The Effect of Quench-Induced Residual Stresses on the Distortion of Machined Thin-Walled Parts

2015 ◽  
Vol 24 (10) ◽  
pp. 3933-3941 ◽  
Author(s):  
Soroush Masoudi ◽  
Ghasem Amirian ◽  
Ehsan Saeedi ◽  
Mohammad Ahmadi
Keyword(s):  
Residual Stresses ◽  
Thin Walled

Analysis of circumferentially welded thin-walled cylinders to study the effects of tack weld orientations and joint root opening on residual stress fields

2009 ◽  
Vol 223 (5) ◽  
pp. 1037-1049 ◽  
Author(s):  
N U Dar ◽  
E M Qureshi ◽  
A M Malik ◽  
M M I Hammouda ◽  
R A Azeem
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Arc Welding ◽  
Operating Conditions ◽  
Stress Fields ◽  
Welded Structures ◽  
Prime Concern ◽  
Thin Walled ◽  
Tack Weld ◽  
Welding Processes

In recent years, the demand for resilient welded structures with excellent in-service load-bearing capacity has been growing rapidly. The operating conditions (thermal and/or structural loads) are becoming more stringent, putting immense pressure on welding engineers to secure excellent quality welded structures. The local, non-uniform heating and subsequent cooling during the welding processes cause complex thermal stress—strain fields to develop, which finally leads to residual stresses, distortions, and their adverse consequences. Residual stresses are of prime concern to industries producing weld-integrated structures around the globe because of their obvious potential to cause dimensional instability in welded structures, and contribute to premature fracture/failure along with significant reduction in fatigue strength and in-service performance of welded structures. Arc welding with single or multiple weld runs is an appropriate and cost-effective joining method to produce high-strength structures in these industries. Multi-field interaction in arc welding makes it a complex manufacturing process. A number of geometric and process parameters contribute significant stress levels in arc-welded structures. In the present analysis, parametric studies have been conducted for the effects of a critical geometric parameter (i.e. tack weld) on the corresponding residual stress fields in circumferentially welded thin-walled cylinders. Tack weld offers considerable resistance to the shrinkage, and the orientation and size of tacks can altogether alter stress patterns within the weldments. Hence, a critical analysis for the effects of tack weld orientation is desirable.

Average Residual Stresses in Hard Physical Vapor Deposited (PVD) Coatings

2019 ◽  
Vol 799 ◽  
pp. 20-25
Author(s):  
Harri Lille ◽  
Alexander Ryabchikov ◽  
Jakub Kõo ◽  
Valdek Mikli ◽  
Eron Adoberg ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Front Surface ◽  
Back Surface ◽  
Length Variation ◽  
Pvd Coatings ◽  
Cross Sectional ◽  
Average Residual ◽  
Thin Walled ◽  
Compressive Residual Stresses ◽  
Very High

In this study we determined average residual stresses in hard nitride PVD AlCrN, TiAlN and TiCN coatings through simultaneous measurement of length variation in thin-walled tubular substrates and of the curvature of plate substrates. A device for measurement of the length of the tube was developed. Inside the depositing chamber the tube and the plate were fixed parallel in the relation to the axis of the rotating cathode. One batch of plate samples was produced by deposition on front surface (facing the cathode) and the other batch, by deposition on back surface (with back to the cathode). The cross-sectional microstructure and thickness of the coatings were investigated by means of scanning electron microscopy (SEM). The thicknesses of the coatings deposited on front and back surfaces of the plates and on the tube were significantly different. The values of average compressive residual stresses, determined by both methods, were very high irrespective of coating thickness. It was found that the values of compressive residual stresses in the coating were dependent on the shape of the substrate and on its position in the relation to the axis of the rotating cathode.

scholarly journals Numerical Simulation on Moulded Thin-Walled Parts via Injection Moulding Process

2014 ◽  
Vol 575 ◽  
pp. 73-77
Author(s):  
M.D. Azaman ◽  
S.M. Sapuan ◽  
Shamsuddin Sulaiman ◽  
E.S. Zainudin ◽  
Abdan Khalina
Keyword(s):  
Numerical Simulation ◽  
Shear Stress ◽  
Residual Stresses ◽  
Current Trend ◽  
Light Weight ◽  
Moulding Process ◽  
Injection Moulding Process ◽  
Low Shear Stress ◽  
Thin Walled ◽  
Low Shear

The current trend in the industry is to produce thin, light weight, and environmental products. In this project, flat or shallow thin-walled parts were designed and moulded lignocellulosic polymer composites (PP + 50 wt% wood) to visualize the processability via moulding simulation. This studied focused on the filling, shear stress at wall, and in-cavity residual stresses behaviors. The shallow thin-walled part is preferable in moulding PP + 50 wt% wood due to economically in processing, low shear stress distribution and low residual stresses than the flat thin-walled part.

