Residual Stress Analysis Research Articles

Joining of graphite to electrical pure iron using AgCuTi filler alloy and analysis of residual stress within the brazed joint

Joining of graphite to electrical pure iron using AgCuTi filler alloy and analysis of residual stress within the brazed joint

Residual stress analysis of TC4/Inconel718 functionally graded material produced by laser additive manufacturing based on progressive activation element method

Residual stress analysis of TC4/Inconel718 functionally graded material produced by laser additive manufacturing based on progressive activation element method

Experimental and Numerical Analysis of Residual Stresses in Similar and Dissimilar Welds of T91 and Super304H Steel Tubes

Experimental and Numerical Analysis of Residual Stresses in Similar and Dissimilar Welds of T91 and Super304H Steel Tubes

On the three‐dimensional numerical analysis of residual stresses on two scales in hot bulk forming parts

AbstractCurrent research focuses on the induction of residual stresses in a component during its manufacturing process, which shows a significant impact on the final component's properties. During the manufacturing of a hot bulk forming component, the temperature evolution allows to influence the resulting residual stress state efficiently and purposefully. Following the characterization of residual stresses on different scales, single‐scale finite element simulations are carried out on macro‐ and microscale. In contrast to previous findings for two‐dimensional boundary value problems, the effects of the third dimension are demonstrated. Furthermore, it is shown that the residual stress distribution is effectively influenced by choosing different cooling routes in targeted manner. Eventually, the importance of microscopic residual stress investigations is discussed.

Analysis of Residual Stresses in Spot Cooled Vibration Assisted Turning of Ti6Al4V Alloy using Computational Fluid Dynamics-Aided Finite Element Method

Analysis of Residual Stresses in Spot Cooled Vibration Assisted Turning of Ti6Al4V Alloy using Computational Fluid Dynamics-Aided Finite Element Method

Finite Element Simulation and Residual Stress Analysis of the Whole Process of Metal Bellows Forming

Finite Element Simulation and Residual Stress Analysis of the Whole Process of Metal Bellows Forming

Numerical analysis and experimental investigation of residual stress and properties of T-joint by a novel in-situ laser shock forging and arc welding

A novel technique, referred to as Weld-LSF, has been proposed for the low-stress manufacturing of T-joints through in-situ synchronous assisted arc welding, employing laser shock forging. This innovative process introduces plastic deformation in the deposited weld seam at elevated temperatures, effectively reducing the tensile residual stresses (TRS) associated with welding. The thermal-mechanical coupling finite element model for Weld-LSF has been established, combining the classical bar-frame model and the inherent strain theory. The mechanism behind achieving low-stress welding of T-joints through in-situ LSF has been analyzed. Subsequently, experimental investigations were conducted using Q345 base metal and ER60–5 welding wire to study the influence of in-situ LSF on the microstructure and mechanical properties of the specimens. The results demonstrate that by introducing in-situ LSF at higher temperatures in the weld seam, tensile residual stresses are transformed from high to low levels, with the average TRS reduced from 342 MPa to 185 MPa, representing a significant reduction of 45.9 %. In-situ LSF forms a hardened layer with a depth of approximately 0.5 mm on the surface of the weld seam, albeit with certain depth limitations. Furthermore, the in-situ LSF treatment addresses the issue of poor ductility caused by stress concentration at the weld toe of T-joints, achieving a desirable combination of strength and ductility. The feasibility of in-situ LSF technology in welding fabrication has been established. In comparison to traditional welding techniques, the in-situ LSF treatment offers promising prospects for achieving low-stress welding, thereby enhancing the mechanical performance and fatigue life of the welding process.

Effect of ultrasonic rolling on crack propagation behavior of Ti6Al4V titanium alloy laser welded joints

This study investigated the effect of ultrasonic rolling on the fatigue resistance of Ti6Al4V titanium alloy laser welded joints, with an emphasis on crack growth rate. Multiple analyses were conducted on samples subjected to different numbers of rolling passes, including analysis of surface roughness, morphology, cross-section structure, hardness, fatigue fracture, and residual stress. Ultrasonic rolling was found to considerably enhance the life cycle of the sample. One, three, and five rolling passes resulted in fatigue life increases of 17.14%, 46.38%, and 66.61%, respectively, when compared with untreated samples. Treated samples exhibited rough and intricate crack propagation paths on fracture surfaces, along with numerous secondary cracks. Fatigue striation width decreased by 48.6%, 62.5%, and 69.4% for samples receiving one, three, and five rolling passes, respectively. These fatigue striations, which were narrower and more densely distributed, indicate that ultrasonic rolling effectively increases fatigue life. The ultrasonic rolling treatment enhanced fatigue performance and reduced the rate of crack propagation due to changes in surface compressive residual stress, microstructure, microhardness, and improved surface quality. Crack retardation primarily occurred in initial stage of crack propagation and stable propagation stages, whereas inhibitory effects weakened during the final fracture stage due to superposition and offset of the higher driving force with compressive residual stress. In summary, the study demonstrates that treatment via ultrasonic rolling is an effective method for improving fatigue life and fracture toughness in Ti6Al4V titanium alloy laser-welded joints.

