Effects of Substrate Parameters on the Residual Stress and Deflection of Ti-6Al-4V Walls in Additive Manufacturing Process

2020 ◽  
Vol 976 ◽  
pp. 156-161
Author(s):  
Shu Guang Chen ◽  
Yi Du Zhang ◽  
Qiong Wu ◽  
Han Jun Gao
Keyword(s):  
Heat Transfer ◽  
Residual Stress ◽  
Additive Manufacturing ◽  
Three Dimensional ◽  
Element Model ◽  
Length Change ◽  
Deposition Process ◽  
Stress Profile ◽  
Maximum Deflection ◽  
Residual Stress Profile

Given substrate parameters affect the heat transfer during additive manufacturing (AM) deposition process, the precision and residual stress of the component will also be affected. Such effect is an important aspect that should be considered but has not been reported. Thus, this paper presents a three-dimensional thermo-mechanical finite element model to study the effects of substrate parameters on the residual stress of Ti-6Al-4V walls during the AM process. The thermal and deflection histories and residual stress profile with different substrate parameters were investigated. Results show that the influence of the substrate height on the deflection, heat transfer and residual stress is most obvious, the length change has little influence on the deflection and stress distribution. The maximum deflection difference between the heights of 2.4 and 10.4 mm is 92.12%, the maximum deflection is reduced by 39.65% with the width increased from 15.4mm to 35.4mm. And the increased height is beneficial to the uniform of Z component residual stress but decrease uniformity of Y component residual stress.

Residual Stress in Plain Carbon Steel Induced by Laser Hardening

2015 ◽  
Vol 812 ◽  
pp. 321-326 ◽  
Author(s):  
A. Filep ◽  
Márton Benke ◽  
Valéria Mertinger ◽  
Gábor Buza
Keyword(s):  
Heat Transfer ◽  
Residual Stress ◽  
Residual Stresses ◽  
Plain Carbon Steel ◽  
Laser Hardening ◽  
Manufacturing Processes ◽  
Stress Profile ◽  
Multiple Sources ◽  
Residual Stress Profile ◽  
Hardening Treatment

Technological residual stresses have great importance in the manufacturing processes and the lifetime of components. The residual stresses formed by quenching can be very diverse because of its multiple sources. Alternative quenching processes such as laser hardening have a great potential for different applications. The direction of heat transfer during laser hardening is the opposite compared to conventional quenching. This further increases the complexity of the developed stress state. The residual stress profile and the microstructure formed by laser hardening treatment are investigated in the present manuscript.

Numerical Analysis of the Effect of Machining on the Depth of Yield, Maximum Firing Pressure and Residual Stress Profile in an Autofrettaged Gun Tube

2003 ◽  
Vol 125 (3) ◽  
pp. 342-346 ◽  
Author(s):  
Amer Hameed ◽  
R. D. Brown ◽  
J. G. Hetherington
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Optimization Technique ◽  
Circumferential Stress ◽  
Element Model ◽  
Stress Profile ◽  
Residual Stress Field ◽  
Element Analysis ◽  
Residual Stress Profile ◽  
Experimental Findings

A multi-linear kinematic, two dimensional finite element model incorporating Bauschinger effect, developed using ANSYS commercial software is used to determine the effect of machining both at the bore and at the outside diameter, on the depth of yield, maximum firing pressure and final residual stress field present in an autofrettaged gun tube. The model, which is in good agreement with experimental findings, clearly shows that the reduction in maximum compressive circumferential stress is more sensitive to internal machining than to external machining; the depth of yield remains stable and there is no movement of the elastic-plastic interface, relative to its location before material removal. If the internal machining removes material in which reverse yield has occurred, the maximum firing pressure is not affected. The finite element analysis supported by experimental evidence thus leads to an optimization technique for gun tube design.