scholarly journals Erratum to: The Effect of Quench-Induced Residual Stresses on the Distortion of Machined Thin-Walled Parts

2015 ◽  
Vol 25 (2) ◽  
pp. 718-718
Author(s):  
Soroush Masoudi ◽  
Ghasem Amirian ◽  
Ehsan Saeedi ◽  
Mohammad Ahmadi
Keyword(s):  
Residual Stresses ◽  
Thin Walled

scholarly journals The method of reconstruction of residual stresses and plastic deformations in thin-walled pipelines in the delivery state and after bilateral vibro-shock surface hardening with a shot

2020 ◽  
pp. 123-133
Author(s):  
V. P Radchenko ◽  
V. Ph Pavlov ◽  
T. I Berbasova ◽  
M. N Saushkin
Keyword(s):  
Experimental Data ◽  
Plastic Deformation ◽  
Residual Stresses ◽  
Strain Tensor ◽  
Anisotropy Parameter ◽  
Surface Plastic ◽  
Phenomenological Method ◽  
Stress Strain ◽  
Plastic Deformations ◽  
Thin Walled

We suggest the phenomenological method of reconstructing the fields of residual stresses and plastic deformations in thin-walled cylindrical tubes made of Х18N10Т steel in the delivery state and after a simultaneous bilateral surface plastic hardening by the vibration-shot blasting of the surface with beads on a special vibrating stand. A cylindrical container filled with three-millimeter beads was attached to it. The tubes were 50 % filled with one-millimeter beads, and they were placed inside the container. The axis of the tube and the container coincided. The space between the tube and the container was 80 % filled with beads. The vibrational frequency of the stand was 18.5 KHz, the hardening time was 20 minutes. The tube in the container was rotated to ensure uniform hardening. We determined the experimental values of residual stresses σθ and σ z in the surface layers using the method of rings and strips with the procedure of the layer-by-layer electrochemical picking of the hardened layers. For this purpose, the experimentally measured values of the beam-strip deflection and the angular opening of the cut ring (changing the diameter) were used. The hardening anisotropy parameter which relates the axial and circumferential components of plastic deformation was introduced into the mathematical model. In solving the stated problems the hypotheses of plastic incompressibility of the material, the absence of secondary plastic deformations of the material in the compression region of the surface layer, as well as the hypothesis of flat sections and straight radii were used. We described the method aimed at solving this type of boundary value problems of reconstructing stress-strain states, which makes it possible to determine the missing component σ r and all the components of the tensor of residual plastic deformations (off-diagonal components of the tensors of stresses and deformations were not considered). The method of reconstructing the stress-strain state is universal, because it has shown its operability both in determining the technological fields of residual stresses, as well as the irreversible strains in the samples in the delivered state after mechanical operations, and after bilateral surface plastic deformation. The adequacy of the calculated data was verified, which was obtained using the phenomenological method of reconstructing the stress and strain fields of the experimental data for the samples in the delivery state and after hardening. The correspondence of the calculated and experimental data was matched. The numerical values are given for the anisotropy parameter connecting the circumferential and axial irreversible strains, for samples, in the delivery state, its numerical value is 0.1, and, for the hardened samples, it is 4.2. This indicates a significant anisotropy of the distribution of the axial and circumferential components of the residual strain tensor. It has been established that the compressive residual stresses are observed in the delivery state in the region adjacent to the inner surface, and the tensile stresses are observed in the layer on the outer surface. Only compressive stresses are observed in both regions after hardening, which significantly exceed in module similar stresses for the samples in the delivery state. The main results are illustrated by the tabular data and the corresponding diagrams of the distribution of residual stresses along the depth of the hardened layer.

A numerical prediction of residual stress for a thin-walled part with geometrical features fabricated by GMA-based additive manufacturing

2019 ◽  
Vol 26 (2) ◽  
pp. 299-308
Author(s):  
Rong Li ◽  
Jun Xiong
Keyword(s):  
Residual Stress ◽  
Additive Manufacturing ◽  
Stress Distribution ◽  
Residual Stresses ◽  
Residual Stress Distribution ◽  
Stress Distributions ◽  
Content Type ◽  
Geometrical Features ◽  
Longitudinal Residual Stress ◽  
Thin Walled