Analysis of residual stresses in cutting tools coated via physical vapour deposition: A review

Physical vapour deposition (PVD) method is a popular method to deposit thin layers. Hence, it is widely used to fabricate coated cutting tools. In the current article, brief review of the investigations related to the residual stress induced during PVD process is presented. The investigative reports on the factors influencing the magnitude and nature of the residual stress are analysed. Also, the reports which presented the effects of the residual stress on the mechanical properties and cutting performances are analysed and included in this article.

Developed numerical Analysis of Residual Stress caused by Welding and Cutting in Steel Structures

AbstractThe welding and flame‐cutting process in the steel construction are commonly used, especially for the bridge structure. Some experiments about welding and cutting have been done separately by some researchers. The results from the experiments were also compared with the results from the numerical simulation under 3D or 2D models. The agreements between those results are as good as they predicted. Therefore, the numerical simulation is a better way to analyze the quality of the steel construction after welding and cutting without time‐consuming and a large amount of cost. But there are only a few research about the numerical simulation and the some of them are aimed to verify the experiments. In this study, the calculation about the residual stresses after welding and thermo‐cutting are considered from 3D‐model into 2D‐Model. The heat source model is simply regarded as curves of time and welding energy with the algorithm methods. And no matter the change of the parameters of the model and the heat source, the heat transfer and the residual stresses can be calculated with the 2D models as fast as possible. By the means of the finite element software Abaqus, the I‐profiles are easy to receive the job results with the input parameters. The influence of the welding and cutting process are visual and direct.

Analytical and finite element investigation on residual stress analysis for composite thermoplastic cantilever beam under unique load

For a steel-fiber-based low-density homogenous composite thermoplastic cantilever beam, numerical (ANSYS APDL19) and analytical (MATLAB program) for elastoplastic stress distributions are achieved. At its free end, a thermoplastic cantilever structural member is loaded using a steady force. For orientation angles of (0°, 15°, 30°, 45°, 60°, 75° and 90°), the yield region's expansion and (σx)r are calculated. MATLAB program was used to determine the residual distribution of stress analytically. Both the yield zone that expands just at the top surface and the plastic zone that expands on both the top and bottom surfaces simultaneously are subjected to the elastic–plastic analysis. After the applied load has been freed, the components of residual distribution of stress are detected. Additionally, the distributions of the σx residual stress is established. By utilizing residual distribution of stress, the beam can be reinforced. The upper and lower edges of the beam are where the residual stress values are strongest. For the same load in the beam at orientation angles of (0°, 15°, 30°, 45°, 60°, 75° and 90°) the space amidst the free end and the plastically contracted region is determined. Lower discrepancy is evaluated for numerical (ANSYS APDL19) and analytical results.

An analysis of longitudinal residual stresses in EN AW-5083 alloy strips as a function of cold-rolling process parameters

Abstract Various process nonhomogeneities in the cold rolling lead to an uneven distribution of deformation across the strip cross-section, resulting in the induction of residual stresses. This study investigates the longitudinal residual stresses in cold-rolled EN AW-5083 aluminum alloy strips using the finite element method (FEM) to achieve reliable predictions. The impacts of process parameters, including the reduction ratio, coefficient of contact friction, and front and back tensions, were analyzed. Changes in residual stresses, depending on the process parameters, were determined by the distribution of linear and shear strains, as well as the strain hardening conditions at the exit part of the deformation zone. An increase in the reduction ratio from 20 to 50%, as well as an increase in the friction coefficient from 0.1 to 0.2, resulted in decreased stress values. The residual stresses on the strip surface, determined by the experimental deflection method, were consistent with the results obtained by FEM simulation. Under the impact of back and/or front tensions, there is a reduction in longitudinal residual stresses, with the front tension exerting the greatest influence. The research results show that the FEM is a reliable tool for predicting residual stresses in cold-rolled strips.

