Nondestructive Measurement of In-Plane Residual Stress in Silicon Strips

1999 ◽  
Vol 591 ◽  
Author(s):  
Tieyu Zheng ◽  
Steven Danyluk
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Large Deflection ◽  
Thin Plates ◽  
Nondestructive Measurement ◽  
Three Point Bending ◽  
Phase Stepping ◽  
Bending Load ◽  
Bending Loads ◽  
Processing Techniques

ABSTRACTThis paper reports the development of a shadow moiré technique to measure the in-plane residual stresses of thin, flat strips. This is an extension of prior work on the measurement of in-plane residual stresses in silicon plates and wafers. Phase stepping shadow moir6 and digital image processing techniques are employed to measure the deflections of the silicon plate specimens subjected to three-point-bending at several different loads. The measured deflections over the area of the silicon plates are fitted with an equation represented by a 2-D polynomial. With the theory of thin plates with large deflection, the fitting coefficients are used to extract the in-plane stresses at the different bending load. The residual stress is resolved by linear regression of the in-plane stresses versus bending loads.

Control of Surface Finishing Residual Stresses in Magnetic Recording Head Materials

1988 ◽  
Vol 110 (1) ◽  
pp. 87-92 ◽  
Author(s):  
S. Chandrasekar ◽  
B. Bhushan
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Magnetic Recording ◽  
Surface Finishing ◽  
Recording Head ◽  
Surface Residual Stresses ◽  
Mechanical And Physical Properties ◽  
Magnetic Recording Head ◽  
Processing Techniques

Surface finishing of magnetic recording head materials, such as ferrites, by diamond grinding and lapping results in a residual compressive stress on the surface. Residual stresses alter the magnetic properties of the ferrite causing the recording head performance to deteriorate. Hence, they need to be minimized. This paper considers the role of two processing techniques—annealing and chemical lapping—in controlling residual stress in ferrites. The effect of these processing techniques on various mechanical and physical properties of finished ferrites and the mechanism of residual stress control are discussed.

Numerical Modelling of Residual Stress and Distortion in Welded Thin Steel Plates

2008 ◽  
Author(s):  
M. Tsunori ◽  
C. M. Davies ◽  
D. Dye ◽  
K. M. Nikbin
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Welding Process ◽  
Steel Plates ◽  
Thin Plates ◽  
Welding Distortion ◽  
Butt Welding ◽  
Thin Steel ◽  
Out Of Plane ◽  
Plate Size

Current trends in ship design are to reduce panel thickness in order to minimise the vessels weight and hence maximise speed. These panels are manufactured through butt welding thin steel plates with the addition of fillet welded stiffeners. Excessive distortions are exhibited in these thin plates due to the welding process, resulting in major rectification or re-manufacturing costs. The aim of this study is to develop a tool to predict welding residual stresses and distortions in order to understand their governing factors, and thus enabling the optimum fabrication processes to be realized to minimise welding distortion. Finite element simulations are performed of the butt and fillet welding process in 4 mm thick plates of ferritic DH-36 steel and the residual stresses and distortions are predicted. Thermal and residual stress profiles are verified against experimental measurements. The effects of plate and stiffener dimensions are examined numerically. In addition, a sensitivity analysis has been carried out to quantify the effects of restraint on a small butt welded plate. It is concluded that final distortion may be severely reduced, in the plate size considered, if only an out-of-plane constraint is imposed on the plate’s surfaces. Further welding experiments are required to validate these findings.

On the Use of the Hole-Drilling Technique for Residual Stress Measurements in Thin Plates

1992 ◽  
Vol 114 (3) ◽  
pp. 292-299 ◽  
Author(s):  
R. W. Hampton ◽  
D. V. Nelson
Keyword(s):  
Experimental Data ◽  
Residual Stress ◽  
Residual Stresses ◽  
Strain Gage ◽  
Surface Preparation ◽  
Thin Plates ◽  
Hole Drilling ◽  
Thick Plates ◽  
Analysis Methodology ◽  
Drilling Technique

The strain gage blind hole-drilling technique may be used to determine residual stresses at and below the surface of components. In this paper, the hole-drilling analysis methodology for thick plates is reviewed, and experimental data are used to evaluate the methodology and to assess its applicability to thin plates. Data on the effects of gage pattern, surface preparation, hole spacing, hole eccentricity, and stress level are also presented.

