Residual Stress Prediction Using Neural Network Approach

2014 ◽  
Vol 611 ◽  
pp. 436-440 ◽  
Author(s):  
František Menda ◽  
Marcel More ◽  
G.P. Cardona-Cuervo ◽  
F.J. Martinez-Tabares
Keyword(s):  
Neural Network ◽  
Residual Stress ◽  
Hole Drilling ◽  
Neural Network Approach ◽  
Stress Evaluation ◽  
New Approach ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Stress Prediction ◽  
Ring Core

Procedures for residual stress evaluation by using Ring-Core method have not been standardized. Most common techniques are derived from the ones used for similar semi-destructive hole-drilling method. The differences between research approaches can cause significant errors. New approach using neural network is proposed as a more adaptive way for residual stress evaluation than the commonly used methods.

Hole-Drilling Method for Residual Stress Measurement - Consideration of Elastic-Plastic Material Properties

2013 ◽  
Vol 768-769 ◽  
pp. 174-181 ◽  
Author(s):  
David von Mirbach
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Yield Stress ◽  
Material Properties ◽  
Plastic Material ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Elastic Plastic Material ◽  
Ring Core

Two commonly used mechanical methods for the determination of residual stresses are the hole-drilling method and the ring-core method, which can be regarded as semi-destructive. The most restricting limitation for the general applicability of both methods, according to the current state of science and technology, is the fact that the scope for relatively low residual stress under 60% of the yield stress is limited.This is a result of the notch effect of the hole or ring core, which leads to a plastification around and on the bottom of the hole and ring shaped groove already at stresses well below the yield stress of the material. The elastic evaluation of the resulting plastic strains leads consequently to an overestimation of the delineated residual stresses. In this paper the influence of elastic-plastic material properties no the specific calibration function for the hole-drilling method using the differential method is studied, and the method of adaptive calibration functions is presented.

Determination of the Necessary Geometric Parameters of the Specimen in Ring-Core Method

2013 ◽  
Vol 486 ◽  
pp. 90-95 ◽  
Author(s):  
František Menda ◽  
František Trebuňa ◽  
Patrik Šarga
Keyword(s):  
Residual Stress ◽  
Influential Factors ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Incremental Method ◽  
Core Method ◽  
Measuring Techniques ◽  
Drilling Method ◽  
Non Destructive ◽  
Ring Core

There are several measuring techniques for determining residual stress which can be divided according to the created damage in to the construction in non-destructive, semi-destructive and destructive ones. One of the most common is semi-destructive hole-drilling method. This paper deals about Ring-Core method which is based on the similar principles. Today, there is no standard for the Ring-Core method, thus it is important to consider various influential factors. One of them are the dimensions of specimen. Calibration coefficients are determined by finite element (FE) analysis using the commercial software Solidworks. These coefficients are used for residual stress evaluation by incremental method used in Ring-Core method. The influence of different specimen dimensions on the accuracy of the evaluated residual stresses is considered.

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 Four-Point Bending Tests to Study the So-Called Plasticity Effect on the Residual Stress Results Determined by the Hole-Drilling and Ring-Core Methods

2014 ◽  
Vol 996 ◽  
pp. 319-324
Author(s):  
David von Mirbach
Keyword(s):  
Residual Stress ◽  
Bending Test ◽  
Hole Drilling ◽  
Test Machine ◽  
Bending Tests ◽  
Hole Drilling Method ◽  
Four Point Bending ◽  
Drilling Method ◽  
Four Point Bending Test ◽  
Ring Core

The hole-drilling method (HDM) and ring core method (RCM) are limited to low residual stresses under 60% of the yield stress. This issue will experimentally analyze the method of adaptive calculation function, presented by the author on the ICRS9. With a four-point-bending test machine, a defined stress can be triggered between the middle bending. In this defined loading area, the strains in two load cases with the HDM and the RCM configuration were measured. With these measured strains the residual stress calculation will be analysed.

Residual Stress Evaluation by the Hole-Drilling Method With Off-Center Hole: An Extension of the Integral Method

1997 ◽  
Vol 119 (1) ◽  
pp. 79-85 ◽  
Author(s):  
Dario Vangi
Keyword(s):  
Residual Stress ◽  
Integral Method ◽  
Radial Direction ◽  
Hole Drilling ◽  
Strain Gages ◽  
Stress Evaluation ◽  
Hole Drilling Method ◽  
Incremental Hole Drilling ◽  
Drilling Method ◽  
Stress Variations

With the incremental hole-drilling method, it is possible to evaluate residual stress variations with depth, acquiring strain values for each step by strain gages. These data can be processed by the integral method. Usually strain gages are not spaced equidistant from the hole center nor arranged in the radial direction, due to practical difficulties in drilling a centered hole. In this study we present a development of the integral method for evaluating stress variations with depth in the specimen for eccentric blind hole cases. The results can be extended and adopted for use with a non-conventional strain gage array.

Artificial neural network for correction of effects of plasticity in equibiaxial residual stress profiles measured by hole drilling

2017 ◽  
Vol 52 (3) ◽  
pp. 137-151 ◽  
Author(s):  
Sergey Chupakhin ◽  
Nikolai Kashaev ◽  
Benjamin Klusemann ◽  
Norbert Huber
Keyword(s):  
Neural Network ◽  
Residual Stress ◽  
Inverse Problem ◽  
Artificial Neural Network ◽  
Yield Strength ◽  
Residual Stresses ◽  
Integral Method ◽  
Hole Drilling ◽  
Hole Drilling Method ◽  
Drilling Method

The hole drilling method is a widely known technique for the determination of non-uniform residual stresses in metallic structures by measuring strain relaxations at the material surface caused through the stress redistribution during drilling of the hole. The integral method is a popular procedure for solving the inverse problem of determining the residual stresses from the measured surface strain. It assumes that the residual stress can be approximated by step-wise constant values, and the material behaves elastically so that the superposition principle can be applied. Required calibration data are obtained from finite element simulations, assuming linear elastic material behavior. That limits the method to the measurement of residual stresses well below the yield strength. There is a lack of research regarding effects caused by residual stresses approaching the yield strength and high through-thickness stress gradients as well as the correction of the resulting errors. However, such high residual stresses are often introduced in various materials by processes such as laser shock peening, for example, to obtain life extension of safety relevant components. The aim of this work is to investigate the limitations of the hole drilling method related to the effects of plasticity and to develop an applicable and efficient method for stress correction, capable of covering a wide range of stress levels. For this reason, an axisymmetric model was used for simulating the hole drilling process in ABAQUS involving plasticity. Afterward, the integral method was applied to the relaxation strain data for determining the equibiaxial stress field. An artificial neural network has been used for solving the inverse problem of stress profile correction. Finally, AA2024-T3 specimens were laser peened and the measured stress fields were corrected by means of the trained network. To quantify the stress overestimation in the hole drilling measurement, an error evaluation has been conducted.

Sign in / Sign up

Export Citation Format

Share Document