scholarly journals Residual Stress Measurements on a Metal Matrix Composite Using the Contour Method with Brittle Fracture

2014 ◽  
Vol 996 ◽  
pp. 349-354 ◽  
Author(s):  
Jeferson Araujo de Oliveira ◽  
Michael E. Fitzpatrick ◽  
Jan Kowal
Keyword(s):  
Residual Stress ◽  
Fatigue Crack ◽  
Brittle Failure ◽  
Metal Matrix ◽  
Crack Surface ◽  
Contour Method ◽  
Wire Edm ◽  
Stress Measurements ◽  
Fatigue And Fracture ◽  
Cut Surface

In this work we evaluate the application of the contour method to fatigue and fracture surfaces. Residual stress measurements were made on quenched and aged AA2124-SiCp composite using neutron diffraction, the contour method with wire EDM, and the contour method on a fatigue crack surface including brittle failure. The contour method successfully measured residual stresses from a wire electro-discharge cut surface, but the fracture method results suggest that residual stress information is lost due to plasticity during fatigue crack growth.

scholarly journals Experimental study of the effects of wire EDM on the characteristics of ferritic steel, at a micro-scale on the contour cut surface

2018 ◽  
Vol 115 (4) ◽  
pp. 413
Author(s):  
Nida Naveed
Keyword(s):  
Residual Stress ◽  
Stress Measurement ◽  
Surface Characteristics ◽  
Surface Damage ◽  
Cutting Process ◽  
Contour Method ◽  
X Ray Diffraction ◽  
Micro Scale ◽  
Macro Scale ◽  
Cut Surface

This study, on a micro-scale, of the WEDM cut surfaces of specimens to which the contour method of residual stress measurement is being applied provides detailed information about the effects of the cutting process on the surface quality. This is defined by a combination of several parameters: variation in surface contour profile, sub-surface damage and surface texture. Measurements were taken at the start, the middle and at the end of the cut. This study shows that during WEDM cutting, a thin layer, extending to a depth of a few micrometres below the surface of the cut, is transformed. This layer is known as the recast layer. Using controlled-depth etching and X-ray diffraction, it is shown that this induces an additional tensile residual stress, parallel to the plane of the cut surface. The WEDM cut surface and sub-surface characteristics are also shown to vary along the length of the cut. Moreover, these micro-scale changes were compared with macro-scale residual stress results and provides an indication of the point at which the changes occurred by cutting process can be significantly relative to the macro-scale residual stress in a specimen.

An Efficient Modelling Approach for Predicting Residual Stress in Power-Beam Welds

2019 ◽  
Author(s):  
Graeme Horne ◽  
Danny Thomas ◽  
Andrew Collett ◽  
Andrew Clay ◽  
Martin Cott ◽  
...  
Keyword(s):  
Residual Stress ◽  
Structural Integrity ◽  
Welding Residual Stress ◽  
Contour Method ◽  
Element Analysis ◽  
Stress Measurements ◽  
316L Austenitic Stainless Steel ◽  
Important Input ◽  
Integrity Assessments ◽  
Modelling Approach

Abstract The prediction of welding residual stress in components is often an important input to structural integrity assessments. An efficient modelling approach was developed for predicting residual stress in power-beam welds, including validation against residual stress measurements. Specifically, sequentially coupled thermo-mechanical finite element analysis was conducted using a simplified heat source that was tuned to the observed fusion zone from a weld macrograph and thermocouple data for a series of electron beam welds in 316L austenitic stainless steel with a variety of geometries. The predicted residual stresses were compared with contour method and neutron diffraction residual stress measurements.

Simulation of residual stress using thermomechanical analysis on wire EDM cut surface

2019 ◽  
Vol 19 ◽  
pp. 462-467 ◽  
Author(s):  
Sujay Bhattacharya ◽  
Abhishek Mishra ◽  
Tarvinder Singh ◽  
Srijit Bandyopadhyay ◽  
Santhosh Kumar ◽  
...  
Keyword(s):  
Residual Stress ◽  
Thermomechanical Analysis ◽  
Wire Edm ◽  
Cut Surface

Residual Stress Measurements Revealing Weld Bead Start and Stop Effects in Single and Multi-Pass Weld-Runs

2005 ◽  
Author(s):  
Peter J. Bouchard ◽  
Javier R. Santisteban ◽  
Lyndon Edwards ◽  
Mark Turski ◽  
Jon James ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Weld Bead ◽  
Contour Method ◽  
Stress And Strain ◽  
Outer Diameter ◽  
End Effects ◽  
Stress Measurements ◽  
Stress Variations ◽  
Welding Direction

This paper describes transverse residual stress and strain measurements aimed at quantifying end effects in single and multi-pass weld-runs. Two test specimens are examined: a 60 mm long weld bead deposited on the surface of a 180 mm × 120 mm × 17 mm thick stainless steel plate, and a 62° arc-length multi-pass repair weld in a 432 mm outer diameter, 19.6 mm thick stainless steel pipe girth weld. The residual stress measurements were made by employing the relatively new Contour method and by neutron diffraction using ENGIN-X, the engineering spectrometer at the ISIS facility of the Rutherford Appleton Laboratory (UK). The measured underlying transverse residual stress levels are observed to be essentially uniform directly beneath the weld bead in the plate specimen and in the heat affected zone beneath the capping passes moving from mid-length towards the stop-end of the pipe repair. However, results from both test components demonstrate the existence of short-range concentrations of transverse residual stress along the welding direction owing to individual weld capping bead start and stop effects. Such short length-scale stress variations must be allowed for when interpreting residual stress measurements from line-scans. The experimental work also demonstrates the importance of knowing the expected stress or strain distribution prior to choosing measurement lines for detailed study. The Contour measurement method and neutron strain scanning are powerful tools for mapping residual stress and strain fields.

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