Nondestructive Measurement of Welding Residual Stresses by Acousto-Elastic Technique and Prediction of Fatigue Crack Growth

1992 ◽  
Vol 114 (4) ◽  
pp. 417-421 ◽  
Author(s):  
H. Kobayashi ◽  
Y. Arai ◽  
Y. Ohsawa ◽  
H. Nakamura ◽  
A. Todoroki
Keyword(s):  
Residual Stress ◽  
Fatigue Crack ◽  
Carbon Steel ◽  
Fatigue Crack Growth ◽  
Residual Stresses ◽  
Crack Growth ◽  
Material Anisotropy ◽  
Nondestructive Measurement ◽  
Superposition Technique ◽  
Nondestructive Measurements

Nondestructive measurements of residual stresses were successfully attempted by the acoustoelastic technique on butt-welded joints of a carbon steel for nuclear piping. Usefulness of the technique considering the effect of the material anisotropy is emphasized. Based on the measured residual stresses, predictions of the fatigue crack growth were done using the superposition technique. It is shown that predictions agree well with experiments. The effect of the accuracy in residual stress measurements on the predictions is also included.

3D truss structures with coreless 3D filament winding technology

2018 ◽  
Vol 53 (15) ◽  
pp. 2077-2089 ◽  
Author(s):  
Niklas Minsch ◽  
Matthias Müller ◽  
Thomas Gereke ◽  
Andreas Nocke ◽  
Chokri Cherif
Keyword(s):  
Manufacturing Process ◽  
Composite Beam ◽  
Strength Properties ◽  
Filament Winding ◽  
Truss Structures ◽  
Three Point Bending ◽  
Rigid Frame ◽  
Bending Load ◽  
Bending Loads ◽  
Gripper Systems

A coreless manufacturing process for generic 3D rigid frame topologies will be introduced in this paper. The aim is to extend the field of filament winding from mainly 2D-shells and some exceptional cases of 3D rigid frames. This manufacturing process employs a coreless translation cross-winding method in order to continuously deposit a roving around deflection points in space. On this basis, a design methodology is being created and deductively verified by designing a beam for a three-point bending load case. The composite beam is designed on a macro level simulation approach to match the stiffness of a reference aluminum profile, which is commonly employed as structural component for robotic gripper systems in automotive assemblies. The performance of the beams is subsequently compared by three-point bending experiments. This demonstrates that the composite beam offers equivalent stiffness and strength properties with a weight-reduction potential of nearly 50% for bending loads.

Reduction of Residual Stress of Welded Joint Using Random Vibration

2004 ◽  
Author(s):  
Shigeru Aoki ◽  
Tadashi Nishimura ◽  
Tetsumaro Hiroi
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
Random Vibration ◽  
Welded Joint ◽  
Simulation Method ◽  
Thin Plates ◽  
Vibrational Load ◽  
Reduction Methods

Welding is widely used for construction of many structures. It is well known that residual stress is generated near the bead because of locally given heat. Tensile residual stress on the surface degrades fatigue strength. Some reduction methods such as heat treatment and shot peening are practically used. Authors have proposed a new method for reduction of residual stress using vibrational load during welding. In this paper, random vibration is used as vaibrational load considering noise added to input signal. White noise is used as random vibration. Two thin plates are butt welded and residual stresses near the bead are measured. It is found that tensile residual stresses near the bead are reduced when random vibration is used as vibrational load during welding. The proposed method is examined by simulation method using analytical model of the specimen. From the simulation method, it is demonstrated that tensile residual stresses near the bead are reduced when random vibration is used as vibrational load.

The Research of Processing Technique for Die-Pressing Based on FEA

2009 ◽  
Vol 419-420 ◽  
pp. 845-848
Author(s):  
Sheng Wu Wang ◽  
Ai Ling Wen ◽  
Huai Rui Zhao ◽  
Xue Song Jin ◽  
Xue Shan Zhang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Residual Stresses ◽  
Compressive Residual Stress ◽  
Cold Working ◽  
Low Carbon ◽  
Slow Increase ◽  
Fastener Hole ◽  
Bending Load ◽  
Die Pressing

The 3D finite element simulations are conducted for the cold working of a fastener hole in a low carbon steel plate. The simulation models the actual cold working process where the hole edge is chamfered with die-press. The agreement of finite element method and experimental results is good enough. The residual stresses are analyzed under the different die-press parameters and contact conditions i.e. die-pressing depth, friction factor, the die taper. The main results in this work are as follows: With increasing in chamfer depth the maximum compressive residual stress shows an increasing within the chamfer range of C1.5; the compressive residual stress is decrease with increasing friction; with increase in die taper the maximum compressive residual stress shows the slow increase. The efficiency for enhancing the load-carrying capacity of structural components with cylindrical holes subjected to bending load has been proved by means of FE simulation. The study shows that the simulations of cold working are necessary for if predicted residual stresses are to be used to assess fatigue life and for design die-pressing tool, improvement of parameters of the process of DP working.

