scholarly journals Closed-form solutions of hole distortion for use in deep-hole drilling measurements of residual stress in orthotropic plates

2016 ◽  
Vol 52 (2) ◽  
pp. 77-82 ◽  
Author(s):  
Carlos Garza ◽  
Anton Shterenlikht ◽  
Martyn J Pavier ◽  
David J Smith
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Closed Form ◽  
Hole Drilling ◽  
Shear Stresses ◽  
Deep Hole ◽  
Element Analysis ◽  
Deep Hole Drilling ◽  
Closed Form Solutions

The measurement of residual stress using the deep-hole drilling method relies on the evaluation of the distortion of a hole in a plate under the action of far-field direct and shear stresses. While closed-form solutions exist for the isotropic materials, in previous work for orthotropic materials, finite element analysis has been used to find the distortion. In this technical note, Lekhnitskii’s analysis is used to find closed-form solutions for the distortion of a circular hole in an orthotropic plate. The results are compared with those of finite element analysis for a range of material properties with excellent agreement.

Validation of Nitinol SMA Characteristics Using Finite Element Analysis and Closed Form Solutions

2013 ◽  
Vol 856 ◽  
pp. 147-152
Author(s):  
S.H. Adarsh ◽  
U.S. Mallikarjun
Keyword(s):  
Experimental Data ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Closed Form ◽  
Closed Form Solution ◽  
Form Solution ◽  
Fe Analysis ◽  
Element Analysis ◽  
Complex Behaviour ◽  
Closed Form Solutions

Shape Memory Alloys (SMA) are promising materials for actuation in space applications, because of the relatively large deformations and forces that they offer. However, their complex behaviour and interaction of several physical domains (electrical, thermal and mechanical), the study of SMA behaviour is a challenging field. Present work aims at correlating the Finite Element (FE) analysis of SMA with closed form solutions and experimental data. Though sufficient literature is available on closed form solution of SMA, not much detail is available on the Finite element Analysis. In the present work an attempt is made for characterization of SMA through solving the governing equations by established closed form solution, and finally correlating FE results with these data. Extensive experiments were conducted on 0.3mm diameter NiTinol SMA wire at various temperatures and stress conditions and these results were compared with FE analysis conducted using MSC.Marc. A comparison of results from finite element analysis with the experimental data exhibits fairly good agreement.

Deep Hole Drill Residual Stress Measurement Technique Experimental Validation

2006 ◽  
Vol 524-525 ◽  
pp. 549-554 ◽  
Author(s):  
W.R. Mabe ◽  
W.J. Koller ◽  
A.M. Holloway ◽  
P.R. Stukenborg
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Test Specimen ◽  
Experimental Validation ◽  
Stress Measurement ◽  
Reference Solution ◽  
Deep Hole ◽  
Element Analysis ◽  
Validation Test

This paper presents the results of an experimental validation of the deep hole drill residual stress measurement method. A validation test specimen was fabricated and plastically loaded to impose a permanent residual stress field within the specimen. The validation test specimen was designed to provide a variety of stress profiles as a function of location within the specimen. A finite element analysis of the validation test specimen was performed in order to provide a reference solution for comparison to the deep hole drill experimental results. Results from experimental testing of the validation test specimen agree well with the finite element analysis reference solution, thereby providing further validation of the deep hole drill method to measure residual stresses.

Analysis and Optimization of the Deep-Hole Drilling Technique in Measuring Complex Residual Stress

2017 ◽  
Author(s):  
Gang Zheng ◽  
Sayeed Hossain ◽  
Feng Shen ◽  
Chris Truman
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Longitudinal Axis ◽  
Hole Drilling ◽  
Internal Diameter ◽  
Deep Hole ◽  
Element Analysis ◽  
Deep Hole Drilling ◽  
Drilling Technique ◽  
Technique Comparison

The aim of the present study was to utilize a complex residual stress generated within a welded circular disc to further investigate the standard deep-hole drilling (DHD) technique and the newly developed over-coring deep-hole drilling (oDHD) technique in accurately measuring residual stresses well over yield stress. Finite Element Analysis (FEA) was used to optimize and extend the deep-hole drilling technique and improve its accuracy. The standard DHD procedure involves 4 steps. (1) A reference hole is gun-drilled through the component. (2) The internal diameter of the reference hole is measured at different angular positions through the depth of the component. (3) A cylindrical section with the reference hole as its longitudinal axis is trepanned free from the component. (4) Finally, the relaxed internal diameter is re-measured at the same angular positions and the same depths. The drilling, trepanning procedures and the parameters of the deep-hole drilling technique were all studied in detail to optimize the technique. Comparison is made between the FEA predicted residual stress in the weld, the measurements and the reconstructed residual stresses of the measurements. The close correlations confirmed the suitability of new modifications made in the deep-hole drilling technique to account for plasticity when measuring near yield residual stresses present in a component.

