scholarly journals Phantom experiments of axial strain measurements using multidimensional autocorrelation method, multidimensional Doppler method and direct strain measurement method

2009 ◽  
Vol 30 (2) ◽  
pp. 117-123 ◽  
Author(s):  
Chikayoshi Sumi ◽  
Tomonori Ebisawa
Keyword(s):  
Strain Measurement ◽  
Measurement Method ◽  
Axial Strain ◽  
Strain Measurements ◽  
Doppler Method ◽  
Autocorrelation Method ◽  
Phantom Experiments

Non-Contacting Bi-Axial Strain Measurement Method on Steel Pipeline

2008 ◽  
Author(s):  
Stephen Westwood ◽  
Michael Martens ◽  
Richard Kania ◽  
David Topp ◽  
Raymond Kare´ ◽  
...  
Keyword(s):  
Internal Pressure ◽  
Strain Measurement ◽  
Measurement Method ◽  
Axial Strain ◽  
Compressive Load ◽  
Ferromagnetic Materials ◽  
Strain Gauges ◽  
Steel Pipeline ◽  
Strain Measurements ◽  
Axial Tensile

The StressProbe is a non-contacting electromagnetic tool that responds to material strain in ferromagnetic materials. Previous studies have concentrated on uni-axial strain measurements; in this study, we extend the scope of work by measuring bi-axial strains on a pipe specimen subject to internal pressure and to a displacement-controlled, axial tensile/compressive load. Specified pressure and load combinations were obtained, and measurements from the StressProbe were compared to those from tri-axial strain gauges installed on the pipe specimen. In this paper, we present the theory behind this measurement method and the results from this study. Also discussed are measurement applications both inside and outside the pipe specimen.

Axial Strains in FRP-Confined Normal- and High-Strength Concrete: An Examination of Strain Measurement Methods

2014 ◽  
Vol 919-921 ◽  
pp. 23-28 ◽  
Author(s):  
Thomas Vincent ◽  
Togay Ozbakkloglu
Keyword(s):  
Cross Sections ◽  
Strain Measurement ◽  
High Strength Concrete ◽  
Measurement Method ◽  
Axial Strain ◽  
High Strength ◽  
Measurement Methods ◽  
Strength Concrete ◽  
Highly Sensitive ◽  
Variable Displacement

This paper presents an experimental investigation into the axial strain measurement method of fiber reinforced polymer (FRP)-confined normal-and high-strength concrete (NSC and HSC). A total of 15 FRP-confined concrete specimens with circular cross-sections were tested under monotonic axial compression. Axial strain recordings were compared on specimens instrumented with three different measurement methods: axial strain gauges and full-and mid-height linear variable displacement transformers (LVDTs). The ultimate conditions are tabulated for each measurement method and key experimental outcomes discussed. The results indicate that axial strains of FRP-confined HSC are highly sensitive to the instrumentation arrangement and significant differences occur in the results obtained from different measurement methods.

Strain Measurement by X-ray Diffraction Methods

1949 ◽  
Vol 1 (3) ◽  
pp. 211-224
Author(s):  
G. B. Greenough
Keyword(s):  
Strain Measurement ◽  
Plastic Anisotropy ◽  
Stress And Strain ◽  
Routine Method ◽  
X Ray Diffraction ◽  
Strain Measurements ◽  
X Ray ◽  
The Past ◽  
Polycrystalline Metals ◽  
The Individual

SummaryMany papers have been written on the measurement of strain by X-ray diffraction methods and on the interpretation of these strains in terms of stresses. Whereas, during the past few years, the experimental methods of determining the strains have. remained largely unchanged, research has shown that the older techniques for calculating stresses from strains are not always valid.In this paper an attempt is made to describe some of the principles of strain measurement by X-ray diffraction methods to those who are unfamiliar with the methods. The types of stress and strain systems which may exist in polycrystalline metals are then considered, particular attention being paid to the effect of the elastic and plastic anisotropy of the individual crystals. Some indication is given as to how the earlier methods of interpreting X-ray strain measurements should be modified, but no rigid routine method is proposed for use in a general case.

An Approach to Analyse Errors Introduced in the Random Grid Strain Measurement Method

Strain ◽  
2008 ◽  
Vol 46 (3) ◽  
pp. 258-266 ◽  
Author(s):  
A. P. Iliopoulos ◽  
N. P. Andrianopoulos
Keyword(s):  
Strain Measurement ◽  
Measurement Method ◽  
Random Grid

scholarly journals Strain Measurement Based on Speeded-up Robust Feature Algorithm Applied to Microimages from a Smartphone-Based Microscope

Sensors ◽  
2020 ◽  
Vol 20 (10) ◽  
pp. 2805 ◽  
Author(s):  
Botao Xie ◽  
Jinke Li ◽  
Xuefeng Zhao
Keyword(s):  
Health Monitoring ◽  
Strain Measurement ◽  
Measurement Method ◽  
Feature Points ◽  
Matching Effect ◽  
Point Tracking ◽  
Feature Point Tracking ◽  
M Estimator ◽  
Practical Engineering ◽  
Accuracy And Stability

The objective of this study is to evaluate and improve the accuracy and stability of a strain measurement method that uses the speeded-up robust feature (SURF) method to trace the displacement of feature points in microimages and obtain the strain in objects. The microimages were acquired using a smartphone with a portable microscope, which has a broad prospect of application. An experiment was performed using an unpacked optical fiber as the experimental carrier. The matching effect of the SURF method was analyzed in the microimage, and the M-estimator sample consensus (MSAC) algorithm was used to reject outliers generated by SURF. The results indicated that the accuracy of strain measurement using the proposed method is improved by modifying the feature point tracking method and measurement method. When compared with the fiber Bragg grating (FBG) data, the maximum standard error corresponded to 2.5 με, which satisfies the requirement of structural health monitoring (SHM) in practical engineering.

The Measurement of Dynamic Stress for The Top-Cutter Machine of Cotton

2010 ◽  
Vol 34-35 ◽  
pp. 1323-1327 ◽  
Author(s):  
Chun Mei Xu ◽  
Chun Yao Wang ◽  
Fa Chen ◽  
Min Lei ◽  
Yong Xin Jiang ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Strain Measurement ◽  
Measurement Method ◽  
Dynamic Stress ◽  
Stress Condition ◽  
Dynamic Strain ◽  
Measurement Result

In this paper, we used the dynamic strain measurement method to measure the top-cutter machine of cotton’s stress under its working state. With sorting out data and analyzing it, we obtained the stress condition of the framing and the working parts. And the measurement result could be used to analyze the axle’s fatigue strength and check whether it was safe or not. It provided integrant basis for the further design of the machine.

Measurements of Residual Stresses in Low-Stress Silicon Nitride Thin Films Using Micro-Rotating Structures

1996 ◽  
Vol 444 ◽  
Author(s):  
Xin Zhang ◽  
Yitshak Zohar ◽  
Tong-Yi Zhang
Keyword(s):  
Thin Films ◽  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Silicon Nitride ◽  
Film Thickness ◽  
Strain Measurement ◽  
Strain Measurements ◽  
Micro Structures ◽  
Gas Ratio

AbstractA variety of rotating micro structures were designed, fabricated and characterized for residual-stress (or strain) measurements in low-stress silicon nitride thin films, deposited by LPCVD on silicon wafers. The sensitivities of the micro structures were calculated by finite element method (FEM) and verified experimentally. The results were further confirmed by utilizing the wafer-curvature method for stress measurements. The size of the structures enables local residual-stress (or strain) measurement. The stress level depends on both the film thickness and the gas ratio and also varies with the location on the wafer.

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