scholarly journals Application of 3D DIC-Assisted Residual Stress Measurements for Friction Stir Welding Weld from Ultrafine-Grained Aluminum

2020 ◽  
Vol 52 (1) ◽  
pp. 20-25
Author(s):  
Tomasz Brynk ◽  
Marta Orłowska ◽  
Małgorzata Lewandowska
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Image Correlation ◽  
Hole Drilling ◽  
Friction Stir ◽  
Hole Drilling Method ◽  
3D Digital Image Correlation ◽  
Novel Approach ◽  
Ultrafine Grained

AbstractThe present study describes a novel approach applying 3D digital image correlation to a hole drilling method to measure residual stresses. Measurements were performed on a friction stir-welded joint made of ultrafine-grained aluminum. The results show that severe plastic deformation did not significantly change the residual stresses, while in the weld’s stir zone they increased to 100 to 200 MPa. The obtained results demonstrate the reliability of the applied residual stress measurement method.

Inverse Hole-Drilling Method for Residual Stress Investigation

2016 ◽  
Vol 827 ◽  
pp. 117-120
Author(s):  
Jaroslav Vaclavik ◽  
Stanislav Holy ◽  
Jiří Jankovec ◽  
Petr Jaros ◽  
Otakar Weinberg
Keyword(s):  
Residual Stress ◽  
Numerical Modeling ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Hole Drilling ◽  
Back Side ◽  
Stress Evaluation ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Strain Gauge Rosette

The method for residual stress measurement using through the hole drilling and investigation of the residual stresses relief with the help of incremental layers removing is presented. Drilling the rosette-hole from the opposite side – the inverse layers removing – have to be used for evaluation of residual stress near the back side of the object wall in cases when this surface is inaccessible for any hole-drilling instrument. The strain gauge rosette is installed on the opposite side of the drilled wall and a new mechanical task of incremental layers removal must be solved. The calibration constants for residual stress evaluation of HBM RY21 type rosette for this case were derived using numerical modeling by FEA and its experimental verification.

scholarly journals Effect of Residual Stress on the Mechanical Properties of FSW Joints with SUS409L

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Yeong-Seok Lim ◽  
Sang-Hyuk Kim ◽  
Kwang-Jin Lee
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Residual Stresses ◽  
Welded Joints ◽  
Stress Measurement ◽  
Charpy Impact ◽  
Stir Zone ◽  
Hole Drilling ◽  
Friction Stir ◽  
Compressive Residual Stresses

This study was performed to investigate both the residual stress distribution and the effect of the residual stress formed at the welding region on the mechanical properties of the friction stir welded joints with 409L stainless steel sheets. Residual stress measurement with hole-drilling method; mechanical property evaluation including tensile test, Charpy impact test, and fatigue test; and microstructure observation were conducted. It has got no residual stresses to speak of at the center region of the stir zone because the stored stresses are released in the process of the dynamic recrystallization, while a small quantity of compressive residual stresses is formed at the surface region of the stir zone because of strong compression reaction by the tool shoulder. A considerable amount of compressive residual stresses is formed at the thermomechanical affected zone because of the synergy between the thermal expansion due to the heat conduction from the stir zone and mechanical compression by the tool. The formation of residual stresses shows a similar tendency between the advancing side and the retreating side. Both the mitigation of residual stress in the stir zone and the formation of compressive residual stress in the thermomechanical affected zone contribute to the improvement of the mechanical properties of the friction stir welded joints.

scholarly journals DIC-hole drilling method for in-situ residual stress measurement

2019 ◽  
Vol 275 ◽  
pp. 02004 ◽  
Author(s):  
Yang Peng ◽  
Jun Zhao ◽  
Lan-shu Chen ◽  
Jun Dong
Keyword(s):  
Residual Stress ◽  
Displacement Field ◽  
Stress Measurement ◽  
Steel Structures ◽  
Image Correlation ◽  
Residual Stress Measurement ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Drilling Method

Residual stress measurement carries an important significance in ensuring safety and reliability of steel structures. In order to simplify the measurement procedure and enhance flexibility of the conventional hole drilling method to adopt in in-situ residual stress measurement, digital image correlation (DIC) is applied to measure the displacement field caused by the localized stress relief associated due to hole drilling. It is referred to as DIC-hole drilling method. The residual stress theoretical expressions of the DIC-hole drilling method are discussed. The requirements of drilling device, camera and lens are determined by accounting for the accuracy of the in-situ residual stress measurement. A benchmark experiment by using steel beam specimens is developed to verify the feasibility and reliability of DIC-hole drilling method. Test data are compared with theoretical calculations and FEM results. The comparison indicates the DIC-hole drilling method has enough accuracy for the in-situ residual stress measurement. The displacement field in the regions centred at 2 to 2.5 times drilling hole radius far from the hole is proposed for the accurate residual stress measurement.