Simultaneous Optimization of Surface Roughness and Mechanical Properties of 316L Produced by LB–PBF Using Grey Relational Analysis Complemented by Residual Stress Analysis

Simultaneous Optimization of Surface Roughness and Mechanical Properties of 316L Produced by LB–PBF Using Grey Relational Analysis Complemented by Residual Stress Analysis

Flatness Enhancement of Metal-Supported Solid Oxide Fuel Cells with Additional Compensation Layer

Solid oxide fuel cells are high-temperature fuel cells which offer several advantages: high efficiency, fuel flexibility, high-quality waste heat, and the use of non-noble metal catalysts. Metal-supported solid oxide fuel cells, in which the ceramic mechanical support layer is replaced with the metal support, are considered as next-generation solid oxide fuel cells because of their enhanced mechanical/thermal ruggedness compared to conventional ceramic-supported solid oxide fuel cells. However, different thermomechanical behavior of metal support and ceramic layers during sintering makes metal-supported cells vulnerable to warping. Cell warpage must be minimized because it reduces not only uniformity of wet-chemical coating, but also actual contact area between electrode and interconnect, increasing the contact resistance.In this study, causes of metal-supported cell warpage are identified, and the design that can minimize cell warpage is suggested for successful scale-up of metal-supported solid oxide fuel cells. Through thermomechanical and residual stress analyses, it is found that residual stress derived from coefficient of thermal expansion mismatch between electrode layers and the metal substrate is the main cause of the warpage of metal-supported solid oxide fuel cells. Based on these results, a novel design that has thicker metal protection layer on the opposite side of the electrolyte is proposed for minimizing cell warpage due to residual stress. Through the design modification, vertical deformation of 2-inch metal-supported solid oxide fuel cell can be successfully controlled to 17.36% of the previous design. Furthermore, electrochemical evaluation showed a 21% decrease in ohmic ASR and a 25% increase in peak power density after the design modification, implicating reduction of contact resistance as a result of increased contact area by enhanced flatness.

Finite element analysis and experimental verification of residual stress in brazed diamond with Ni-Cr filler alloy

Residual stress is the main factor affecting the processing performance and service life of brazed diamond tools. Due to the high melting point of Ni-Cr filler alloy, the difference in thermal expansion coefficient between diamond and brazing layer is large during high brazing temperature, and excessive residual stress tends to be generated at the brazed joint. The existing process parameters are difficult to meet the demand for the lower residual stress under high brazing temperature. Suppressing effectively excessive residual stress has become the focus of current researches for process optimization of brazed diamond. In this paper, the conventional spherical finite element model of diamond is replaced by a six-octahedral finite element model of diamond, and a 3D finite element model of brazed diamond is established. The effects of brazing temperature, brazing layer thickness and holding time on the residual stresses in brazed diamond are analyzed. The results show that higher brazing temperatures result in larger differences in thermal expansion coefficients between the diamond and brazing layer, resulting in larger residual stress. The higher brazing layer thickness will enlarge the stress affected area inside diamond and thus generate higher stress. The residual stress decreases with rising holding time, however, the subsequent thermal damage to the diamond increases. Experimental measured tendency of residual stress for brazed diamond through Raman spectroscopy is well consistent with that of calculated results. After observing of the surface morphology for brazed diamond through super-depth of field microscope, the brazed diamond presents the low residual stress, weak graphitization and excellent processing performance at the condition of brazing temperature of 1010 °C, brazing layer thickness of 0.3 mm and holding time of 5 min.

Quantification and Analysis of Residual Stresses in Braking Pedal Produced via Laser-Powder Bed Fusion Additive Manufacturing Technology.

This study focuses on the experimental verification of residual stress (RS) in a 3D-printed braking pedal using the Powder Bed Fusion (PBF) method with SS316L material. The RS was measured at two representative locations using the hole drilling method (HDM) and the dividing method, which are semi-destructive and destructive methods of RS measurement, respectively. The finite element method (FEM) was used with Ansys Workbench 2020R2 and Simufact Additive 2021 software to determine the magnitude of RS. The results provide insights into how RS is incorporated into metal 3D-printed components and the available tools for predicting RS. This information is essential for experts to improve the accuracy and functionality of SLM parts when post-subtractive or additive manufacturing processes are used. Overall, this study contributes to the advancement of knowledge on the effects of RS on 3D-printed metal components, which can inform future research and development in this area.

