Automatic Determination and Evaluation of Residual Stress Calibration Coefficients for Hole-Drilling Strain Gauge Integral Method

Strain ◽  
2009 ◽  
Vol 47 ◽  
pp. e525-e534 ◽  
Author(s):  
B. Xiao ◽  
K. Li ◽  
Y. Rong
Keyword(s):  
Residual Stress ◽  
Strain Gauge ◽  
Integral Method ◽  
Hole Drilling ◽  
Automatic Determination ◽  
Calibration Coefficients

Analysis of the Residual Stress in Multi-Layer Materials

2012 ◽  
Vol 160 ◽  
pp. 377-380
Author(s):  
Kun Shi ◽  
Yuan Yuan ◽  
Feng Tao Wei
Keyword(s):  
Residual Stress ◽  
Strain Gauge ◽  
Residual Strain ◽  
Surface Strain ◽  
Hole Drilling ◽  
Thermal Barrier ◽  
The Finite Element Method ◽  
Incremental Hole Drilling ◽  
Metallic Bond ◽  
Calibration Coefficients

The residual stresses due to the mismatch between metallic bond coat and ceramic top coat lead to a collapse of all thermal barrier system. For measuring residual strain in elastic multilayer materials, the incremental hole-drilling strain-gauge method was studied. The main stresses, which is interrelated with the residual strain, is resolved on planes that are normal to a deep hole. In order to link the surface strain to the residual stress, calibration coefficients were obtained by the finite element method. The result shows that the coefficients depend on the substrate and the type of coating, the strain gauge used and the size of the step drilled.

Simulation of Strain Gauge Thermal Effects During Residual Stress Hole Drilling Measurements

2005 ◽  
Vol 40 (7) ◽  
pp. 611-619 ◽  
Author(s):  
P Litoš ◽  
M Švantner ◽  
M Honner
Keyword(s):  
Residual Stress ◽  
Heat Flux ◽  
Strain Gauge ◽  
Computer Modelling ◽  
Thermal Strain ◽  
Sample Surface ◽  
Hole Drilling ◽  
Drilling Process ◽  
Drilling Tool ◽  
Thermomechanical Process

The hole drilling residual stress measuring method is based on drilling a small hole in a material sample and measuring the strain relieved in the hole vicinity by a special strain gauge rosette. The temperature and thermal strain induced by the drilling process can cause significant errors in the relieved strain measurement. The paper deals with computer simulation of the thermomechanical process in the sample during drilling. The first part is devoted to the evaluation of heat flux from the drilling tool to the drilled material using the sample surface temperature measured by thermography. The second part deals with determination of real strain and strain gauge thermal output (apparent strain) at the strain gauge location during and after drilling. The paper describes the computer modelling technique for solving an indirect thermal problem of drilling heat flux determination and a direct thermomechanical problem for a set of the process alternatives. Comparisons of simulated and experimentally determined temperatures and strains are presented.

scholarly journals The Application of Digital Image Correlation for Measuring Residual Stress by Incremental Hole Drilling

2008 ◽  
Vol 13-14 ◽  
pp. 65-73 ◽  
Author(s):  
Jerry D. Lord ◽  
David Penn ◽  
P. Whitehead
Keyword(s):  
Residual Stress ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Strain Gauge ◽  
Biaxial Stress ◽  
Image Correlation ◽  
Hole Drilling ◽  
Validation Data ◽  
Strain Fields ◽  
Incremental Hole Drilling

The measurement of residual stress using the incremental hole drilling is well established, but the main limitations with the conventional strain gauge approach are the requirements for surface preparation, the need for accurate alignment and drilling, the restricted range of hole geometries commensurate with the specific gauge designs, and the limited range of strain data averaged over the footprint of the strain gauge grid. Recent attempts to extend the method have seen the application of full field optical techniques such as electronic speckle pattern interferometry and holographic interferometry for measuring the strain fields around the hole, but these methods are sensitive to vibration and this limits their practical use to controlled laboratory environments. There are significant potential benefits therefore of using a more robust technique based on Digital Image Correlation (DIC), and work is presented in this study on the development of the method for measuring surface displacements and strain fields generated during incremental hole drilling. Some of the practical issues associated with the technique development, including the optimization of applied patterns, the development of the optical system and integration with current hole drilling equipment are discussed, and although measurements are only presented for a single load case - the equi-biaxial stress state introduced during shot peening - the novel aspect of this work is the integration of DIC measurements with incremental drilling and an application of the Integral Method analysis to measure the variation of residual stress with depth. Validation data comparing results from conventional strain gauge data and FE models is also presented.