Purpose An accurate prediction of process-induced residual stress is necessary to prevent large distortion and cracks in gas metal arc (GMA)-based additive manufactured parts, especially thin-walled parts. The purpose of this study is to present an investigation into predicting the residual stress distributions of a thin-walled component with geometrical features. Design/methodology/approach A coupled thermo-mechanical finite element model considering a general Goldak double ellipsoidal heat source is built for a thin-walled component with geometrical features. To confirm the accuracy of the model, corresponding experiments are performed using a positional deposition method in which the torch is tilted from the normal direction of the substrate. During the experiment, the thermal cycle curves of locations on the substrate are obtained by thermocouples. The residual stresses on the substrate and part are measured using X-ray diffraction. The validated model is used to investigate the thermal stress evolution and residual stress distributions of the substrate and part. Findings Decent agreements are achieved after comparing the experimental and simulated results. It is shown that the geometrical feature of the part gives rise to an asymmetrical transversal residual stress distribution on the substrate surface, while it has a minimal influence on the longitudinal residual stress distribution. The residual stress distributions of the part are spatially uneven. The longitudinal tensile residual stress is the prominent residual stress in the central area of the component. Large wall-growth tensile residual stresses, which may cause delamination, appear at both ends of the component and the substrate–component interfaces. Originality/value The predicted residual stress distributions of the thin-walled part with geometrical features are helpful to understand the influence of geometry on the thermo-mechanical behavior in GMA-based additive manufacturing.

Investigation of Residual Stresses and some Elastic Properties of Brush-Plated Gold and Silver Galvanic Coatings

2012 ◽  
Vol 527 ◽  
pp. 125-130 ◽  
Author(s):  
Harri Lille ◽  
Jakub Kõo ◽  
Alexander Ryabchikov ◽  
Renno Reitsnik ◽  
Renno Veinthal ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Residual Stresses ◽  
Experimental Parameter ◽  
Instrumented Indentation ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thin Walled ◽  
Copper Ring ◽  
Scanning Electron

Nickel-hardened gold and silver coatings were brush-plated from a commercial SIFCO Dalic Solution (Gold Hard Alloy), Code SPS 5370, and Silver Hard Heavy Build, Code SPS 3080, on unclosed thin-walled copper ring substrates. To determine residual stresses, the conventional curvature method (common among the electrodeposition methods) was applied, where the substrate was coated with certain thickness and then the slit increment (bending deflection) of the substrate was measured as an experimental parameter. Residual stresses on gold coatings were also determined by X-ray diffraction (XRD) based on the sin2 method. The values of residual stresses determined by the curvature method and by the XRD technique were comparable. Relaxation of residual stresses was observed. An equation for approximation of the change of residual stresses was applied assuming that the dependence of residual stresses on relaxation time is linear-fractional. The surface morphology and microstructure of the coatings was studied by means of scanning electron microscopy (SEM). The magnitudes of the modulus of elasticity and of the nanohardness of the coatings were obtained by instrumented indentation.

Residual Stresses Distributions within Thin-Walled Ceramic-Metal Seal

2012 ◽  
Vol 503-504 ◽  
pp. 428-431 ◽  
Author(s):  
Guo Liang Zhang ◽  
Lei Shi ◽  
Da Zhi Jin
Keyword(s):  
Thermal Expansion ◽  
Residual Stresses ◽  
Fem Simulation ◽  
Matrix Composites ◽  
Thermal Expansion Coefficients ◽  
Expansion Behavior ◽  
Metal Seal ◽  
Significant Difference ◽  
Thin Walled ◽  
Typical Configuration

Due to significant difference of thermal expansion coefficients between ceramic and metal, the residual stresses are deemed to be induced into the interior of matrix composites within the ceramic-metal seal systems. Many investigations of the residual stresses distributions on dissimilar solid materials joints so far have been carried out theoretically and experimentally, whereas ones of the residual stresses distributions within the thin-walled ceramic-metal seal systems are rarely performed. In order to obtain information for improving their seal structures in the future, the residual stresses distributions resulted from the thermal expansion behavior in the typical configuration of the thin-walled ceramic-metal seal are investigated by theoretical formulae, experimental observation and finite element method (FEM) simulation in this paper. The changing trends of the computational results of the residual stresses distributions agree with the experimental results of the measurement with X-ray diffractometer. The overall residual stresses are found to increase drastically near the welding interfaces. The highest tensile stress occurs at the outer surfaces of the ceramic near the welding interfaces.

Stability and Vibration of Imperfect Column and Slender Web

2014 ◽  
Vol 969 ◽  
pp. 328-331
Author(s):  
Ľuboš Šnirc ◽  
Jan Ravinger
Keyword(s):  
Residual Stresses ◽  
Linear Theory ◽  
Stiffness Matrix ◽  
Natural Vibration ◽  
Thin Walled Structures ◽  
Geometrical Imperfections ◽  
Thin Walled ◽  
Non Destructive ◽  
Structural Imperfections ◽  
Lagrange Description

Using the geometric non-linear theory (The Total Lagrange Description) in dynamics we can establish the problem of the natural vibration of the structure including the effects of the structural and geometrical imperfections. The incremental stiffness matrix can take into account the residual stresses (structural imperfections) and the geometrical initial displacements (geometrical imperfections) as well. The behaviour of columns, frames and thin-walled structures is sensitive to imperfections. This theory and results can be used as a base for the non-destructive method for the evaluation of the level of the load and the imperfections.

Sign in / Sign up

Export Citation Format

Share Document