scholarly journals A Radial-In-Plane Sensitivity Interferometer with Divergent Illumination for Displacement Measurement

2020 ◽  
Vol 10 (3) ◽  
pp. 908
Author(s):  
Jorge R. Parra-Michel ◽  
David Gutiérrez-Hernández ◽  
Rafael Martínez-Peláez ◽  
Marco A. Escobar
Keyword(s):  
Mathematical Model ◽  
Radial Direction ◽  
Optical Axis ◽  
Displacement Measurement ◽  
Radial Deformation ◽  
Element Analysis ◽  
Phase Stepping ◽  
Maximum Contribution ◽  
Out Of Plane ◽  
Sensitivity Vector

An in-plane radial sensitivity interferometer that uses the divergent illumination for displacement measurement in the radial direction is presented. A description and mathematical model for calculating the sensitivity vector are also presented. The interferometer has two polarizing filters: a circular one and a linear one to implement the phase stepping technique. A measurement of the radial deformation by thermal expansion is performed over an aluminium plate in order to test the interferometer. The results indicate that the maximum contribution of the out-of-plane with respect to the radial-in-plane sensitivity vector is less than 3% and decreases by less than 1% when measurements are performed near the optical axis. The measurement is compared with the results obtained by a finite element analysis on a virtual specimen model.

scholarly journals Locally Corroded Stiffener Effect on Shear Buckling Behaviors of Web Panel in the Plate Girder

2015 ◽  
Vol 2015 ◽  
pp. 1-19 ◽  
Author(s):  
Jungwon Huh ◽  
In-Tae Kim ◽  
Jin-Hee Ahn
Keyword(s):  
Corrosion Damage ◽  
Element Analysis ◽  
Buckling Strength ◽  
Lower Shear ◽  
Out Of Plane ◽  
Shear Buckling ◽  
Buckling Failure ◽  
Plane Displacement ◽  
The Web ◽  
Plate Girder

The shear buckling failure and strength of a web panel stiffened by stiffeners with corrosion damage were examined according to the degree of corrosion of the stiffeners, using the finite element analysis method. For this purpose, a plate girder with a four-panel web girder stiffened by vertical and longitudinal stiffeners was selected, and its deformable behaviors and the principal stress distribution of the web panel at the shear buckling strength of the web were compared after their post-shear buckling behaviors, as well as their out-of-plane displacement, to evaluate the effect of the stiffener in the web panel on the shear buckling failure. Their critical shear buckling load and shear buckling strength were also examined. The FE analyses showed that their typical shear buckling failures were affected by the structural relationship between the web panel and each stiffener in the plate girder, to resist shear buckling of the web panel. Their critical shear buckling loads decreased from 82% to 59%, and their shear buckling strength decreased from 88% to 76%, due to the effect of corrosion of the stiffeners on their shear buckling behavior. Thus, especially in cases with over 40% corrosion damage of the vertical stiffener, they can have lower shear buckling strength than their design level.

Influence of Interference and Clamping on Fretting Fatigue in Single Rivet-Row Lap Joints

2000 ◽  
Vol 123 (4) ◽  
pp. 686-698 ◽  
Author(s):  
K. Iyer ◽  
C. A. Rubin ◽  
G. T. Hahn
Keyword(s):  
Crack Initiation ◽  
Three Dimensional ◽  
Fretting Fatigue ◽  
Cyclic Stress ◽  
Lap Joints ◽  
Element Analysis ◽  
Out Of Plane ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Fretting Damage

Primary fretting fatigue variables such as contact pressure, slip amplitude and bulk cyclic stresses, at and near the contact interface between the rivet shank and panel hole in a single rivet-row, 7075-T6 aluminum alloy lap joint are presented. Three-dimensional finite element analysis is applied to evaluate these and the effects of interference and clamping stresses on the values of the primary variables and other overall measures of fretting damage. Two rivet geometries, non-countersunk and countersunk, are considered. Comparison with previous evaluations of the fretting conditions in similar but two-dimensional connections indicates that out-of-plane movements and attending effects can have a significant impact on the fatigue life of riveted connections. Variations of the cyclic stress range and other proponents of crack initiation are found to peak at distinct locations along the hole-shank interface, making it possible to predict crack initiation locations and design for extended life.

scholarly journals Numerical Simulation of Diffusion Absorption Refrigerator

2021 ◽  
Vol 233 ◽  
pp. 01044
Author(s):  
Guoyan Zhang ◽  
Shengyong Liu ◽  
Jie Lu ◽  
Jiong Wang ◽  
Yongtao Ma
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Gas Phase ◽  
Radial Direction ◽  
Tube Length ◽  
Lifting Capacity ◽  
Fluent Software ◽  
Lower Temperature ◽  
Absorption Refrigerator ◽  
Diffusion Absorption

Based on Fluent software, a mathematical model of thermosyphon pump is established and numerical simulation is carried out to study the influence of riser tube length, tube diameter and immersion ratio on liquid lifting capacity and efficiency. The results showed that: the liquid lifting volume increased with the increase of immersion ratio, whereas the lifting efficiency showed a trend of increasing followed by decreasing. The highest lifting efficiency for a 340mm long, 6mm diameter riser achieved when the immersion ratio is 0.35. With the increasing of the height in riser, the velocity of the gas phase close to the wall in the thermosyphon pump was higher than the velocity along the radial direction. In order to enhance fluid interchange, corners of the refrigeration box were designed to be arc-shaped with a higher corner speed and lower temperature.