Finite Element Simulation of the Residual Stress States after Shot Peening

2006 ◽  
Vol 524-525 ◽  
pp. 349-354 ◽  
Author(s):  
Manuel Klemenz ◽  
Volker Schulze ◽  
Otmar Vöhringer ◽  
Detlef Löhe
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Finite Element Simulation ◽  
Shot Peening ◽  
Three Dimensional ◽  
Material Model ◽  
Stress Profile ◽  
Viscoplastic Material ◽  
Residual Stress Profile ◽  
Element Simulation

In a three-dimensional Finite-Element-Simulation of shot peening, a combined isotropickinematic viscoplastic material description was introduced in order to describe the cyclic softening effects during peening. After verifying the model in the simulation of push-pull tests at different strain amplitudes it could be used for the shot peening simulation. The simulated residual stress profile is compared with experimental results determined by X-ray diffraction and with simulated results of a simpler isotropic viscoplastic material model.

Statistical Analysis of Pipe Girth Weld Experimental Residual Stress Data

2009 ◽  
Author(s):  
Brahim Nadri ◽  
Mike C. Smith ◽  
Christopher E. Truman ◽  
David J. Smith ◽  
P. John Bouchard
Keyword(s):  
Residual Stress ◽  
Statistical Analysis ◽  
Residual Stresses ◽  
Structural Integrity ◽  
Measurement Techniques ◽  
Three Dimensional ◽  
Real Life ◽  
Stress Profile ◽  
Residual Stress Profile ◽  
Weld Residual Stress

Thermal and mechanical processes during welding introduce complex three-dimensional distributions of residual stress. Management of residual stresses represents a major challenge for engineers in order to achieve safe and reliable operation of existing engineering plants. Consideration of how such stresses vary through the wall within welded components is critical in structural integrity assessments. Development of more accurate and realistic weld residual stress profiles through statistical analysis of high quality measured data is highly desirable. This cannot be achieved without adequate interpretation of measured weld residual stress data through the development of an appropriate framework. At previous PVP conferences such a framework was detailed. However, the framework was used to analyse and interpret welding residual stresses measured in highly controlled test specimens of simple geometry. This paper represents the extension of the framework to interpret real plant weld residual stress data. Specifically, the results of residual stress measurements on nine pipe girth welds are analysed statistically with the objective of providing a justifiable residual stress profile. The measurement results were obtained using different measurement techniques from different laboratories. The extension to real life data, unsurprisingly, reveals some unanticipated difficulties compared to the simple test specimen previously considered.

An Analytical Method for Estimating Welding-Induced Plastic Zone Size for Residual Stress Profile Development

2015 ◽  
Author(s):  
Xianjun Pei ◽  
Shaopin Song ◽  
Pingsha Dong
Keyword(s):  
Heat Transfer ◽  
Residual Stress ◽  
Finite Element ◽  
Plastic Zone ◽  
Analytical Method ◽  
Plastic Zone Size ◽  
Stress Profile ◽  
Zone Size ◽  
Residual Stress Profile ◽  
Residual Stress Analysis

As demonstrated in a recent comprehensive study on construction of full-field residual stress profiles for fitness-for-service assessment of pressure vessel and piping components, a reasonable estimate of welding-induced plastic zone size is necessary for introducing a shell theory based solution form (Song et al, 2015 [1–2]). This paper presents an analytical method for estimating plastic zone size by first solving an equivalent one dimensional heat transfer problem in which weld zone is represented by a line segment with initial temperature at melting. Thermoplasticity conditions are then imposed by assuming elastic perfectly plastic behaviors. Finally, an analytical expression is obtained to relate plastic zone boundary to maximum temperature field distribution experienced by material points within the whole domain over the entire heating and cooling history. The solution can be further expressed by a rather simple form with the identification of a characteristic length parameter that signifies inflection point of temperature distribution. So estimated plastic zone sizes for various welded joint types have been compared with finite element residual stress analysis results in which sequentially coupled welding heat transfer and thermo-mechanical analysis procedures are used. A good agreement has been achieved for all cases analyzed. Compared with conventional finite element residual stress analysis procedures, this method offers significant simplicity and efficiency, while being reasonably accurate, particularly for applications in residual stress profile estimation and in evaluation of welding induced distortions in complex structures.

