scholarly journals Evaluation of roundness error using a new method based on a small displacement screw

2014 ◽  
Vol 25 (4) ◽  
pp. 044012 ◽  
Author(s):  
Hichem Nouira ◽  
Pierre Bourdet
Keyword(s):  
New Method ◽  
Small Displacement ◽  
Roundness Error

A New Method for Roundness Control in Taper Turning Using FCC Techniques

2000 ◽  
Vol 123 (4) ◽  
pp. 567-575 ◽  
Author(s):  
Eric H. K. Fung ◽  
S. M. Yang
Keyword(s):  
Real Time ◽  
Error Compensation ◽  
Experimental Results ◽  
New Method ◽  
Two Dimensional ◽  
Turning Operations ◽  
Roundness Error ◽  
Compensatory Control ◽  
Modeling And Forecasting ◽  
Arma Modeling

This paper describes a methodology of online measuring and compensating spindle error motions without using a precalibrated master. The method is based on a combination of forecasting compensatory control (FCC) and error separation techniques. The real time recursive ARMA modeling technique is used for the modeling and forecasting of workpiece errors while the error compensation is performed by means of two-dimensional piezo-actuated tool movements. Experimental results have shown that an improvement of 42–47 percent was achieved for the roundness error of workpieces in the taper turning operations.

scholarly journals Small Displacement Measurement of Crack Opening Using One Pitch Phase Analysis (OPPA) Method

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 498 ◽  
Author(s):  
Yoshiharu Morimoto ◽  
Akihiro Masaya ◽  
Thomas Yata ◽  
Duy Anh Luong ◽  
Quentin Quarles
Keyword(s):  
Phase Analysis ◽  
Crack Width ◽  
Crack Opening ◽  
Displacement Measurement ◽  
New Method ◽  
Small Displacement

A new method to measure small displacement of crack width.

scholarly journals Influence of roundness error screw on running characteristics of sliding bearing based on SDT

2022 ◽  
Vol 355 ◽  
pp. 01021
Author(s):  
Zhenyu Chen ◽  
Wubin Xu ◽  
Bing Li
Keyword(s):  
Critical Speed ◽  
Journal Bearing ◽  
Rotor System ◽  
Small Displacement ◽  
Promoting Effect ◽  
Sliding Bearing ◽  
Roundness Error ◽  
System A ◽  
Film Characteristics ◽  
Generalized Roundness

In order to study the influence of roundness error on the oil film characteristics of journal bearing rotor system, a dynamic model of journal bearing rotor system with roundness error was established, and a new generalized roundness error equation is derived based on the small displacement screw (SDT) theory. And the influence of roundness error screw parameter dx represented by SDT on critical speed and stability of sliding bearing is analyzed emphatically. The results show that the existence of journal roundness error is beneficial to the bearing capacity and stability of sliding bearing rotor system to a certain extent, and with the increase of roundness error screw parameter, its promoting effect is more obvious; At the same time, the critical speed of the system will increase with the increase of screw parameter, especially when eccentricity ε>0.6; And when Sommerfeld number S>0.6, the roundness error of journal has little influence on stability.

Selective Sampling and Orientation of Non-Homogeneous Tissues

1968 ◽  
Vol 26 ◽  
pp. 98-99
Author(s):  
C. C. Clawson ◽  
L. W. Anderson ◽  
R. A. Good
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Light Microscopy ◽  
Random Sampling ◽  
New Method ◽  
Microscope Examination ◽  
Small Areas ◽  
Selective Sampling ◽  
Large Numbers ◽  
Specific Orientation

Investigations which require electron microscope examination of a few specific areas of non-homogeneous tissues make random sampling of small blocks an inefficient and unrewarding procedure. Therefore, several investigators have devised methods which allow obtaining sample blocks for electron microscopy from region of tissue previously identified by light microscopy of present here techniques which make possible: 1) sampling tissue for electron microscopy from selected areas previously identified by light microscopy of relatively large pieces of tissue; 2) dehydration and embedding large numbers of individually identified blocks while keeping each one separate; 3) a new method of maintaining specific orientation of blocks during embedding; 4) special light microscopic staining or fluorescent procedures and electron microscopy on immediately adjacent small areas of tissue.