An Algorithm for Reducing the Size of Finite Element Closed-Form Source Code Files

2009 ◽  
Author(s):  
Sara McCaslin ◽  
Kent Lawrence
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Closed Form ◽  
Source Code ◽  
Simple Algorithm ◽  
Higher Order ◽  
Error Estimator ◽  
Element Analysis ◽  
Closed Form Solutions ◽  
Large Source

Closed-form solutions, as opposed to numerically integrated solutions, can now be obtained for many problems in engineering. In the area of finite element analysis, researchers have been able to demonstrate the efficiency of closed-form solutions when compared to numerical integration for elements such as straight-sided triangular [1] and tetrahedral elements [2, 3]. With higher order elements, however, the length of the resulting expressions is excessive. When these expressions are to be implemented in finite element applications as source code files, large source code files can be generated, resulting in line length/ line continuation limit issues with the compiler. This paper discusses a simple algorithm for the reduction of large source code files in which duplicate terms are replaced through the use of an adaptive dictionary. The importance of this algorithm lies in its ability to produce manageable source code files that can be used to improve efficiency in the element generation step of higher order finite element analysis. The algorithm is applied to Fortran files developed for the implementation of closed-form element stiffness and error estimator expressions for straight-sided tetrahedral finite elements through the fourth order. Reductions in individual source code file size by as much as 83% are demonstrated.

Residual Stress Finite Element Analysis and Measurements of a Tube Penetration J-Groove Attachment Weld in a Hemispherical Head of a Large Ferritic Pressure Vessel: Part II — Outer Nozzle

2006 ◽  
Author(s):  
R. Dennis ◽  
N. Leggatt ◽  
C. T. Watson ◽  
E. Kingston ◽  
D. J. Smith
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Pressure Vessel ◽  
Element Model ◽  
Hole Drilling ◽  
Poor Correlation ◽  
Element Analysis ◽  
The Finite Element Model

A programme of work was undertaken to gain an understanding of the residual stress levels in the tube penetration J-groove welds in a hemispherical head of a large stainless steel clad ferritic pressure vessel. This second part of a two-part paper describes the finite element analysis that was carried out to model an off-centre outer tube to vessel head weld. A 3D finite element residual stress model was developed. The complex bead deposition sequence of the actual weld was simulated by a bead lumping approach using 9 passes. The results from the finite element analyses were compared with both surface and through thickness stress measurements. These measurements were taken on a mock weld that was representative of the actual component. The surface measurements were taken by using an incremental centre hole drilling technique. The through thickness values were obtained from deep hole drilling measurements at three positions around the circumference of the weld. For this off-centre penetration the cladding process was not modelled nor was clad applied to the test mock-up. The finite element results and the measured values showed similar trends in the variation of stress around the circumference of the weld. A poor correlation between measurements and analytical results was obtained at the lower hillside position. A major reason for the discrepancy is believed to be that the bead lumping approach that was used in the finite element model was not a sufficiently refined representation of the actual weld bead deposition sequence. Note however that one of the aims of this finite element analysis was to quantify the variations between the centre tube presented in the first part of this paper and the off centre tube presented here. In this regard the finite element model and measurements compared well. The finite element model was also used to carry out two sensitivity studies that investigated the effects upon residual stress of tube geometry and material properties. For the case where a nozzle tube was extended significantly below the vessel head inner surface the results showed the stresses to be significantly higher than the baseline case.

scholarly journals FINITE ELEMENT ANALYSIS OF TOOLS FOR DEEP DRILLING TECHNOLOGY

2021 ◽  
Author(s):  
Natal'ya Turkina ◽  
Aleksandr Chukarin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Software Package ◽  
Hole Drilling ◽  
Deep Hole ◽  
Ansys Software ◽  
Deep Drilling ◽  
Element Analysis ◽  
Drilling Technology ◽  
Modern Tool

Using the ANSYS software package, the issues of strength of the drill head and temperature distribution were considered, the design of a modern tool for deep hole drilling was analyzed, and modal analysis was carried out to exclude possible resonance phenomena.

