Geometric Scaling of Plates Subjected to Mine Blast

2017 ◽  
Vol 67 (4) ◽  
pp. 454
Author(s):  
Dhiraj Prakash Badgujar ◽  
K. Srinivasan ◽  
P. Vasundhra ◽  
R. Murugesan ◽  
Lokavarapu Bhaskara Rao
Keyword(s):  
Surface Deformation ◽  
Plane Surface ◽  
Experimental Studies ◽  
Scale Model ◽  
Land Mine ◽  
Geometric Scaling ◽  
Out Of Plane ◽  
Blast Effect ◽  
Computationally Intensive ◽  
Proper Scaling

<p>In the design of AFVs, study of structures subjected to land mine blast is important. Generally, blast related experimental studies are very time consuming and costly. A simple first cut alternative is finite element modelling and analysis. Here, modelling of mine and simulating the blast effect involves large number of mesh elements, which makes the model computationally intensive and time consuming. Hence, instead of using full scale model for analysis, a suitable scaled down model would reduce analysis time and leads to a faster DOE studies. A proper scaling mechanism is to be evolved in order to get accurate results. Discusses about the scaling of plate subjected to mine blast using dimensional analysis approach. The out-of-plane surface deformation, including velocity fields during the blast loading are compared between the scaled and unscaled plate.</p>

A Real-Time DSPI System for Measuring Surface Deformation in Clamped Bolted Joints

2008 ◽  
Author(s):  
Aidong Meng ◽  
Sayed A. Nassar
Keyword(s):  
Real Time ◽  
Vibration Isolation ◽  
Surface Deformation ◽  
Plane Surface ◽  
Speckle Pattern ◽  
The Real ◽  
Time Deformation ◽  
Out Of Plane ◽  
Phase Data ◽  
Set Up

A Digital Speckle Pattern Interferometry (DSPI) system is developed for the real-time measuring and monitoring the out-of-plane surface deformation around tightened threaded fasteners that are used to clamp bolted assemblies. Spatial phase shifting is employed to quantitatively determine the distribution of phase data by introducing a spatial carrier fringe pattern to the speckle interferogram. This is achieved by leading the object and reference beams to two separate apertures. The configuration is also suitable for collecting the real-time deformation during bolt tightening. The experimental DSPI system is set-up with optical components on a vibration-isolation table. A Matlab software is developed for the image acquisition and phase data calculation, which yields the out-of-plane surface deformation caused by the bolt preload. An aluminum joint is used with an M12 steel fastener. For miniature screw application, however, a plastic joint is used for collecting data.

A Novel Optical Method for Real-Time Control of Bolt Tightening

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Aidong Meng ◽  
Sayed A. Nassar ◽  
Douglas Templeton
Keyword(s):  
Real Time ◽  
Vibration Isolation ◽  
Surface Deformation ◽  
Plane Surface ◽  
Speckle Pattern ◽  
Joint Surface ◽  
The Real ◽  
Bolt Preload ◽  
Out Of Plane ◽  
Phase Data

A digital speckle pattern interferometry (DSPI) system is developed for the real-time measurement and monitoring of the out-of-plane surface deformation around a preloaded bolt head or nut. The proposed system is specifically developed for the dynamic control of the bolt tightening process by continuously monitoring the out-of-plane joint surface deformation that will have been independently correlated to the bolt preload. Spatial phase shifting is employed to quantitatively determine the distribution of phase data by introducing a spatial carrier fringe pattern to the speckle interferogram. This is achieved by leading the object and reference beams through two separate apertures. The configuration is also suitable for collecting the real-time surface deformation during bolt tightening. The experimental DSPI system is set-up with optical components on a vibration-isolation table. A MATLAB software is developed for image acquisition and phase data calculations that yield the out-of-plane surface deformation caused by the bolt preload. The test fixture uses an M12 steel fastener and aluminum joint. For miniature screw applications, however, a plastic joint is used.

scholarly journals Characterization of Shear Horizontal Waves Using a 1D Laser Doppler Vibrometer

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2467
Author(s):  
Alaa Elhady ◽  
Eihab M. Abdel-Rahman
Keyword(s):  
Acoustic Waves ◽  
Surface Deformation ◽  
Plane Surface ◽  
Poisson Ratio ◽  
Surface Acoustic Waves ◽  
Laser Doppler Vibrometer ◽  
Element Analysis ◽  
Out Of Plane ◽  
Plane Displacement ◽  
Shear Horizontal

We developed a new technique for the detection of shear horizontal surface acoustic waves (SH-SAW) using a one-dimensional laser-based Doppler vibrometer. It measures the out-of-plane surface deformation at the fingertip of an interdigitated transducer (the boundary of the wave aperture) and uses it to estimate the instantaneous in-plane displacement field given the substrate Poisson ratio. It can also estimate the degree of surface confinement (wave decay rate). The proposed approach was first verified using finite element analysis (FEA) and demonstrated experimentally using a Bleustein–Gulyaev resonator.