Measurement of Residual Stresses Near the Surface Using the Crack Compliance Method

1991 ◽  
Vol 113 (2) ◽  
pp. 199-204 ◽  
Author(s):  
W. Cheng ◽  
I. Finnie ◽  
O¨. Vardar
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Computational Model ◽  
Strain Measurement ◽  
Stress Measurement ◽  
Residual Stress Measurement ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Drilling Method

The use of thin cuts for residual stress measurement is referred to as the crack compliance method. A computational model is presented for the determination of normal and shear residual stresses near the surface by introducing shallow cuts. The optimum regions for strain measurement are obtained. This method is shown to be considerably more sensitive than the conventional hole drilling method and is capable of measuring residual stresses which vary with depth below the surface.

Simulation and Measurement of Residual Stresses in a Stainless Steel Ring Welded Circular Disc

2012 ◽  
Author(s):  
Gang Zheng ◽  
Sayeed Hossain ◽  
Mike Smith ◽  
David Smith
Keyword(s):  
Residual Stress ◽  
Neutron Diffraction ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Circular Disc ◽  
Hole Drilling ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Hole Drilling Method ◽  
Drilling Method

Residual stresses were predicted and measured in a circular disc containing a partial ring weld. This study first created an axisymmetric finite element model so that the process of introducing the ring weld was simulated using thermal and mechanical modelling. The resulting residual stresses were then mapped onto a 3D model which included the necessary mesh and boundary conditions to simulate the process of residual stress measurement using the deep hole drilling method. Then an experimental programme of residual stress measurement using the deep hole drilling method and the neutron diffraction technique was conducted on the welded circular disc. The results from the deep hole drilling measurements matched well with the neutron diffraction results on the original stress field in the ring weld. While comparison between measurements and predicted residual stresses show that predicted hoop stresses are slightly higher than measured, there is in general a fair comparison between measured and predicted residual stress.

Residual Stress Measurements in an Autofrettage Tube Using Hole Drilling Method

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Hamid Jahed ◽  
Mohammad Reza Faritus ◽  
Zeinab Jahed
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Hoop Stress ◽  
Test Method ◽  
Test Material ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Ring Sample ◽  
Drilling Method ◽  
American Society

Relieved strains due to drilling hole in a ring sample cut from an autofrettage cylinder are measured. Measured strains are then transformed to residual stresses using calibration constants and mathematical relations of elasticity based on ASTM standard recommendations (American Society for Testing and Materials, ASTM E 837-08, 2008, “Standard Test Method for Determining Residual Stresses by the Hole-Drilling Strain-Gage Method,” American Society for Testing and Materials). The hydraulic autofrettage is pressurizing a closed-end long cylinder beyond its elastic limits and subsequently removing the pressure. In contrast to three-dimensional stress state in the autofrettage tube, the stress measurement in hole drilling method is performed on a traction free surface formed from cutting the ring sample. The process of cutting the ring sample from a long autofrettaged tube is simulated using finite element method (FEM) and the redistribution of the residual stress due to the cut is discussed. Hence, transformation of the hole drilling measurements on the ring slice to the autofrettage residual stresses is revealed. The residual stresses are also predicted by variable material properties (VMP) method (Jahed, H., and Dubey, R. N., 1997, “An Axisymmetric Method of Elastic-Plastic Analysis Capable of Predicting Residual Stress Field,” Trans. ASME J. Pressure Vessel Technol., 119, pp. 264–273) using real loading and unloading behavior of the test material. Prediction results for residual hoop stress agree very well with the measurements. However, radial stress predictions are less than measured values particularly in the middle of the ring. To remove the discrepancy in radial residual stresses, the measured residual hoop stress that shows a self-balanced distribution was taken as the basis for calculating residual radial stresses using field equations of elasticity. The obtained residual stresses were improved a lot and were in good agreement with the VMP solution.

scholarly journals The Effect of Specimen Size on Residual Stresses in Friction Stir Welded Aluminum Components

2014 ◽  
Vol 996 ◽  
pp. 445-450 ◽  
Author(s):  
Wulf Pfeiffer ◽  
Eduard Reisacher ◽  
Michael Windisch ◽  
Markus Kahnert
Keyword(s):  
Residual Stresses ◽  
Specimen Size ◽  
Hole Drilling ◽  
X Ray Diffraction ◽  
X Ray ◽  
Friction Stir ◽  
Metal Parts ◽  
Hole Drilling Method ◽  
Incremental Hole Drilling ◽  
Drilling Method

Friction stir welding (FSW) is a well-known technique which allows joining of metal parts without severe distortion. Because FSW involves less heat input relative to conventional welding, it may be assumed that cutting specimens from larger friction stir welded components results in a negligible redistribution of residual stresses. The aim of the investigations was to verify these assumptions for a welded aluminum plate and a circumferentially-welded aluminum cylinder. Strain gage measurements, X-ray diffraction and the incremental hole drilling method were used.

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