Relaxation of Residual Stresses in and around Mechanical Fasteners Due to Fatigue Loading

2006 ◽  
pp. 153-158
Author(s):  
Matthew E. Fox ◽  
Philip J. Withers
Keyword(s):  
Residual Stresses ◽  
Fatigue Loading ◽  
Mechanical Fasteners

Relaxation of Residual Stresses in and around Mechanical Fasteners Due to Fatigue Loading

2006 ◽  
Vol 524-525 ◽  
pp. 153-158 ◽  
Author(s):  
Matthew E. Fox ◽  
Philip J. Withers
Keyword(s):  
Residual Stresses ◽  
Hoop Stress ◽  
Fatigue Cracks ◽  
Fatigue Loading ◽  
Far Field ◽  
Synchrotron Diffraction ◽  
Fastener Hole ◽  
Single Plate ◽  
Mechanical Fasteners ◽  
Hoop Stresses

The residual stresses around clearance-fit mechanical fasteners have been found to be similar to those around cold expanded holes where compressive hoop stresses close to the fastener hole are balanced by far-field tensile stresses. This compressive zone has been shown to prolong fatigue lifetimes around fastener holes. Constant amplitude fatigue loading was applied to single plate rivet specimens for varying numbers of cycles to investigate the redistribution of these stresses after fatiguing. Synchrotron diffraction was used to map the evolution of the residual stresses around the rivets. Little change in the hoop stress local to the rivets occurred until visible fatigue cracks were observed suggesting that relaxation of these stresses is due to the cracks rather than their cause.

The Effect of Several Finishing Processes on the Fatigue Resistance of Hole Surfaces

1989 ◽  
Vol 111 (1) ◽  
pp. 71-73 ◽  
Author(s):  
M. O. Lai ◽  
A. Y. C. Nee
Keyword(s):  
Surface Roughness ◽  
Plastic Deformation ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Fatigue Resistance ◽  
Radial Direction ◽  
Fatigue Loading ◽  
Steel Plates ◽  
Finishing Processes ◽  
Compressive Residual Stresses

This investigation examines the effects of different finishing processes on the fatigue life of premachined holes in Assab 760 steel plates. The finishing processes studied were reaming, ballizing, and emery polishing. A general decrease in fatigue life with increase in surface roughness is observed for all the processes employed. In comparing the different processes, for a constant surface roughness, polishing is generally found to give the longest fatigue life while ballizing, in spite of the greater compressive residual stresses induced on the surface of the finished hole, the shortest. The surprising phenomenon was found to be attributed to the amount of plastic deformation occurred before fatigue loading. For Assab 760 steel, a prestrain in the radial direction of less than about 2.5 percent appeared to reduce the fatigue resistance of the material.

Ultrasonic Measurement of Residual Stresses in Welded Elements of Ship Structure

2011 ◽  
Vol 70 ◽  
pp. 273-278 ◽  
Author(s):  
Yuri Kudryavtsev ◽  
Jacob Kleiman ◽  
Helena Polezhayeva
Keyword(s):  
Residual Stress ◽  
Cyclic Loading ◽  
Residual Stresses ◽  
Large Scale ◽  
Fatigue Loading ◽  
Residual Stress Distribution ◽  
Ultrasonic Measurement ◽  
Point Of View ◽  
Panel Analysis ◽  
Ship Structure

The objective of the study described in this paper is to identify the residual stress distribution and relaxation in standard welded specimens as well as in a large-scale welded panel imitating the critical, from the fatigue point of view, zones of ship structure. The residual stresses were measured after welding and in the process of fatigue loading of welded elements by the UltraMARS system that is based on using ultrasound. The measurements had shown that the maximum residual stresses near the welds (4-5 mm away from the weld) reach levels 290-320 MPa that are close to the yield strength of considered material both in welded specimens and in the large scale panel. Analysis of residual stress relaxation in the welded panel under the action of cyclic loading confirmed the fact that within the interval of applied stress ranges corresponding to the multi-cycle region of loading of the welded joints, the relaxation of residual stresses occurs mainly during the first cycle.

scholarly journals Ratcheting Simulation in a Titanium-Steel Bimetallic Plate Based on the Chaboche Hardening Model

2016 ◽  
Vol 10 (4) ◽  
pp. 265-270
Author(s):  
Aleksander Karolczuk
Keyword(s):  
Residual Stresses ◽  
Kinematic Hardening ◽  
Fatigue Loading ◽  
Experimental Results ◽  
Hardening Model ◽  
The Third ◽  
Hardening Rule ◽  
Bimetallic Plate

Abstract The paper presents the results of fatigue loading simulation applied to bimetallic model using the Chaboche kinematic hardening rule. Three cases of simulations were performed: (i) without residual stresses; (ii) considering residual stresses and (iii) considering asymmetrical geometry of bimetal, i.e. cross area reducing under tension period of loading. Experimental results exhibit the ratcheting phenomenon in titanium-steel bimetallic specimens. The observed ratcheting phenomenon could be explained by the third case of simulation which is supported by detection of microcracks in the vicinity of welded area.

scholarly journals Relaxation of Residual Stresses due to Fatigue Loading

1960 ◽  
Author(s):  
Jodean Morrow ◽  
A. S. Ross ◽  
G. M. Sinclair
Keyword(s):  
Residual Stresses ◽  
Fatigue Loading

scholarly journals The study of redistribution in residual stresses during fatigue crack growth

2021 ◽  
Vol 15 (4) ◽  
pp. 8565-8579
Author(s):  
Mohammad Noghabi ◽  
I. Sattari-far ◽  
H. Hosseini Toudeshky
Keyword(s):  
Fatigue Crack ◽  
Fatigue Crack Growth ◽  
Residual Stresses ◽  
Crack Growth ◽  
Crack Tip ◽  
Side Surface ◽  
Fatigue Loading ◽  
Compact Tension ◽  
Fracture Parameter ◽  
Residual Stress Field

Numerical and experimental study was conducted on fatigue crack growth (FCG) of metallic components to investigate the redistribution of mechanical residual stresses during FCG. To this end, the compact tension specimens of an aluminium alloy were used. In addition, mechanical residual stresses were introduced near the crack tip by applying compressive and tensile loads, followed by visually observing the side-surface of the specimens to estimate the crack growth length. In the numerical simulation, cyclic J-integral was used as the crack growth fracture parameter and a good agreement was observed between the numerical and experimental results. The results of the finite element method demonstrated a clear redistribution of mechanical residual stresses during FCG. After a few cycles, the residual stress field around the crack tip reached a lower magnitude value confined in a smaller zone, although this zone was stable during the remaining fatigue process. Finally, present study evaluated the effect of stress ratio, load amplitude, and initial residual stresses level on the redistribution of residual stresses. It was observed that the residual stresses are mainly released during the first steps of fatigue loading.

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