Inverse Solution for Bolt Preload Using Surface Deformation

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
A. Zaki ◽  
S. A. Nassar ◽  
S. Kruk ◽  
M. Shillor
Keyword(s):  
Inverse Problem ◽  
Surface Deformation ◽  
Control Method ◽  
Plane Surface ◽  
Joint Surface ◽  
Problem Solution ◽  
Bolted Joint ◽  
Element Analysis ◽  
Out Of Plane ◽  
Axisymmetric Elasticity

In this paper, an inverse biharmonic axisymmetric elasticity problem is solved by invoking measured out-of-plane surface deformation values at discrete locations around a preloaded bolt head, in order to calculate the underhead contact stress and joint clamp load that would have caused that out-of-plane surface deformation. Solution of this type of inverse problem promises to improve the automation process of bolted joint system assembly, especially in critical and safety-related applications. For example, a real-time optically measured joint surface deformation can be utilized for automating process control of bolted joint assembly in a reliable fashion. This would be a significant reliability improvement as compared to the commonly used method in mass production using torque-only control method in which there is wide scatter in the torque–tension correlation due to the normal scatter in frictional variables. Finite element analysis (FEA) method is used to validate the inverse problem solution provided in this paper.

Inverse Solution for Bolt Preload Using Joint Surface Deformation

2013 ◽  
Author(s):  
Amro M. Zaki ◽  
Sayed A. Nassar ◽  
Meyer Shillor ◽  
Serge Kruk
Keyword(s):  
Inverse Problem ◽  
Surface Deformation ◽  
Control Method ◽  
Plane Surface ◽  
Joint Surface ◽  
Problem Solution ◽  
Bolted Joint ◽  
Element Analysis ◽  
Out Of Plane ◽  
Axisymmetric Elasticity

In this paper, an inverse bi-harmonic axisymmetric elasticity problem is solved by invoking measured out-of-plane surface deformation values at discrete locations around a preloaded bolt head, in order to calculate the under head contact stress and joint clamp load that would have caused that out-of-plane surface deformation. Solution of this type of inverse problem promises to improve the automation process of bolted joint system assembly, especially in critical and safety related applications. For example, a real-time optically measured joint surface deformation can be utilized for automating process control of bolted joint assembly in a reliable fashion. This would be a significant reliability improvement as compared to the commonly used method in mass production using torque-only control method in which there is wide scatter in the torque-tension correlation due to the normal scatter in frictional variables. Finite Element Analysis (FEA) method is used to validate the inverse problem solution provided in this paper.

Thermal and mechanical improvement of the air supply system of a turbocharged piston engine

2021 ◽  
Vol 14 (2) ◽  
pp. 108-114
Author(s):  
Y. M. Brodov ◽  
L. V. Plotnikov ◽  
K. O. Desyatov
Keyword(s):  
Heat Transfer ◽  
Experimental Studies ◽  
Local Heat Transfer ◽  
Supply System ◽  
Scale Model ◽  
Piston Engine ◽  
Intake System ◽  
Gas Dynamic ◽  
Air Supply ◽  
Air Flows

A method of thermomechanical improvement of pulsating air flows in the intake system of a turbocharged piston engine is described. The main objective of this study is to develop a method for suppressing the rate of heat transfer to improve the reliability of a piston turbocharged engine. A brief review of the literature on improving the reliability of piston engines is given. Scientific and technical results were obtained on the basis of experimental studies on a full-scale model of a piston engine. The hot-wire anemometer method was used to obtain gas-dynamic and heatexchange characteristics of gas flows. Laboratory stands and instrumentation facilities are described in the article. The data on gas dynamics and heat exchange of stationary and pulsating air flows in gas-dynamic systems of various configurations as applied to the air supply system of a turbocharged piston engine are presented. A method of thermomechanical improvement of flows in the intake system of an engine based on a honeycomb is proposed in order to stabilize the pulsating flow and suppress the intensity of heat transfer. Data were obtained on the air flow rate and the local heat transfer coefficient both in the exhaust duct of the turbocharger compressor (i.e., without a piston engine) and in the intake system of a supercharged engine. A comparative analysis of the data has been carried out. It was found that the installation of a leveling grid in the exhaust channel of a turbocharger leads to an intensification of heat transfer by an average of 9%. It was found that the presence of a leveling grid in the intake system of a piston engine causes the suppression of heat transfer within 15% in comparison with the baseline values. It is shown that the use of a modernized intake system in a diesel engine increases its probability of failure-free operation by 0.8%. The data obtained can be extended to other types and designs of air supply systems for heat engines.

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