Predicting the Large Deflection Path of End-Loaded Tapered Cantilever Beams

2000 ◽  
Author(s):  
Matthew B. Parkinson ◽  
Gregory M. Roach ◽  
Larry L. Howell
Keyword(s):  
Mathematical Model ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Euler Equation ◽  
Large Deflection ◽  
Nonlinear Finite Element ◽  
Cantilever Beams ◽  
Element Analysis ◽  
Moments Of Inertia ◽  
Physical Testing

Abstract A simple (quadratic) mathematical model for predicting the deflection path of both non-tapered and continuously tapered cantilever beams loaded with a vertical end force is presented. It is based on the proposition that the path is a function of the ratio of the endpoints’ moments of inertia. The model is valid for both small and large (the tip makes a 70 degree angle with the horizontal) deflections. This was verified through physical testing, comparison to solution of the Bernoulli-Euler equation, and results obtained through nonlinear finite element analysis. Predicted endpoint deflections were found to be accurate within 1.8% of the actual deflection path for moment of inertia ratios varying from 1:1 to 1000:1.

Analysis of Three-Dimensional Clamped Single Edge Notched Tension (SENT) Specimens

2018 ◽  
Author(s):  
Zheng Liu ◽  
Xu Chen ◽  
Xin Wang
Keyword(s):  
Stress Intensity Factor ◽  
Stress Intensity ◽  
Intensity Factor ◽  
Crack Depth ◽  
Plate Thickness ◽  
Three Dimensional ◽  
Width Ratio ◽  
Element Analysis ◽  
Out Of Plane ◽  
T Stress

In the present paper, three-dimensional clamped SENT specimens, which is one of the most widely used low-constraint and less-conservative specimen, are analyzed by using a crack compliance analysis approach and extensive finite element analysis. Considering the test standard (BS8571) recommended specimen sizes, the daylight to width ratio, H/W, is 10.0, the relative crack depth, a/W, is varied by 0.2, 0.3, 0.4, 0.5 or 0.6 and the relative plate thickness, B/W, is chosen by 1.0, 2.0 or 4.0, respectively. Complete solutions of fracture mechanics parameters, including stress intensity factor (K), in-plane T-stress (T11) and out-of-plane T-stress (T33) are calculated, and the results obtained from above two methods have a good agreement. Moreover, the combination of the effects of a/W and B/W on the stress intensity factor K, T11 and T33 stress are thus illustrated.

scholarly journals Experimental and Numerical Analysis of Deformation in a Rotating RC Helicopter Blade

2020 ◽  
Vol 5 (3) ◽  
pp. 13
Author(s):  
Pedro J. Sousa ◽  
Francisco Barros ◽  
Paulo J. Tavares ◽  
Pedro M. G. P. Moreira
Keyword(s):  
Computational Models ◽  
Measurement Techniques ◽  
Image Correlation ◽  
Element Analysis ◽  
Helicopter Blade ◽  
Structure Interaction ◽  
Image Sensing ◽  
3D Digital Image Correlation ◽  
Out Of Plane ◽  
Computational Fluid Dynamics Cfd

Rotating structures are important and commonly used in the transportation and energy generation fields, where a better understanding of the deformations these structures endure is essential for both the design and maintenance phases. This work presents a novel image sensing methodology for measuring the displacements of rotating parts in operation due to dynamic loading. This methodology employs 3D digital image correlation combined with a custom stroboscopic lighting solution to achieve apparent stillness of the target while it rotates and then processes the acquired data to remove small imprecisions and align it to the rotor’s intrinsic coordinate system. It was applied to an RC helicopter, whose blade deformation was measured and compared with a computational model, using fluid–structure interaction between computational fluid dynamics (CFD) and finite element analysis (FEA). Using live measurement techniques, it was possible to obtain the actual behaviour of the blades, which can be used to validate and tune computational models. The proposed methodology complements the methods available in the literature, which were centred around relative out-of-plane displacements, by enabling the comparison of absolute out-of-plane and in-plane ones.

A Study Effect of Shooting 2 Balls in a Ball Swaging Process on Gram Load Parameter Using Finite Element Analysis

2014 ◽  
Vol 1061-1062 ◽  
pp. 421-426 ◽  
Author(s):  
Panupich Kheunkhieo ◽  
Kiatfa Tangchaichit
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Radial Direction ◽  
Base Plate ◽  
Element Model ◽  
Load Parameter ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Main Component

The purposes of this research are to explore the baseplate and actuator arm deformation which effect to the gram load which occur in the ball swaging process, the main component determining quality of assembly the head stack assembly with the actuator arm. By shooting a ball though the base plate, the component located on the head stack assembly, the base plate plastic deformation takes place and it in expand in radial direction. The base plate then adjoins with the actuator arm. Using the finite element method to reproduce the ball swaging process, we repeated to study effect of the swage press clamp and velocity. The study done by creating the three dimensionals finite element model to analyze and explain characteristics of the baseplate and actuator arm deformation which effect to gram load which effect to the ball swaging process.

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