded flaw size and edge distance. The results suggest that there is potential to characterize the subsurface geometry from the surface displacement parameters.

scholarly journals Unlocking surface octahedral tilt in two-dimensional Ruddlesden-Popper perovskites

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Yan Shao ◽  
Wei Gao ◽  
Hejin Yan ◽  
Runlai Li ◽  
Ibrahim Abdelwahab ◽  
...  
Keyword(s):  
Density Functional ◽  
Carrier Transport ◽  
Plane Surface ◽  
Structural Phase ◽  
Density Functional Theory Calculations ◽  
Spin Splitting ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Out Of Plane ◽  
Inversion Asymmetry

AbstractMolecularly soft organic-inorganic hybrid perovskites are susceptible to dynamic instabilities of the lattice called octahedral tilt, which directly impacts their carrier transport and exciton-phonon coupling. Although the structural phase transitions associated with octahedral tilt has been extensively studied in 3D hybrid halide perovskites, its impact in hybrid 2D perovskites is not well understood. Here, we used scanning tunneling microscopy (STM) to directly visualize surface octahedral tilt in freshly exfoliated 2D Ruddlesden-Popper perovskites (RPPs) across the homologous series, whereby the steric hindrance imposed by long organic cations is unlocked by exfoliation. The experimentally determined octahedral tilts from n = 1 to n = 4 RPPs from STM images are found to agree very well with out-of-plane surface octahedral tilts predicted by density functional theory calculations. The surface-enhanced octahedral tilt is correlated to excitonic redshift observed in photoluminescence (PL), and it enhances inversion asymmetry normal to the direction of quantum well and promotes Rashba spin splitting for n > 1.

A Real-Time DSPI System for Measuring Surface Deformation in Clamped Bolted Joints

2008 ◽  
Author(s):  
Aidong Meng ◽  
Sayed A. Nassar
Keyword(s):  
Real Time ◽  
Vibration Isolation ◽  
Surface Deformation ◽  
Plane Surface ◽  
Speckle Pattern ◽  
The Real ◽  
Time Deformation ◽  
Out Of Plane ◽  
Phase Data ◽  
Set Up

A Digital Speckle Pattern Interferometry (DSPI) system is developed for the real-time measuring and monitoring the out-of-plane surface deformation around tightened threaded fasteners that are used to clamp bolted assemblies. Spatial phase shifting is employed to quantitatively determine the distribution of phase data by introducing a spatial carrier fringe pattern to the speckle interferogram. This is achieved by leading the object and reference beams to two separate apertures. The configuration is also suitable for collecting the real-time deformation during bolt tightening. The experimental DSPI system is set-up with optical components on a vibration-isolation table. A Matlab software is developed for the image acquisition and phase data calculation, which yields the out-of-plane surface deformation caused by the bolt preload. An aluminum joint is used with an M12 steel fastener. For miniature screw application, however, a plastic joint is used for collecting data.

Spectroscopic evaluation of out-of-plane surface vibration bands from surface functionalization of graphite oxide by fluorination

Carbon ◽  
2014 ◽  
Vol 77 ◽  
pp. 577-591 ◽  
Author(s):  
Muge Acik ◽  
Sriram Yagneswaran ◽  
Weina Peng ◽  
Geunsik Lee ◽  
Benjamin R. Lund ◽  
...  
Keyword(s):  
Surface Functionalization ◽  
Graphite Oxide ◽  
Plane Surface ◽  
Surface Vibration ◽  
Out Of Plane

3D Digital Imaging Correlation: Applications to Tire Testing

2010 ◽  
Vol 38 (2) ◽  
pp. 100-118 ◽  
Author(s):  
Russ A. Moser ◽  
H. James Sube ◽  
John L. Turner ◽  
Paul Zakelj
Keyword(s):  
Digital Imaging ◽  
Surface Deformation ◽  
Plane Surface ◽  
Three Dimensional ◽  
Test Sample ◽  
Full Field ◽  
Surface Displacements ◽  
Deformation State ◽  
Tire Testing ◽  
Insight Into

Abstract Three-dimensional digital imaging correlation (DIC) techniques are a viable method for measuring surface displacements and strains on tires. DIC provides the capability to measure the full-field noncontact tire surface deformation and strain state, which supports multiple objectives: validation of tire models based on finite element (FE) predictions, setting targets for improving FE predictions and providing insight into the tire deformation state under static and dynamic conditions. A method for verifying the accuracy of the DIC measurement process is presented whereby a thin, rectangular test sample of rubber material is subjected to a combination of strains and rigid body motions of known amounts. Once the measurement technique is proven accurate with a simple specimen, the focus shifts to the objectives explained above. Tire surface strains will be discussed for purposes of validating model predictions of sidewall and belt edge strains. Several types of specimen geometries will be reviewed and their effect on material properties will be presented. Also, the DIC technique can provide insight into complex physical problems that may otherwise be very difficult to measure. Some examples presented here include tire sidewall standing waves at high speeds and strains near tread lugs of agricultural tires. The DIC measurement method is an accurate, noncontacting full field technique for measuring in-plane surface displacements and strains of the magnitudes encountered in tire analysis. This technique serves many functions and has become a valuable tool for both tire testing and development.

DISORDERING MECHANISMS OF THE Cu(110) SURFACE

1994 ◽  
Vol 08 (23) ◽  
pp. 3175-3204 ◽  
Author(s):  
J. MERIKOSKI ◽  
H. HÄKKINEN ◽  
M. MANNINEN ◽  
J. TIMONEN ◽  
K. KASKI
Keyword(s):  
Lattice Gas ◽  
Surface Defects ◽  
Effective Medium Theory ◽  
Plane Surface ◽  
Theoretical Work ◽  
Medium Theory ◽  
Recent Theoretical Work ◽  
Out Of Plane ◽  
Surface Vibrations ◽  
Many Body Interactions

We review recent theoretical work on the various disordering mechanisms of the Cu(110) surface. In these studies the properties of the surface, from the onset of enhanced anharmonicity in surface vibrations up to bulk melting point T M , have been studied using molecular dynamics and lattice-gas Monte Carlo methods with many-body interactions derived from the effective medium theory. Well after the onset of enhanced out-of-plane surface vibrations, clustering of surface defects is found to induce a roughening transition at T≈0.81T M , and surface premelting is found to occur at T≈0.97T M . These results suggest, that these transitions can both appear at Cu(110). The general picture of disordering as reported here for Cu(110), is expected to be valid also for other unreconstructed (110) surfaces of fcc metals.

Sign in / Sign up

Export Citation Format

Share Document