Numerical Investigation on the Effect of Thermo-mechanical Tensioning on the Residual Stresses in Thin Stiffened Panels

2017 ◽  
Vol 33 (01) ◽  
pp. 1-11
Author(s):  
Debabrata Podder ◽  
Amith Gadagi ◽  
Nisith Ranjan Mandal ◽  
Sharat Kumar ◽  
Lavepreet Singh ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Numerical Investigation ◽  
Compressive Residual Stress ◽  
Weld Zone ◽  
Thin Plates ◽  
Far Field ◽  
Shipbuilding Industry ◽  
Stiffened Panels ◽  
Finite Element Software

In shipbuilding industry, thin plates are widely used to maintain the minimum hull weight and to increase the fuel efficiency. These thin plates, when welded, are more prone to buckling distortions. So, it is very much important to predict these buckling distortions beforehand and try to mitigate them in the fabrication stage rather than doing it later. By doing this, the competitiveness in cost and time can be increased. In this study, a numerical investigation on the reduction of buckling distortions in the fabrication of orthogonal stiffened panels as used in shipbuilding was conducted. A method of in-process distortion mitigation technique, named as thermo-mechanical tensioning (TMT) was introduced to reduce the compressive residual stress in the far-field zone. The detail stress development mechanism in TMT process is discussed here. Commercially available finite element software ANSYS® 15 was used for calculations. The simulations revealed that the peak tensile stresses in the weld zone and the corresponding far-field compressive residual stresses get significantly reduced by the implementation of TMT. Thus, with reduction of compressive residual stress, buckling of such stiffened panels is effectively mitigated.

Evaluation of the residual stress in stainless steel 304L hydraulically expanded joints

2020 ◽  
pp. 095440892096401
Author(s):  
Ying Hong ◽  
Xuesheng Wang ◽  
Yan Wang ◽  
Zhao Zhang ◽  
Yong Han
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Yield Strength ◽  
Residual Stresses ◽  
Heat Exchangers ◽  
Nuclear Power ◽  
The Finite Element Method ◽  
Power Stations ◽  
Stainless Steel 304 ◽  
Initial Clearance

Stainless steel 304 L tubes are commonly used in the fabrication of heat exchangers for nuclear power stations. The stress corrosion cracking (SCC) of 304 L tubes in hydraulically expanded tube-to-tubesheet joints is the main reason for the failure of heat exchangers. In this study, 304 L hydraulically expanded joint specimens were prepared and the residual stresses of a tube were evaluated with both an experimental method and the finite element method (FEM). The residual stresses in the outer and inner surfaces of the tube were measured by strain gauges. The expanding and unloading processes of the tube-to-tubesheet joints were simulated by the FEM. Furthermore, an SCC test was carried out to verify the results of the experimental measurement and the FEM. There was good agreement between the FEM and the experimental results. The distribution of the residual stress of the tube in the expanded joint was revealed by the FEM. The effects of the expansion pressure, initial tube-to-hole clearance, and yield strength of the tube on the residual stress in the transition zone that lay between the expanded and unexpanded region of the tube were investigated. The results showed that the residual stress of the expanded joint reached the maximum value when the initial clearance was eliminated. The residual stress level decreased with the decrease of the initial tube-to-hole clearance and yield strength. Finally, an effective method that would reduce the residual stress without losing tightness was proposed.

scholarly journals Effects of Roughness on Stresses in an Oxide Scale Formed on a Superalloy Substrate

Coatings ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 479
Author(s):  
Yang Zhao ◽  
Fan Sun ◽  
Peng Jiang ◽  
Yongle Sun
Keyword(s):  
Residual Stress ◽  
Surface Roughness ◽  
Residual Stresses ◽  
Oxide Scale ◽  
Rough Surface ◽  
Alumina Scale ◽  
Growth Stress ◽  
Oxide Growth ◽  
Substrate Thickness ◽  
Roughness Effect

The effects of surface roughness on the stresses in an alumina scale formed on a Fecralloy substrate are investigated. Spherical indenters were used to create indents with different radii and depths to represent surface roughness and then the roughness effect was studied comprehensively. It was found that the residual stresses in the alumina scale formed around the rough surface are almost constant and they are dominated by the curvature rather than the depth of the roughness. Oxidation changes the surface roughness. The edge of the indent was sharpened after oxidation and the residual stress there was released presumably due to cracking. The residual stresses in the alumina scale decrease with increase in oxidation time, while the substrate thickness has little effect, given that the substrate is thicker than the alumina scale. Furthermore, the effect of roughness on the oxide growth stress is analysed. This work indicates that the surface roughness should be considered for evaluation of stresses in coatings.

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