Prediction of Residual Stress Relaxation During Fatigue Loading and Taking Residual Stresses in a Multiaxial Fatigue Criteria Into Account

1989 ◽  
pp. 784-790
Author(s):  
J. Lu ◽  
J. F. Flavenot
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Residual Stresses ◽  
Fatigue Loading ◽  
Multiaxial Fatigue ◽  
Residual Stress Relaxation

Relaxation of Residual Stresses in Bearing Rings Based on the Optimal Geometric Setup of Equipment for Centerless Running

2019 ◽  
Vol 973 ◽  
pp. 183-188
Author(s):  
Albert V. Korolev ◽  
Andrei F. Balayev ◽  
Boris M. Iznairov
Keyword(s):  
Mathematical Model ◽  
Residual Stress ◽  
Stress Relaxation ◽  
Residual Stresses ◽  
Elastic Strain ◽  
New Approach ◽  
Technological Method ◽  
Residual Stress Relaxation ◽  
Bearing Rings

This paper discusses the technological method of residual stress relaxation of bearing rings by centerless running with cylindrical rolls. Described a new approach to relieve residual stresses by centerless running of elastically-deforming rolls on the basis of the geometrical setup of the equipment. It was found that geometrical setup of the equipment influences an elastic strain of parts and the degree of residual stress relaxation. We obtained a mathematical model for calculation of setup parameters to ensure the required variation value of elastic strain of the part. The results of experiments confirm the influence of the geometric setup on the magnitude of residual stress relaxation.

Polycrystal Plasticity Modeling of Cyclic Residual Stress Relaxation in Shot Peened Martensitic Gear Steel

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
Rajesh Prasannavenkatesan ◽  
David L. McDowell
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Residual Stresses ◽  
Shot Peening ◽  
Cyclic Plasticity ◽  
Residual Stress Field ◽  
Residual Stress Relaxation ◽  
Gear Steel ◽  
Polycrystal Plasticity ◽  
Compressive Residual Stresses

Using a three-dimensional crystal plasticity model for cyclic deformation of lath martensitic steel, a simplified scheme is adopted to simulate the effects of shot peening on inducing initial compressive residual stresses. The model is utilized to investigate the subsequent cyclic relaxation of compressive residual stresses in shot peened lath martensitic gear steel in the high cycle fatigue (HCF) regime. A strategy is identified to model both shot peening and cyclic loading processes for polycrystalline ensembles. The relaxation of residual stress field during cyclic bending is analyzed for strain ratios Rε=0 and −1 for multiple realizations of polycrystalline microstructure. Cyclic microplasticity in favorably oriented martensite grains is the primary driver for the relaxation of residual stresses in HCF. For the case of Rε=−1, the cyclic plasticity occurs throughout the microstructure (macroplasticity) during the first loading cycle, resulting in substantial relaxation of compressive residual stresses at the surface and certain subsurface depths. The initial magnitude of residual stress is observed to influence the degree (percentage) of relaxation. Describing the differential intergranular yielding is necessary to capture the experimentally observed residual stress relaxation trends.

scholarly journals Effects of Conventional and Severe Shot Peening on Residual Stress and Fatigue Strength of Steel AISI 1060 and Residual Stress Relaxation Due to Fatigue Loading: Experimental and Numerical Simulation

2020 ◽  
Author(s):  
Erfan Maleki ◽  
Gholam Hossein Farrahi ◽  
Kazem Reza Kashyzadeh ◽  
Okan Unal ◽  
Mario Gugaliano ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Numerical Simulation ◽  
Residual Stress ◽  
Stress Relaxation ◽  
Shot Peening ◽  
Fatigue Behavior ◽  
Fatigue Loading ◽  
Experimental Investigations ◽  
Residual Stress Relaxation ◽  
Severe Shot Peening

Abstract This study investigates and compares the effects of different shot peening treatments including conventional and severe shot peening on microstructure, mechanical properties, fatigue behavior, and residual stress relaxation of AISI 1060 steel. Shot peening treatments were applied with two Almen intensities of 17 and 21 A and a wide ranges of coverage (100%–1500%). Various microstructural observations were carried out to analyze the evolution of microstructure. Microhardness, residual stress and surface roughness measurements and also axial fatigue test were performed. Moreover, the extent of the residual stress relaxation during cyclic loading was investigated by means of XRD measurements. Furthermore, numerical simulation of residual stress relaxation due to fatigue loading was carried out and validated against experimental investigations. The comparison indicated a good agreement for the surface residual stress relaxation up to 100 cycles. The experimental results indicated the efficiency of severe shot peening processes in obtaining nanostructured surface layer and achieving superior mechanical properties and fatigue behavior. Also, residual stress measurements revealed that stress relaxation started with a high rate at the initial stages of loading and gradually increased at higher number of cycles which was lower in the case of severely shot peened samples compared to the conventionally treated ones. Graphic Abstract

Surface Yield Strength Gradient versus Residual Stress Relaxation of 7075 Aluminum Alloy

