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.

Dependence Between Aging Treatments and Residual Stresses on Composite Laminate

2006 ◽  
Vol 524-525 ◽  
pp. 813-817 ◽  
Author(s):  
Olivier Sicot ◽  
X.L. Gong ◽  
Xiao Jing Gong ◽  
Abel Cherouat ◽  
Jian Lu
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Composite Structures ◽  
Hole Drilling ◽  
The Finite Element Method ◽  
Hole Drilling Method ◽  
Incremental Hole Drilling ◽  
Drilling Method ◽  
Initial Cycle ◽  
Calibration Coefficients

The objective of this paper is to study the influence of residual stresses due to fabrication conditions on the thermomechanical behavior of carbon/epoxy laminate structures (cross ply). These studied laminates have undergone various cycles of thermal aging. The addition of a post-cure cycle after the end of the initial cycle makes it possible to reduce the residual stresses level. The incremental hole-drilling method is used to measure the residual strain in the laminates. These measured strains and the numerical calibration coefficients obtained by the finite element method allow to calculating the residual stress distribution in composite depth. The obtained results show that heat treatments of composite structures do not lead to an important reduction the initial residual stress due the fabrication conditions.

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.

Use of Full Field of Strains Found By Grating Shearography to Determine Residual Stress

2005 ◽  
Vol 40 (7) ◽  
pp. 621-630 ◽  
Author(s):  
G Montay ◽  
J Bulhak ◽  
Y Surrel ◽  
A Vautrin ◽  
J Lu
Keyword(s):  
Residual Stress ◽  
Strain Field ◽  
Hole Drilling ◽  
The Finite Element Method ◽  
Full Field ◽  
Hole Drilling Method ◽  
Incremental Hole Drilling ◽  
Drilling Method ◽  
Very High Spatial Resolution ◽  
High Level

A new method combining grating shearography and the incremental hole drilling method has been developed to determine the residual stress distribution in depth. Grating shearography is a technique designed to determine directly the strain field with a high level of sensitivity and a very high spatial resolution. The hole drilling method is one of the most popular methods used in mechanical engineering to determine the residual stress locked into a structure. This new optical method enables the strain to be measured while taking into account the entire strain field around the hole. The finite element method is used to calibrate the method. The method was tested on an ultrasonic shot-peened aluminium specimen.

Evaluation of Welding Residual Stresses Using the Incremental Hole-Drilling Technique

2006 ◽  
Vol 514-516 ◽  
pp. 768-773
Author(s):  
Joao P. Nobre ◽  
Altino Loureiro ◽  
António Castanhola Batista ◽  
A. Morão Dias
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Numerical Study ◽  
Hole Drilling ◽  
The Finite Element Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Plasticity Effect ◽  
Incremental Hole Drilling ◽  
Drilling Technique

In this work the reliability of the hole-drilling technique (HDT) for measuring welding residual stresses was analysed. HDT residual stress results were systematically compared with those determined by X-ray diffraction. A systematic overestimation of the residual stresses determined by HDT was observed, which was mainly attributed to the possibility of the so-called plasticity effect occurring. Experimental results were discussed taking the measurement principles of both techniques into consideration. In addition, preliminary results of a numerical study, using the finite element method, will be presented for a better understanding of the plasticity effect on HDT residual stress results.

scholarly journals Residual Stresses from Incremental Hole Drilling Using Directly Deposited Thin Film Strain Gauges

2022 ◽  
Author(s):  
S. Heikebrügge ◽  
R. Ottermann ◽  
B. Breidenstein ◽  
M.C. Wurz ◽  
F. Dencker
Keyword(s):  
Thin Film ◽  
Residual Stress ◽  
Strain Gauges ◽  
Hole Drilling ◽  
Depth Profiles ◽  
Hole Drilling Method ◽  
Polymer Foil ◽  
Incremental Hole Drilling ◽  
Drilling Method ◽  
Calibration Coefficients

Abstract Background Commonly, polymer foil-based strain gauges are used for the incremental hole drilling method to obtain residual stress depth profiles. These polymer foil-based strain gauges are prone to errors due to application by glue. For example zero depth setting is thus often erroneous due to necessary removal of polymer foil and glue. This is resulting in wrong use of the calibration coefficients and depth resolution and thus leading to wrong calculations of the obtained residual stress depth profiles. Additionally common polymer foil-based sensors are limited in their application regarding e.g. exposure to high temperatures. Objective This paper aims at a first step into the qualification of directly deposited thin film strain gauges for use with the incremental hole drilling method. With the directly deposited sensors, uncertainties regarding the determination of calibration coefficients and zero depth setting due to the absence of glue can be reduced to a minimum. Additionally, new areas of interest such as the investigation of thermally sprayed metallic layers can be addressed by the sensors due to their higher temperature resilience and their component inherent minimal thickness. Methods For the first time, different layouts of directly deposited thin film strain gauges for residual stress measurements were manufactured on a stainless steel specimen. Strain measurements during incremental hole drilling using a bespoke hole drilling device were conducted. Residual stress depth profiles were calculated using the Integral method of the ASTM E837 standard. Afterwards, strain measurements with conventional polymer foil-based strain gauges during incremental hole drilling were conducted and residual stress depth profiles were calculated accordingly. Finally the obtained profiles were compared regarding characteristic values. Results The residual stress depth profiles obtained from directly deposited strain gauges generally match the ones obtained from conventional polymer foil based strain gauges. With the novel strain gauges, zero depth setting is simplified due to the absence of glue and polymer foil. With the direct deposition, a wide variety of rosette designs is possible, enabling a more detailed evaluation of the strain field around the drilled hole. Conclusions The comparative analysis of the obtained residual stress depth profiles shows the general feasibility of directly deposited strain gauges for residual stress measurements. Detailed investigations on uncertainty sources are still necessary.

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