A Device for Magnification Measurement

1972 ◽  
Vol 30 ◽  
pp. 622-623
Author(s):  
J.A. Eades ◽  
A. van Dun
Keyword(s):  
Electron Microscope ◽  
Small Displacement ◽  
Private Communication ◽  
Piezoelectric Crystal ◽  
Double Exposure ◽  
Standard Methods ◽  
Elegant Method ◽  
The Right ◽  
Piezo Electric

The measurement of magnification in the electron microscope is always troublesome especially when a goniometer stage is in use, since there can be wide variations from calibrated values. One elegant method (L.M.Brown, private communication) of avoiding the difficulties of standard methods would be to fit a device which displaces the specimen a small but known distance and recording the displacement by a double exposure. Such a device would obviate the need for changing the specimen and guarantee that the magnification was measured under precisely the conditions used.Such a small displacement could be produced by any suitable transducer mounted in one of the specimen translation mechanisms. In the present case a piezoelectric crystal was used. Modern synthetic piezo electric ceramics readily give reproducible displacements in the right range for quite modest voltages (for example: Joyce and Wilson, 1969).

Observation of faint contrast at planar faults in alloys

1978 ◽  
Vol 36 (1) ◽  
pp. 340-341
Author(s):  
K. Kuroda ◽  
Y. Tomokiyo ◽  
T. Kumano ◽  
T. Eguchi
Keyword(s):  
Reciprocal Lattice ◽  
Beam Theory ◽  
Al Alloys ◽  
Small Displacement ◽  
Electron Microscopic ◽  
Lattice Vector ◽  
Fringe Contrast ◽  
Planar Fault ◽  
Lattice Displacement ◽  
The Many

The contrast in electron microscopic images of planar faults in a crystal is characterized by a phase factor , where is the reciprocal lattice vector of the operating reflection, and the lattice displacement due to the fault under consideration. Within the two-beam theory a planar fault with an integer value of is invisible, but a detectable contrast is expected when the many-beam dynamical effect is not negligibly small. A weak fringe contrast is also expected when differs slightly from an integer owing to an additional small displacement of the lattice across the fault. These faint contrasts are termed as many-beam contrasts in the former case, and as ε fringe contrasts in the latter. In the present work stacking faults in Cu-Al alloys and antiphase boundaries (APB) in CuZn, FeCo and Fe-Al alloys were observed under such conditions as mentioned above, and the results were compared with the image profiles of the faults calculated in the systematic ten-beam approximation.

Superstructures and ordering phenomena in ceramic superconductors

1996 ◽  
Vol 54 ◽  
pp. 710-711
Author(s):  
R. Gronsky
Keyword(s):  
Domain Growth ◽  
Small Displacement ◽  
Small Scale ◽  
Ceramic Superconductors ◽  
Oxygen Sublattices ◽  
Tweed Contrast ◽  
Diffraction Patterns ◽  
Representative Image ◽  
Static Lattice ◽  
Modulation Wavelength

It is now well established that the phase transformation behavior of YBa2Cu3O6+δ is significantly influenced by matrix strain effects, as evidenced by the formation of accommodation twins, the occurrence of diffuse scattering in diffraction patterns, the appearance of tweed contrast in electron micrographs, and the generation of displacive modulation superstructures, all of which have been successfully modeled via simple Monte Carlo simulations. The model is based upon a static lattice formulation with two types of excitations, one of which is a change in oxygen occupancy, and the other a small displacement of both the copper and oxygen sublattices. Results of these simulations show that a displacive superstructure forms very rapidly in a morphology of finely textured domains, followed by domain growth and a more sharply defined modulation wavelength, ultimately evolving into a strong <110> tweed with 5 nm to 7 nm period. What is new about these findings is the revelation that both the small-scale deformation superstructures and coarser tweed morphologies can result from displacive modulations in ordered YBa2Cu3O6+δ and need not be restricted to domain coarsening of the disordered phase. Figures 1 and 2 show a representative image and diffraction pattern for fully-ordered (δ = 1) YBa2Cu3O6+δ associated with a long-period <110> modulation.

Sign in / Sign up

Export Citation Format

Share Document