2010 ◽  
Vol 160-162 ◽  
pp. 241-246 ◽  
Author(s):  
Yong Hui Hu ◽  
Yun Xin Wu ◽  
Guang Yu Wang ◽  
Jun Kang Guo
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Stress Relaxation ◽  
Yield Strength ◽  
Residual Stresses ◽  
Shot Peening ◽  
Fatigue Property ◽  
7075 Aluminum Alloy ◽  
Residual Stress Relaxation ◽  
Stress Coefficient

Different distributed residual stresses were introduced by quenching and two shot-peening treatments on 7075 aluminum alloy. The residual stress distributions and micro-hardness profiles in surface layers were measured. Pre-stress coefficient characterizing contribution of local residual stresses to local yield strength is introduced to analyze residual stress relaxation under cyclic loading. Load testing shows that re-distribution of residual stresses and proportional decrease of the pre-stress coefficient would occur in the non-uniform structural residual stresses introduced by quenching, while great stress relaxation and non-linear decrease of the pre-stress coefficient would occur in the uniform surface residual stresses introduced by shot-peening. Additionally, advantages of surface compressive residual stress and micro yield strength on anti-fatigue property and on restraining initiation and propagation of surface micro cracks should be considered in the usually conservative engineering design.

Numerical Simulation of Tensile Residual Stresses in SWCNT-Reinforced Polymer Composites

2021 ◽  
Vol 36 (1) ◽  
pp. 13-25
Author(s):  
M. R. Soleimany ◽  
M. Jamal-Omidi ◽  
S. M. Nabavi ◽  
M. Tavakolian
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Residual Stresses ◽  
Polymer Matrix ◽  
Van Der Waals Interactions ◽  
Fe Modelling ◽  
Perfectly Plastic ◽  
Residual Stress Relaxation ◽  
Mechanical Tensile ◽  
Elastic Perfectly Plastic

Abstract The residual stresses play a significant role in the mechanical properties and strengthening capability of nanocomposites. The present research aims to numerically investigate the residual stress relaxation in nanotube-reinforced polymers in response to mechanical tensile loading. The systems under study consist of the armchair and zigzag single-walled carbon nanotubes (SWCNT) embedded in a polymer matrix. The nanotubes and polymer matrix are assumed to be bonded by van der Waals interactions based on the Lennard-Jones (L-J) potential at the interface. The interactions between carbon atoms in the nanotube and nodes in the polymer matrix are modelled by equivalent springs. In order to evaluate the analysis of elastic-perfectly plastic using finite element (FE) modelling, first, relaxation of the plastic residual stresses on steel hemisphere in contact with a rigid flat surface was examined in a loading-unloading cycle and verified with available data. Afterwards, the residual stress relaxation in nanotubes with different space-frame structures was computed due to displacement-controlled loading. Finally, the stress state and the plastic residual stresses in the nanocomposite for different carbon nanotube content were analyzed and discussed during loading and unloading. Regarding the effect of tensile stress, it was revealed that nanotube structures have significant effects on the residual stresses created in the nanocomposite.

Residual Stresses Relaxation Caused by Pulsed Electric Current

2010 ◽  
Vol 638-642 ◽  
pp. 2429-2433 ◽  
Author(s):  
Gennadiy Stepanov ◽  
Anatoli Babutsky ◽  
Leopold Kruszka
Keyword(s):  
Residual Stress ◽  
Stress Relaxation ◽  
Residual Stresses ◽  
Electric Current ◽  
High Density ◽  
Composite Joint ◽  
Residual Stress Relaxation ◽  
Pulsed Electric Current ◽  
Copper Composite

The results of investigations of the influence of the treatment based on a direct passage of pulsed electric current of high density through the simple parts with a copper-composite joint, coatings and a grinded surface causing residual stress relaxation and redistribution of the stresses are presented in the paper.

scholarly journals Analysing the Fatigue Behaviour and Residual Stress Relaxation of Gradient Nano-Structured 316L Steel Subjected to the Shot Peening via Deep Learning Approach

2021 ◽  
Author(s):  
Erfan Maleki ◽  
Okan Unal ◽  
Mario Guagliano ◽  
Sara Bagherifard
Keyword(s):  
Mechanical Properties ◽  
Residual Stress ◽  
Deep Learning ◽  
Stress Relaxation ◽  
Shot Peening ◽  
Fatigue Behavior ◽  
Fatigue Crack Initiation ◽  
Fatigue Loading ◽  
Learning Approach ◽  
Residual Stress Relaxation

AbstractIn this study, the effect of kinetic energy of the shot peening process on microstructure, mechanical properties, residual stress, fatigue behavior and residual stress relaxation under fatigue loading of AISI 316L stainless steel were investigated to figure out the mechanisms of fatigue crack initiation and failure. Varieties of experiments were applied to obtain the results including microstructural observations, measurements of hardness, roughness, induced residual stress and residual stress relaxation as well as axial fatigue test. Then deep learning approach through neural networks was used for modelling of mechanical properties and fatigue behavior of shot peened material. Comprehensive parametric analyses were performed to survey the effects of different key parameters. Afterward, according to the results of neural network analysis, further experiments were performed to optimize and experimentally validate the desirable parameters. Based on the obtained results the favorable range of shot peening coverage regarding improved mechanical properties and fatigue behavior was identified as no more than 1750% considering Almen intensity of 21 A (0.001 inch). Graphic abstract

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