Measurement of Residual Stresses in Large Industrial Components Using the Deep Hole Drilling Technique

2005 ◽  
Author(s):  
X. Ficquet ◽  
C. E. Truman ◽  
D. J. Smith ◽  
T. B. Brown ◽  
T. A. Dauda
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Excellent Agreement ◽  
Stress Component ◽  
Hole Drilling ◽  
Deep Hole ◽  
Deep Hole Drilling ◽  
Drilling Technique ◽  
Compressive Residual Stresses

“ELIXIR – Extending Plant Life Through Improved Fabrication and Advanced Repair Methodology” was a European Union FP5 sponsored project. During the duration of the Elixir project, much work was directed at providing the necessary data for the validation of numerical modelling techniques applied to residual stress generation and hydrogen diffusion arising from the welding process. The project focussed around four industrial applications, namely petrochemical, boiler, offshore and submarine. This paper presents through-thickness residual stress measurements obtained by the University of Bristol on two of the large industrial components. The results were obtained using the deep hole drilling technique and compared to Finite Element predictions provided by other partners. The components considered are a large P275 steel set-in nozzle, typical of a boiler application and a large S690 steel set-on nozzle, typical of an offshore application. The boiler application consisted of a nozzle of diameter 600mm and thickness 50mm, on a pipe of diameter 1100mm and 100mm thickness. The offshore application was a nozzle of diameter 900mm and thickness 50mm, on a pipe of diameter 1050mm and 50mm thickness. Both the longitudinal and transverse stresses measured using deep hole drilling showed excellent agreement with Finite Element predictions through the thickness of the boiler sample. On the top surface, a zone of tensile residual stresses, over a distance of approximately 40mm, was revealed, which was equilibrated by a zone of compressive residual stresses over the final 50mm of thickness. Results for the offshore application demonstrated that at the front surface, both of the stress components were essentially zero, but both the longitudinal and transverse components rose rapidly to maxima of approximately 500MPa and 220MPa, respectively. Tensile residual stresses were supported over a distance of approximately 30mm. Over the final 20mm of thickness, compressive residual stresses existed, which again fell to approximately zero on the back face. There is excellent agreement between measurements and the Finite Element predictions for the transverse stress component, but less good agreement between measurements and predictions of the longitudinal stress component.

Residual Stress Finite Element Analysis and Measurements of a Tube Penetration J-Groove Attachment Weld in a Hemispherical Head of a Large Ferritic Pressure Vessel: Part I — Centre Nozzle

2006 ◽  
Author(s):  
C. T. Watson ◽  
A. Gregg ◽  
R. Dennis ◽  
N. Leggatt ◽  
E. Kingston ◽  
...  
Keyword(s):  
Residual Stress ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Vessel ◽  
Hole Drilling ◽  
General Level ◽  
Finite Element Analyses ◽  
Element Analysis ◽  
Before And After ◽  
Surface Measurements

A programme of work was undertaken to gain an understanding of the residual stress levels in the tube penetration J-groove attachment welds in a hemispherical head of a large stainless steel clad ferritic pressure vessel. In this first part, of a two part paper, the finite element analyses that were carried out to model the centre nozzle penetration are described. Two axisymmetric residual stress finite element models were developed. One used an accurate representation of the weld bead deposition sequence and the other a bead lumping approach to model bead deposition. The results from the finite element analyses were compared with both surface and through thickness stress measurements. These measurements were taken on a mock-up weld that was representative of the actual component. The surface measurements were taken by using an incremental centre hole drilling technique (ICHD). The through thickness values were obtained from deep hole drilling (DHD) measurements. The DHD measurements were taken before and after the cladding of the mock-up. The analytical results from the two axisymmetric models showed the simpler blocked dump model approach to be reasonable in capturing the general level of stress. The finite element analysis results showed good agreement with the measurements in the radial direction, but predicted greater than the measured values in the hoop direction.

Sign in / Sign up

Export Citation Format

Share Document