An Advanced Residual Stress Determination for 3D Cylinder Structure

2005 ◽  
Vol 490-491 ◽  
pp. 62-66 ◽  
Author(s):  
Jian Luo ◽  
Guillaume Montay ◽  
Jian Lu
Keyword(s):  
Finite Element Method ◽  
Residual Stress ◽  
Finite Element ◽  
Hole Drilling ◽  
Stress Determination ◽  
Residual Stress Determination ◽  
Incremental Hole Drilling ◽  
Drilling Technique ◽  
The Relationship ◽  
Calibration Coefficients

For measuring in-depth residual stress in 3D cylinder structure easily in this paper, the semi-destructive incremental hole drilling technique combined with finite element method is used, the calibration coefficients of 3D cylinder components are calculated, and the relationship between strain and stress is determined, the changes of calibration coefficients are analysed, the residual stress of one steering joint of automobile is measured, and the errors of residual stress are discussed.

A Study of Process-Induced Residual Stress in PBGA Packages

1999 ◽  
Vol 122 (3) ◽  
pp. 262-266 ◽  
Author(s):  
Zhu Wu ◽  
Jian Lu ◽  
Yifan Guo
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Electronic Packaging ◽  
Accurate Determination ◽  
Hole Drilling ◽  
3D Fem ◽  
Molding Compound ◽  
Plastic Ball ◽  
Calibration Coefficients

Process-induced residual stresses can play a significant role in the reliability of electronic components and packages. In this paper, a practical method is developed to determine residual stresses for electronic packaging. In this method, blind holes are drilled into the specimens and relationships are established, between the released surface displacements and the corresponding residual stress, by introducing a set of calibration coefficients. A multilayer 3D-FEM model is established to determine the relevant calibration coefficients. This methodology, which combines moire´ interferometry and the incremental hole drilling method, can provide an accurate determination of residual stresses in materials and structures by precisely controlled incremental blind-hole drilling and an accurate determination of the surface in-plane displacement fields in the hole drilling region. The methodology is implemented by investigating the residual stress in the Plastic Ball Grid Array (PBGA) packages. The tensile residual stresses are determined in both the plastic molding compound and the glass/epoxy laminate chip carrier. The method is accurate, simple, convenient, and practical. More applications, in residual stress determinations and in process evaluations in electronic packaging, are anticipated. [S1043-7398(00)00103-1]

Measurement of Non-Uniform Residual Stresses Using the Hole-Drilling Method. Part II—Practical Application of the Integral Method

1988 ◽  
Vol 110 (4) ◽  
pp. 344-349 ◽  
Author(s):  
G. S. Schajer
Keyword(s):  
Integral Method ◽  
Strain Relaxation ◽  
Hole Drilling ◽  
Calibration Data ◽  
Depth Limit ◽  
Practical Applications ◽  
Hole Drilling Method ◽  
Incremental Hole Drilling ◽  
Drilling Method ◽  
Calibration Coefficients

The Integral Method for calculating non-uniform residual stress fields using strain relaxation data from the incremental hole-drilling method is examined in detail. Finite element calculations are described which evaluate the calibration coefficients required for practical applications of the method. These calibration data are tabulated for a range of hole sizes and depths. It is found that the hole drilling method is not well adapted to measuring stresses remote from the surface, and a theoretical depth limit for stress measurements of 0.5 of the mean radius of the strain gauge rosette, rm, is identified. A practical depth limit is in the range 0.3–0.4 rm.

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