scholarly journals Estimation of Residual Stress Field Uniformity when Using the Ring-Core Method

2014 ◽  
Vol 996 ◽  
pp. 325-330 ◽  
Author(s):  
František Menda ◽  
Patrik Šarga ◽  
František Trebuňa
Keyword(s):  
Complex Analysis ◽  
Hole Drilling ◽  
Data Sets ◽  
Residual Stress Field ◽  
Hole Drilling Method ◽  
Core Method ◽  
Uniformity Test ◽  
Drilling Method ◽  
Field Uniformity ◽  
Ring Core

The evaluation of residual stresses using Ring-Core method requires complex analysis of the acquired strain values. The development is based on ASTM Standard E837-08 for hole-drilling method, but the specific approach for Ring-Core is needed. The input data sets obtained from strain gage rosette are categorized by proposed uniformity test. The influence of geometric parameters of the specimen on this test and subsequently on the both uniform and nonuniform calculations is considered.

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.

Analysis of Differential Method Used for the Evaluation of Uniform Residual Stresses by the Ring-Core Method

2015 ◽  
Vol 732 ◽  
pp. 20-23
Author(s):  
Patrik Šarga ◽  
František Menda ◽  
František Trebuňa ◽  
Ladislav Kováč
Keyword(s):  
Differential Method ◽  
Hole Drilling ◽  
Full Potential ◽  
Easy Method ◽  
Stress Evaluation ◽  
Hole Drilling Method ◽  
Core Method ◽  
Drilling Method ◽  
Recent Developments ◽  
Ring Core

Despite the significant advantages of the Ring-Core method over the hole-drilling method, the Ring-Core method is still less common. Recent developments at our department showed the full potential of the method when using the adequate calibration coefficients. In this paper the differential method, a quick and easy method for uniform residual stress evaluation is described and the influence of its relaxation coefficients on the specimen’s dimensions is obtained.

Macro-Residual Stress Field Retrieval for Predicting the Machining Deformation of Non-Prestretched Plate

2011 ◽  
Vol 317-319 ◽  
pp. 386-392
Author(s):  
Yin Fei Yang ◽  
Ning He ◽  
Liang Li
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Large Scale ◽  
Hole Drilling ◽  
Residual Stress Field ◽  
Hole Drilling Method ◽  
Machining Deformation ◽  
Stress Changes ◽  
Drilling Method ◽  
And Control

The unknown and uneven macro-residual stresses in blanks will cause deformation on large-scale component, especially in non-prestretched plates. Based on the retrieval of stress field by measuring stress changes due to the rebalance of stresses after machining, a new idea is proposed in this paper to predict and control the machining deformation of large-scale components. It consists of analysis of the machining deformation, retrieval of macro-residual stress field, and finally optimization of following cutting process. In the retrieval process, the stresses are measured with an improved hole-drilling method and the measured data are then interpolated to 3D stress field.

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.

The Influence of Chemical Composition on Residual Stresses in NiCoMo Alloy Deposits on 12 Ni Maraging Steel

2013 ◽  
Vol 768-769 ◽  
pp. 449-455 ◽  
Author(s):  
Zoran Bergant ◽  
Janez Grum
Keyword(s):  
Residual Stress ◽  
Chemical Composition ◽  
Residual Stresses ◽  
Base Material ◽  
Stress Generation ◽  
Hole Drilling ◽  
Residual Stress Field ◽  
Hole Drilling Method ◽  
Similar Chemical ◽  
Drilling Method

The in-plane residual stresses in laser cladded specimens, made of 12-nickel precipitation hardening maraging hot-working tool steel 1.2799 (SIST EN 10027-2) are analyzed using the hole drilling method. The CO2 laser was used to deposit the alloy NiCoMo-1 with significantly higher content of nickel and cobalt with austenitic microstructure at room temperature. The Nd:YAG laser was used to deposit the maraging alloy designated NiCoMo-2, with similar chemical composition as the base material. The comparison of residual stress field showed the sign and the magnitude of residual stresses depends on the chemical composition of the clad being deposited. The high tensile residual stresses were found in NiCoMo-1 layers and favorable compressive residual stresses were found in NiCoMo-2 layers. The metallurgical aspects of residual stress generation are discussed.

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.

scholarly journals Determination of the Possible Causes of Cracks in Pins of Quick Operating Valves in Hydroelectric Power Plant

2014 ◽  
Vol 996 ◽  
pp. 827-832 ◽  
Author(s):  
Patrik Šarga ◽  
František Trebuňa ◽  
František Šimčák ◽  
Jozef Bocko
Keyword(s):  
Power Plant ◽  
Complex Analysis ◽  
Hydroelectric Power Plant ◽  
Influential Factors ◽  
Francis Turbine ◽  
Hole Drilling ◽  
Hydroelectric Power ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
The Individual

During the revision of the individual parts of a hydroelectric power plant the cracks in the pins of quick operating and revision flap valves of Francis turbine were found. Our department has been approached with a request to investigate the causes of these cracks. This paper deals with the complex analysis of influential factors, especially the measurements of residual stresses by hole-drilling method, in order to reveal the factors causing the cracks in the pins.

On the error analysis of residual stress measurements by the hole-drilling method

1993 ◽  
Vol 28 (4) ◽  
pp. 273-276 ◽  
Author(s):  
H Zhou ◽  
M D Rao
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Error Analysis ◽  
Measurement Accuracy ◽  
Strain Gauges ◽  
Hole Drilling ◽  
Residual Stress Field ◽  
Hole Drilling Method ◽  
Drilling Method ◽  
Drilling Technique

In this paper, an error analysis is carried out to discuss two important parameters that influence the accuracy in the measurement of residual stress by the hole-drilling technique. The first is the error associated with zero strain phenomenon that occurs for certain orientations of the strain gauges. A rigorous condition for zero strain point is given and measurement accuracy is discussed when the zero strain point phenomenon occurs. Secondly, the calculated residual stress field is affected by the methods chosen for the estimation and calibration of the relieved strain coefficients. The errors associated with the estimation of the relieved strain coefficients are also discussed along with their useful range for the calculation of the residual stress field.

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