A Sensitivity Analysis of Shot Peening Parameters

2006 ◽  
Author(s):  
Abdalla Elbella ◽  
Vishal Rami ◽  
Jyothi Hogirala
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Process Parameters ◽  
Shot Peening ◽  
Target Material ◽  
Element Model ◽  
Stress Profile ◽  
Explicit Finite Element ◽  
Residual Stress Profile ◽  
Subsurface Layers

Shot peening process is largely used for surface treatment of metallic components with the aim of increasing surface toughness and extending fatigue life. The fatigue strength of the component can be improved by inducing compressive residual stress in the surface and subsurface layers by the shot peening process. Numerical simulation of the shot peening process is an important tool that is used to aid in understanding the effects of the process parameters on intended goal of attaining the optimum residual stress profile and maximum process gain. In this paper an elasto-plastic finite element model is used for the shot peening process. The process parameters that are varied in this analysis are: the shot diameter, shot speed, number of shots at a given time (coverage) and target material. The analysis is carried out for two different materials, namely, steel and aluminum. An Explicit finite element code (ABAQUS) is used to perform this task. These parameters have different effects on the resulting residual profile and the results of the study showed that by adjusting these parameters, the most effective residual stress profile could be obtained.

Reduced Rough-Surface Parametrization for Use With the Discrete-Element Model

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Stephen T. McClain ◽  
Jason M. Brown
Keyword(s):  
Heat Transfer ◽  
Rough Surface ◽  
Surface Characterization ◽  
Rough Surfaces ◽  
Roughness Element ◽  
Three Dimensional ◽  
Element Model ◽  
Discrete Element ◽  
Diameter Distribution ◽  
Discrete Element Model

The discrete-element model for flows over rough surfaces was recently modified to predict drag and heat transfer for flow over randomly rough surfaces. However, the current form of the discrete-element model requires a blockage fraction and a roughness-element diameter distribution as a function of height to predict the drag and heat transfer of flow over a randomly rough surface. The requirement for a roughness-element diameter distribution at each height from the reference elevation has hindered the usefulness of the discrete-element model and inhibited its incorporation into a computational fluid dynamics (CFD) solver. To incorporate the discrete-element model into a CFD solver and to enable the discrete-element model to become a more useful engineering tool, the randomly rough surface characterization must be simplified. Methods for determining characteristic diameters for drag and heat transfer using complete three-dimensional surface measurements are presented. Drag and heat transfer predictions made using the model simplifications are compared to predictions made using the complete surface characterization and to experimental measurements for two randomly rough surfaces. Methods to use statistical surface information, as opposed to the complete three-dimensional surface measurements, to evaluate the characteristic dimensions of the roughness are also explored.

scholarly journals Influence of residual stress profile and surface microstructure on fatigue life of a 15-5PH

2018 ◽  
Vol 213 ◽  
pp. 623-629 ◽  
Author(s):  
F. Valiorgue ◽  
V. Zmelty ◽  
M. Dumas ◽  
V. Chomienne ◽  
C. Verdu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Surface Microstructure ◽  
Stress Profile ◽  
Residual Stress Profile

scholarly journals Cross-Sectional Mapping of Residual Stresses by Measuring the Surface Contour After a Cut

2000 ◽  
Vol 123 (2) ◽  
pp. 162-168 ◽  
Author(s):  
M. B. Prime
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Stress Measurement ◽  
Superposition Principle ◽  
New Method ◽  
Contour Method ◽  
Stress Profile ◽  
Relaxation Methods ◽  
Cross Sectional ◽  
Residual Stress Profile

A powerful new method for residual stress measurement is presented. A part is cut in two, and the contour, or profile, of the resulting new surface is measured to determine the displacements caused by release of the residual stresses. Analytically, for example using a finite element model, the opposite of the measured contour is applied to the surface as a displacement boundary condition. By Bueckner’s superposition principle, this calculation gives the original residual stresses normal to the plane of the cut. This “contour method” is more powerful than other relaxation methods because it can determine an arbitrary cross-sectional area map of residual stress, yet more simple because the stresses can be determined directly from the data without a tedious inversion technique. The new method is verified with a numerical simulation, then experimentally validated on a steel beam with a known residual stress profile.

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