Measurement of bending stresses in shells of arbitrary shape using the reflection moiré method

2000 ◽  
Vol 40 (3) ◽  
pp. 282-288 ◽  
Author(s):  
C. A. Sciammarella ◽  
B. Trentadue ◽  
F. M. Sciammarella
Keyword(s):  
Arbitrary Shape ◽  
Bending Stresses ◽  
Moire Method ◽  
Reflection Moiré

Warpage of thin wafers using computer aided reflection moire method

2007 ◽  
Author(s):  
Chi Seng Ng ◽  
Kok Yau Chua ◽  
Meng Tong Ong ◽  
Yoke Chin Goh ◽  
Anand K. Asundi
Keyword(s):  
Computer Aided ◽  
Moire Method ◽  
Reflection Moiré

Strain measurement by the reflection-moiré method

1971 ◽  
Vol 11 (2) ◽  
pp. 86-86 ◽  
Author(s):  
M. S. Gregory ◽  
A. W. Christian ◽  
I. F. Jones
Keyword(s):  
Strain Measurement ◽  
Moire Method ◽  
Reflection Moiré

Accurate Imaging Method for Moving Target with Arbitrary Shape for Multi-Static UWB Radar

2013 ◽  
Vol E96.B (7) ◽  
pp. 2014-2023 ◽  
Author(s):  
Ryo YAMAGUCHI ◽  
Shouhei KIDERA ◽  
Tetsuo KIRIMOTO
Keyword(s):  
Arbitrary Shape ◽  
Imaging Method ◽  
Moving Target ◽  
Uwb Radar ◽  
Accurate Imaging

SYNTHESIS OF ELEMENTS OF LOAD-BEARING SYSTEMS WITH A GIVEN LEVEL OF RELIABILITY

2020 ◽  
Author(s):  
Y.P. Manshin ◽  
◽  
E.Yu. Manshina ◽  
Keyword(s):  
Strain Measurement ◽  
Field Strain ◽  
Design Element ◽  
Load Bearing ◽  
Cyclic Bending ◽  
Bending Stresses

The article considers an algorithm for analyzing the results of field strain-measurement studies of machine structures, which allows obtaining data for the modernization of elements in the form of coefficients of parameter changes. As the object of application of the method, the design element of the header was selected, which had failures due to insufficient endurance under cyclic bending stresses.

Simulation of continuous random process according to the specified sequence of extremes

2020 ◽  
Vol 86 (7) ◽  
pp. 65-71
Author(s):  
I. V. Gadolina ◽  
R. I. Zainetdinov ◽  
T. P. Gryzlova ◽  
I. M. Petrova
Keyword(s):  
Spectral Density ◽  
Random Process ◽  
Continuous Process ◽  
Continuous Processes ◽  
Regression Formula ◽  
Bending Stresses ◽  
Development And Validation ◽  
Irregular Loading ◽  
Cosine Functions ◽  
Maximum Minimum

A method has been developed for converting a discrete sequence of extrema into a continuous process. The relevancy of the problem is attributed to the necessity of an approximate estimation of spectral density in in testing materials and structures under random (irregular) loading. A great bulk of available experimental data thus can be used in development and validation of calculation methods for assessing durability in the multi-cycle region. Postulating the continuity of random stress processes and their first derivative we propose to connect piecewise the available starting points (namely, the extrema of the random process) with half-cosine functions under the condition of compatibility at the points of extrema. A distinctive feature of the method is the provision of 100% coincidence of the values and sequences of extrema in the initial discrete and simulated continuous processes. The issue of choosing the magnitude of half-periods for these half-cosine functions is addressed on the basis of information obtained from the analysis of real stress records in the form of a regression equation linking half-periods and half-ranges for some realizations of the random process for transport vehicles. The regression dependences of the half-periods and semi-ranges of bending stresses (part of a railway train) and torsion (torsion shaft of a tracked vehicle) are shown as an example. An analysis of the correlation of two random variables (half-periods and half-ranges) according to empirical data has shown that the correlation exists and is significant for the observed number of points thus providing the basis for using the regression formula for an approximate choice of the frequency composition of the process. Moreover, the lower restrictions are imposed on the number of points (at least 5) in the half-period. Since the extrema of the initial and simulated processes coincide in accordance with the principle of the proposed simulation, the distribution of the amplitudes of complete cycles, as well as the results of schematization by other known methods are identical, therefore, the estimate of the durability by hypotheses based on a linear one is also identical. The validation of the method consists in consideration of the chain: 1) the initial continuous process; 2) the discrete process of extrema; 3) simulated continuous process according to the proposed method. Auxiliary distributions, such as distributions of maximum, minimum and average cycle values also coincide in accordance with the principle of modeling. The method is proposed to be used in analysis of the comparability of two competing approaches in assessing the loading in the problems of assessing durability, namely: those that use cycle-counting methods and methods based on the spectral density of processes. Since the spectral densities of the processes can differ due to an approximate choice of the frequencies on the basis of a regression formula, methods on their base can give estimates of the durability that differ from those obtained by schematization methods. To study this phenomenon, further computational experiments are required. The developed method can be very useful for the experiment design.

Development of the mathematical model for assessing the optimal measurement step when surveying the depth of the underground pipeline from the ground

2020 ◽  
Vol 10 (4) ◽  
pp. 364-371
Author(s):  
Ruslan V. Aginey ◽  
◽  
Rustem R. Islamov ◽  
Alexey A. Firstov ◽  
Elmira A. Mamedova ◽  
...  
Keyword(s):  
Mathematical Models ◽  
Survey Data ◽  
Ground Surface ◽  
Maximum Error ◽  
Large Error ◽  
Bending Stress ◽  
Buried Pipeline ◽  
Optimal Measurement ◽  
Pipeline Section ◽  
Bending Stresses

Existing methods for estimating the bending stresses of buried pipeline section based on the survey data for the depth of the axis of the pipeline from the ground surface are characterized by a large error between the real values of the bending stress and the values of the bending stress obtained from the calculation results based on the survey data. The purpose of this study is to improve the methodology for calculating the bending stresses of buried pipeline section based on the results of determining the depth of the axis of the pipeline from the ground surface, taking into account the design features of the pipeline and the used search equipment. Mathematical models are proposed that allow for the set value of the maximum error in determining bending stresses for a particular pipeline to choose the optimal measurement step before the survey, which will allow to reduce the error. Explanations are given on the choice of the maximum step of the study based on the strength characteristics of the pipeline. A calculation is provided that confirms the adequacy of the developed mathematical models and the possibility of their application in practice.

Pattern synthesis of array antennas in presence of conducting bodies of arbitrary shape

1997 ◽  
Vol 33 (18) ◽  
pp. 1512 ◽  
Author(s):  
L. Landesa ◽  
F. Obelleiro ◽  
J.L. Rodríguez ◽  
A.G. Pino
Keyword(s):  
Arbitrary Shape ◽  
Pattern Synthesis ◽  
Array Antennas ◽  
Conducting Bodies

The stokes translation of a particle of arbitrary shape along the axis of a circular cylinder

1966 ◽  
Vol 16 (1) ◽  
pp. 273-300 ◽  
Author(s):  
Richard M. Sonshine ◽  
Raymond G. Cox ◽  
Howard Brenner
Keyword(s):  
Circular Cylinder ◽  
Arbitrary Shape
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