Numerical simulation of ultrasonic spot welding of superelastic NiTi alloys: Temperature distribution and deformation behavior

2022 ◽  
pp. 1-30
Author(s):  
Yuxin Wang ◽  
Sansan Ao ◽  
Wei Zhang ◽  
Anqi Wang ◽  
Mingpeng Cheng ◽  
...  
Keyword(s):  
Thermal Stress ◽  
Stress Distribution ◽  
Spot Welding ◽  
Welding Process ◽  
Temperature History ◽  
Niti Shape Memory Alloy ◽  
Analysis Model ◽  
Element Analysis ◽  
Simulation Results ◽  
Cu Interlayer

Abstract Ultrasonic spot welding (USW) has attracted increasing attention due to its high- throughput solid-state bonding mechanism, which shows great potential in the semiconductor and automotive industry for the joining of metal sheets. However, the short welding cycle makes it challenging to effectively monitor the temperature history and deformation of the workpieces during the USW process, especially for the materials with some special properties. In this study, a three-dimensional (3D) finite element analysis model for USW of superelastic NiTi shape memory alloy (SMA) with Cu interlayer was developed using ANSYS Workbench. The thermal-stress coupled phenomena including the heat generation and stress distribution during the welding process was simulated and analyzed. Firstly, the superelastic constitutive model of NiTi SMAs was constructed. The distribution of temperature and stress field was then obtained by thermal-stress analysis using the direct coupling method, and the superelasticity of SMAs was observed. The simulation results showed that the highest temperature occurred in the center of the welding area during USW, which is proportional to the welding time and inversely proportional to the clamping pressure. In addition, the maximum stress occurred at the center of the contact surface between upper NiTi and Cu interlayer. After that, the validity of the simulation results was verified by setting up a thermocouple temperature measurement platform to collect the temperature data, which exhibited a good agreement with the simulated results. The simulation procedure demonstrates its potential to predict temperature and stress distribution during USW process.

Finite Element Analysis Model and Residual Stress Optimization in Rotor Welding Process

2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Zhufeng Liu ◽  
Yonghui Xie ◽  
Hao Dang
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Thermal Strain ◽  
Welding Process ◽  
Optimization Method ◽  
Mechanical Analysis ◽  
Analysis Model ◽  
Element Analysis ◽  
Stress Optimization

Abstract In this paper, the finite element method (FEM) is conducted for thermal and mechanical analysis of a half 2D axisymmetric welded rotor model. The temperature results after welding are obtained and supported by the experiment results. Furthermore, the thermal strain and residual stress of the weld are analyzed in detail by considering solid-state phase transformation (SSPT). Besides, parametric optimization method is adopted to optimize the region of large stress distribution. By choosing the weld pass number as the optimized parameter, the area decreases by 5.4% when the optimal pass number is 18. The axial and hoop stress distributions are obtained at the inner and outer surfaces near the weld for the better stress distribution.

Finite Element Analysis of Thermal Stress Distribution in Planar SOFC

2019 ◽  
Vol 7 (1) ◽  
pp. 1977-1986 ◽  
Author(s):  
Chih-Kuang Lin ◽  
Tsung-Ting Chen ◽  
An-Shin Chen ◽  
Yau-Pin Chyou ◽  
Lieh-Kwang Chiang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Stress ◽  
Stress Distribution ◽  
Element Analysis ◽  
Thermal Stress Distribution

scholarly journals Biomechanical assessment of different fixation methods in mandibular high sagittal oblique osteotomy using a three-dimensional finite element analysis model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Charles Savoldelli ◽  
Elodie Ehrmann ◽  
Yannick Tillier
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Three Dimensional ◽  
Von Mises Stress ◽  
Analysis Model ◽  
Element Analysis ◽  
Fixation Methods ◽  
Oblique Osteotomy ◽  
Von Mises

AbstractWith modern-day technical advances, high sagittal oblique osteotomy (HSOO) of the mandible was recently described as an alternative to bilateral sagittal split osteotomy for the correction of mandibular skeletal deformities. However, neither in vitro nor numerical biomechanical assessments have evaluated the performance of fixation methods in HSOO. The aim of this study was to compare the biomechanical characteristics and stress distribution in bone and osteosynthesis fixations when using different designs and placing configurations, in order to determine a favourable plating method. We established two finite element models of HSOO with advancement (T1) and set-back (T2) movements of the mandible. Six different configurations of fixation of the ramus, progressively loaded by a constant force, were assessed for each model. The von Mises stress distribution in fixations and in bone, and bony segment displacement, were analysed. The lowest mechanical stresses and minimal gradient of displacement between the proximal and distal bony segments were detected in the combined one-third anterior- and posterior-positioned double mini-plate T1 and T2 models. This suggests that the appropriate method to correct mandibular deformities in HSOO surgery is with use of double mini-plates positioned in the anterior one-third and posterior one-third between the bony segments of the ramus.

