Redesign of Ultrasonic Block Horns for Improved Vibration Performance

1997 ◽  
Vol 119 (3) ◽  
pp. 410-414 ◽  
Author(s):  
M. Lucas ◽  
A. C. Smith
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Laser Doppler Velocimetry ◽  
Speckle Pattern ◽  
Measurement Techniques ◽  
Theoretical Data ◽  
Vibration Measurement ◽  
Electronic Speckle Pattern Interferometry ◽  
Doppler Velocimetry ◽  
Vibration Performance

Ultrasonic block horns are prone to reliability problems associated with modal activity close to the tuned operating frequency. This paper presents an approach to block horn design, which relies on two laser based vibration measurement techniques, electronic speckle pattern interferometry (ESPI) and laser doppler velocimetry (LDV) modal analysis, to validate finite element (FE) models. Block horn vibration characteristics are interpreted from experimental and theoretical data such that successful horn redesign can be achieved from modifications to the FE models.

Application of ESPI in the Vibration Analysis of Turbine Blading

1995 ◽  
Author(s):  
Robert X. Wang ◽  
Graham M. Chapman
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Vibration Analysis ◽  
Speckle Pattern ◽  
Vibration Measurement ◽  
Simplified Model ◽  
Electronic Speckle Pattern Interferometry ◽  
Coupled Modes ◽  
Element Analysis ◽  
Turbine Blading

Abstract This paper reports on the application of Electronic Speckle Pattern Interferometry (ESPI) technique in vibration measurement of turbine blading. Using the time-averaged mode of ESPI, the first six modes of a turbocharger blade with airfoil profile were identified. The effect of the complicated profile of the blade was established by studying simplified model blades. Coupled modes were identified and successfully separated. Experimental results are compared with those obtained using finite element analysis.

Dynamic Characteristics and Finite Element Model Updating of Micromachined Torsion Structures

2013 ◽  
Vol 284-287 ◽  
pp. 1831-1835
Author(s):  
Wei Hsin Gau ◽  
Kun Nan Chen ◽  
Yunn Lin Hwang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Model Updating ◽  
Speckle Pattern ◽  
Element Model ◽  
Mode Shapes ◽  
Electronic Speckle Pattern Interferometry ◽  
Finite Element Model Updating ◽  
Element Analysis

In this paper, two experimental techniques, Electronic Speckle Pattern Interferometry and Stroboscopic Interferometry, and two different finite element analysis packages are used to measure or to analyze the frequencies and mode shapes of a micromachined, cross-shaped torsion structure. Four sets of modal data are compared and shown having a significant discrepancy in their frequency values, although their mode shapes are quite consistent. Inconsistency in the frequency results due to erroneous inputs of geometrical and material parameters to the finite element analysis can be salvaged by applying the finite element model updating procedure. Two updating cases show that the optimization sequences converge quickly and significant improvements in frequency prediction are achieved. With the inclusion of the thickness parameter, the second case yields a maximum of under 0.4% in frequency difference, and all parameters attain more reliable updated values.

scholarly journals Artificial Neural Networks Application in Modal Analysis of Tires

2013 ◽  
Vol 13 (5) ◽  
pp. 273-278 ◽  
Author(s):  
P. Koštial ◽  
Z. Jančíková ◽  
D. Bakošová ◽  
J. Valíček ◽  
M. Harničárová ◽  
...  
Keyword(s):  
Experimental Data ◽  
Neural Networks ◽  
Artificial Neural Networks ◽  
Modal Analysis ◽  
Speckle Pattern ◽  
Point Of View ◽  
Electronic Speckle Pattern Interferometry ◽  
Data Sets ◽  
Artificial Neural

Abstract The paper deals with the application of artificial neural networks (ANN) to tires’ own frequency (OF) prediction depending on a tire construction. Experimental data of OF were obtained by electronic speckle pattern interferometry (ESPI). A very good conformity of both experimental and predicted data sets is presented here. The presented ANN method applied to ESPI experimental data can effectively help designers to optimize dimensions of tires from the point of view of their noise.

Whole-field modal analysis using electronic speckle pattern interferometry

1996 ◽  
Author(s):  
George Graham ◽  
Jon N. Petzing ◽  
Margaret Lucas ◽  
John R. Tyrer
Keyword(s):  
Modal Analysis ◽  
Speckle Pattern ◽  
Electronic Speckle Pattern Interferometry

Vibration measurement based on electronic speckle pattern interferometry and radial basis function

2015 ◽  
Vol 355 ◽  
pp. 33-43 ◽  
Author(s):  
Xiangjun Dai ◽  
Xinxing Shao ◽  
Zhencen Geng ◽  
Fujun Yang ◽  
Yijun Jiang ◽  
...  
Keyword(s):  
Radial Basis Function ◽  
Basis Function ◽  
Speckle Pattern ◽  
Vibration Measurement ◽  
Electronic Speckle Pattern Interferometry ◽  
Radial Basis

Timber screw connection: Study of the strain along the interface using optical measurement techniques and simulations

BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 3859-3873
Author(s):  
Cedou Kumpenza ◽  
Andreas Ringhofer ◽  
Thomas Krenke ◽  
Adeayo Sotayo ◽  
Maximilian Pramreiter ◽  
...  
Keyword(s):  
Measurement Technique ◽  
Optical Measurement ◽  
Speckle Pattern ◽  
Measurement Techniques ◽  
Axial Loading ◽  
Electronic Speckle Pattern Interferometry ◽  
Pull Out ◽  
Grain Orientations ◽  
Thread Length ◽  
D 12

In various engineering applications, self-tapping screws are used to connect timber members. To describe their load-deformation relationship, a better understanding of the strain along the mechanical interface (i.e., timber-screw interface) is required. With a focus on the axial loading of self-tapping screws, only a few studies have dealt with the determination of the strain based on optical measurement techniques. Therefore, in the present study, the strain distribution at the timber-screw interface was monitored during pull-out tests using an optical measurement technique, called electronic speckle pattern interferometry (ESPI). Strains obtained from the ESPI measurements were compared with the results obtained from structural simulations conducted with finite element modelling (FEM). Three different types of solid spruce wood (Picea abies (L.) Karst.) specimens with different grain orientations connected with self-tapping screws (thread length lg = 130 mm, outer thread diameter d = 12 mm) were tested in withdrawal. There was a good agreement between the ESPI and FEM results, confirming that ESPI was a suitable measurement technique. The study also provided insights and results regarding the region of strain concentrations across the length of self-tapping screws.

Vibration Control in Turbomachinery Blading Using Lacing Wires

1995 ◽  
Author(s):  
Robert X. Wang ◽  
Graham M. Chapman
Keyword(s):  
Finite Element ◽  
Vibration Control ◽  
Dynamic Characteristics ◽  
Vibration Analysis ◽  
Finite Element Modelling ◽  
Speckle Pattern ◽  
Electronic Speckle Pattern Interferometry ◽  
Element Modelling ◽  
Wire Vibration ◽  
Theoretical Results

Abstract In turbomachinery practice the use of inter-blade coupling is an accepted procedure. The use of lacing wires in highly stressed short blading introduces damping and also modifies the vibration characteristics of the blading. This paper reports on a study into the dynamic characteristics of single blades with a lacing wire. Vibration analysis is carried out using finite element modelling. The theoretical results are verified using Electronic Speckle Pattern Interferometry technique (ESPI).

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