A comparative assessment of the effects of laser shock peening and ultrasonic shot peening on surface integrity and ratcheting fatigue performance of HSLA steel

In this work, a comparative assessment of the effects of laser shock peening (LSP) and ultrasonic shot peening (USP) on surface integrity and ratcheting fatigue performance of ASTM A588 Grade D high strength low alloy steel was done. Surface roughness, microhardness, microstructure, residual stress, and micro-texture analyses were used to describe the unpeened and peened surfaces. Three sets of tension-compression asymmetric cyclic loading tests were carried out at room temperature on unpeened and peened specimens to evaluate the effects of the applied treatment on strain accumulation and fatigue life. The quantitative dislocation densities of selected specimens were calculated in order to examine the mechanism underlying the softening behavior of USP-treated specimens during fatigue testing. The results are presented in light of the substantial surface roughness, lower compressive residual stress, and weakening of texture intensity revealing an unexpectedly large drop in fatigue strength following USP treatment compared to the unpeened and laser-peened specimens.

Analysis of laser welding on dissimilar materials with the influence of adding interlayer

The laser welding of dissimilar materials poses several challenges in practical applications, such as molten pool instability, the formation of intermetallic compounds (IMCs), and cracking caused by differential thermal stresses. In this study, we investigated the impact of incorporating a nickel (Ni) foil as an intermediate layer on lap joints of dissimilar materials (SS304 and Al6061) welded using the continuous laser welding (CLW) technique. The thermomechanical simulation accurately predicted the width and depth of SS304–Ni–Al6061 joints, with deviations of merely 3.92% and 19.04% from experimental results, respectively. Residual stress analysis revealed that the addition of a nickel foil reduced residual stress in the heat-affected zone (HAZ) and improved joint fatigue life. Furthermore, the incorporation of 0.1 and 0.2 mm Ni foils enhanced joint strength and effectively suppressed the formation of brittle intermetallic compounds, resulting in a remarkable maximum lap shear force of up to 1026 N. The simulation results for the shear load-displacement curve displayed excellent agreement with experimental data, with a deviation of only 6%. Notably, joints with the Ni foil demonstrated a greater ability to prevent crack formation caused by thermal expansion mismatch compared to joints without the Ni foil. The Ni interlayer served as a diffusion barrier and stress buffer, promoting a more uniform microstructure and reducing the likelihood of crack formation in bonded materials. Overall, this study comprehensively investigates the impact of incorporating a nickel interlayer on laser-welded lap joints of dissimilar materials. The findings offer valuable insights for practical applications, enabling improved joint strength, reliability, and crack resistance in laser welding dissimilar materials.

Optimization of FEM models for welding residual stress analysis using the modal method

Optimization of FEM models for welding residual stress analysis using the modal method

Residual stress associated with crystalline phase transformation of 3–6 mol% yttria-stabilized zirconia ceramics induced by mechanical surface treatments

Monolithic dental prostheses made of 3–6 mol% yttria-stabilized zirconia (3–6YSZ) have gained popularity owing to their improved material properties and semi-automated fabrication processes. In this study, we aimed to evaluate the influence of mechanical surface treatments, such as polishing, grinding, and sandblasting, on the residual stress of 3–6YSZ used for monolithic prostheses in association with crystalline phase transformation. Plate specimens were prepared from five dental zirconia blocks: Aadva Zirconia ST (3YSZ), Aadva Zirconia NT (6YSZ), Katana HT (4YSZ), Katana STML (5YSZ), and Katana UTML (6YSZ). The specimens were either polished using 1, 3, or 9 μm diamond suspensions, ground using 15, 35, or 55 μm diamond discs, or sandblasted at 0.2, 0.3, or 0.4 MPa. The residual stress, crystalline phase, and hardness were analyzed using the cosα method, X-ray diffraction (XRD), and Vickers hardness test, respectively. Additionally, we analyzed the residual stress on the surfaces of monolithic zirconia crowns (MZCs) made of 4YSZ, 5YSZ, and 6YSZ, which were processed using clinically relevant procedures, including manual grinding, followed by polishing using a dental electric motor on the external surface, and sandblasting on the internal surface. Residual stress analysis demonstrated that grinding and sandblasting, particularly the latter, resulted in the generation of compressive residual stress on the surfaces of the plate specimens. XRD revealed that the ground and sandblasted specimens contained a larger amount of the rhombohedral phase than that of the polished specimens, which may be a cause of the residual stress. Sandblasting significantly increased the Vickers hardness compared to polishing, which may possibly be due to the generation of compressive residual stress. In the case of MZCs, compressive residual stress was detected not only on the sandblasted surface, but also on the polished surface. The difference in the residual stress between the plate and crown specimens may be related to the force applied during the automated and manual grinding and polishing procedures. Further studies are required to elucidate the effects of the compressive residual stress on the clinical performance of MZCs.