Inverse Solution for Bolt Preload Using Joint Surface Deformation

Author(s):  
Amro M. Zaki ◽  
Sayed A. Nassar ◽  
Meyer Shillor ◽  
Serge Kruk

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.

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
A. Zaki ◽  
S. A. Nassar ◽  
S. Kruk ◽  
M. Shillor

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.


2011 ◽  
Vol 133 (6) ◽  
Author(s):  
Aidong Meng ◽  
Sayed A. Nassar ◽  
Douglas Templeton

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.


Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2467
Author(s):  
Alaa Elhady ◽  
Eihab M. Abdel-Rahman

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.


Author(s):  
Aidong Meng ◽  
Sayed A. Nassar

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.


2013 ◽  
Vol 397-400 ◽  
pp. 198-201
Author(s):  
Wan Yu Li ◽  
Cong Lu ◽  
Zhuo Yang

In order to evaluate the assembly precision of the CNC machine tools influenced by the joint surface characteristics effectively, a method is proposed in this paper. Finite element analysis is used to obtain joint surface deformation data, and then a second-order response surface model is established as a surrogate model to express the function of joint surface static characteristics and deformation. The error propagation in assembly sequence is obtained, so that the assembly precision of CNC machine tools can be evaluated effectively.


2017 ◽  
Vol 67 (4) ◽  
pp. 454
Author(s):  
Dhiraj Prakash Badgujar ◽  
K. Srinivasan ◽  
P. Vasundhra ◽  
R. Murugesan ◽  
Lokavarapu Bhaskara Rao

<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>


Author(s):  
Cong Lu ◽  
Song-Ling Wang

This paper proposes an approach to evaluating the product assembly precision in different assembly sequences, considering the effect of joint surface deformation. Three assembly variation sources, including manufacturing variation, assembly clearance and joint surface deformation, which have effect on the final assembly precision are analyzed. Based on finite element analysis, a hybrid genetic algorithm and back-propagation neural network model is built to predict the assembly variations, which are caused by the joint surface deformation under different assembly conditions and different parameters of the joint surface. An assembly variation propagation model is built, and a product assembly precision evaluation approach is proposed to identify the feasible assembly sequences, and the optimal assembly sequence considering the effect of the joint surface deformation. Finally, a case study is given to verify the proposed approach.


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