Elastic characterization of isotropic materials by a single test based on the experimental determination of natural frequencies using laser interferometry

1997 ◽  
Vol 101 (4) ◽  
pp. 1990-1993 ◽  
Author(s):  
A. Bayón ◽  
A. Varadé ◽  
F. Gascón
Keyword(s):  
Experimental Determination ◽  
Natural Frequencies ◽  
Laser Interferometry ◽  
Single Test ◽  
Isotropic Materials

Experimental Determination Of Relaxation Of Interphase Interfaces In Oxide Eutectics

1991 ◽  
Vol 238 ◽  
Author(s):  
Vinayak P. Dravid ◽  
V. Ravikumar ◽  
G. Dhalenne ◽  
A. Revcolevschi
Keyword(s):  
Experimental Determination ◽  
Interface Structure ◽  
Low Energy ◽  
Three Dimensions ◽  
Directionally Solidified ◽  
Lamellar Morphology ◽  
Analytical Tem ◽  
Directionally Solidified Eutectics

ABSTRACTInterphase interfaces in the directionally solidified eutectics.(DSEs) of NiO-ZrO2(CaO), NiO-Y2O3 and MnO-ZrO2 have been investigated using a variety of TEM techniques. The unique lamellar morphology of the DSEs allows characterization of interfaces and identification of relaxations along multiple directions, aiding visualization of interface structure in three dimensions. Possible low energy interface orientations were identified through examination of facets. The low energy interface planes almost invariably correspond to polar surfaces of adjacent crystals. An attempt has been made to experimentally identify the variety of interfacial relaxation mechanisms using a variety of analytical TEM techniques and only HRTEM results are summarized in this paper. It was found that most of the DSE systems exhibit very little relaxation and possess tight interface cores.

Characterization of Chemical Looping Pilot Plant Performance via Experimental Determination of Solids Conversion

2009 ◽  
Vol 23 (3) ◽  
pp. 1450-1455 ◽  
Author(s):  
Philipp Kolbitsch ◽  
Tobias Pröll ◽  
Johannes Bolhar-Nordenkampf ◽  
Hermann Hofbauer
Keyword(s):  
Experimental Determination ◽  
Pilot Plant ◽  
Plant Performance ◽  
Chemical Looping

Experimental Determination of the Complete Dynamical Properties of a Two-Degree-Of-Freedom Model Having Nearly Coincident Natural Frequencies

1967 ◽  
Vol 9 (5) ◽  
pp. 402-413 ◽  
Author(s):  
R. W. Traill-Nash ◽  
G. Long ◽  
C. M. Bailey
Keyword(s):  
Experimental Investigation ◽  
Experimental Determination ◽  
Natural Frequencies ◽  
Degree Of Freedom ◽  
Influence Coefficients ◽  
Stiffness Properties ◽  
Modes Of Vibration ◽  
Dynamical Properties ◽  
Two Degree Of Freedom

Existing techniques of resonance testing have shown a marked inability to find the principal modes, natural frequencies and levels of damping in a structure which possesses two or more close natural frequencies (1)§. This paper describes an experimental investigation on a two-degree-of-freedom model of a technique which makes use of dynamical influence coefficients (or receptances) measured at a number of stations on the structure (2) (3) (4) (5). The measured coefficients are used to calculate natural frequencies and modes of vibration, and the mass, damping and stiffness properties of the system. Several model configurations having different natural frequency separations were tested and no special difficulty resulted when natural frequencies were close or even coincident.

scholarly journals Some problems of characterization of a solid surface via the surface free energy changes

2017 ◽  
Vol 35 (7-8) ◽  
pp. 647-659 ◽  
Author(s):  
Emil Chibowski
Keyword(s):  
Contact Angle ◽  
Free Energy ◽  
Experimental Determination ◽  
Surface Free Energy ◽  
Solid Surface ◽  
Contact Angles ◽  
Absolute Value ◽  
Receding Contact

During the processes occurring at a solid surface, the changes in the surface free energy take place. The knowledge about surface free energy is very helpful for understanding the processes taking place on the surface. However, experimental determination of solid surface free energy is still not a fully solved problem. In this paper, some problems dealing with calculation of solid surface free energy from contact angle are discussed based on literature values of advancing and receding contact angles measured on four different fluoropolymers surface. The four approaches most often used for the calculation are described and especial focus on the approach in which both the advancing and receding contact angles is paid. It is concluded that using probing liquids the absolute value of solid surface free energy cannot be determined. However, the determined apparent values of the energy are very helpful to understand the conditions necessary for a given process to occur.

scholarly journals Natural Frequency Computation of Parallel Robots

2015 ◽  
Vol 10 (2) ◽  
Author(s):  
Coralie Germain ◽  
Sébastien Briot ◽  
Stéphane Caro ◽  
Philippe Wenger
Keyword(s):  
Natural Frequencies ◽  
Parallel Manipulators ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Stiffness Matrices ◽  
The Subject ◽  
Three Degree Of Freedom ◽  
And Control

The characterization of the elastodynamic behavior and natural frequencies of parallel robots is a crucial point. Accurate elastodynamic models of parallel robots are useful at both their design and control stages in order to define their optimal dimensions and shapes while improving their vibratory behavior. Several methods exist to write the elastodynamic model of manipulators. However, those methods do not provide a straightforward way to write the Jacobian matrices related to the kinematic constraints of parallel manipulators. Therefore, the subject of this paper is about a systematic method for the determination of the mass and stiffness matrices of any parallel robot in stationary configurations. The proposed method is used to express the mass and stiffness matrices of the Nantes Variable Actuation Robot (NaVARo), a three-degree-of-freedom (3DOF) planar parallel robot with variable actuation schemes, developed at IRCCyN. Then, its natural frequencies are evaluated and compared with those obtained from both Cast3m software and experimentally.

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