FE Modeling of Stress Distribution in MAO Coating on TC4 Substrate under Thermal Shock Cyclic Loading

2014 ◽  
Vol 941-944 ◽  
pp. 1629-1632 ◽  
Author(s):  
Ye Sheng Zhong ◽  
Li Ping Shi ◽  
Ming Wei Li ◽  
Jia Yu ◽  
Jian Han Liang ◽  
...  
Keyword(s):  
Shear Stress ◽  
Thermal Stress ◽  
Stress Distribution ◽  
Adhesive Strength ◽  
Thermal Cycle ◽  
Radial Stress ◽  
Numerical Study ◽  
Element Analysis ◽  
Solid Element ◽  
Cycle Loading

A numerical study using finite element analysis (FEA) was performed to investigate the thermal, shear and radial stresses developed in MAO coating on substrate of TC4 under thermal cycle loading. The four-node quadrilateral thermal solid element PLANE55 and four-node quadrilateral structural solid element PLANE42 with axisymmetric option was used to model the temperature distribution and thermal stress field of the MAO coating on TC4 substrates. The thermal stress, radial stress and shear stress along the thickness in film/substrate system are analyzed systematically under different thermal cycle loading. It is found that the thermal stress of MAO coating exhibits a linear relationship with thickness of substrate, but it exhibit a parabolic relationship with the thickness of the coating. The radial stress and shear stress distribution of the coating–substrate combination are also calculated. It is observed that high tensile shear stress of MAO coating on TC4 substrate reduces its adhesive strength but high-compressive shear stress improves its adhesive strength.

Simulating Thermoelectric Effect and Its Impact on Asymmetric Weld Nugget Growth in Aluminum Resistance Spot Welding

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Lin Deng ◽  
YongBing Li ◽  
Wayne Cai ◽  
Amberlee S. Haselhuhn ◽  
Blair E. Carlson
Keyword(s):  
Resistance Spot Welding ◽  
Spot Welding ◽  
Weld Nugget ◽  
Thermoelectric Effects ◽  
Element Analysis ◽  
Resistance Spot ◽  
Seebeck Coefficients ◽  
Nugget Growth ◽  
Simulation Results ◽  
The Impact

Abstract Resistance spot welding (RSW) of aluminum–aluminum (Al–Al) is known to be very challenging, with the asymmetric growth of the weld nugget often observed. In this article, a semicoupled electrical–thermal–mechanical finite element analysis (FEA) procedure was established to simulate the RSW of two layers of AA6022-T4 sheets using a specially designed Multi-Ring Domed (MRD) electrodes. Critical to the modeling procedure was the thermoelectric (including the Peltier, Thomson, and Seebeck effects) analyses to simulate the asymmetric nugget growth in the welding stage. Key input parameters such as the Seebeck coefficients and high-temperature flow stress curves were measured. Simulation results, experimentally validated, indicated that the newly developed procedure could successfully predict the asymmetric weld nugget growth. Simulation results also showed the Seebeck effect in the holding stage. The simulations represent the first quantitative investigation of the impact of the thermoelectric effects on resistance spot welding.

Numerical simulation of the metal inert gas welding process that considers grain heterogeneity

2020 ◽  
pp. 146442072094991
Author(s):  
Chang Li ◽  
Zhengwei Chen ◽  
Hexin Gao ◽  
Dacheng Zhang ◽  
Xing Han
Keyword(s):  
Thermal Stress ◽  
Stress Distribution ◽  
Thermal Stresses ◽  
Statistical Significance ◽  
Voronoi Tessellation ◽  
Welding Process ◽  
Vertical Direction ◽  
Inert Gas ◽  
Mechanical Coupling ◽  
Metal Inert Gas Welding

It is of great significance to reveal the microevolution mechanism of welded structures during thermo-mechanical coupling to improve the welding quality. In this paper, a random microcrystalline structure model for welds is established by the Voronoi tessellation method. According to the nanoindentation results, heterogeneous grains are produced. A welding workpiece model with statistical significance is established. On this basis, the Python script and the birth and death element method are used to realize the transient growth of a weld, and a thermo-mechanical coupling model for the SUS301L-HT stainless steel metal inert gas welding process is established. The temperature field and thermal stress field are calculated. The calculation shows that the thermal stresses along the growth direction of the weld area are in the form of a “trapezoid,” and the stresses at both ends are small. The stress in the vertical direction of the weld has a single peak, and the peak appears in the center of the weld. The stress distribution of the model that considers heterogeneous grains is obviously inhomogeneous compared with that of the traditional model. The thermal stress distribution in the weldment is obviously inhomogeneous due to the heterogeneous grains, the stresses at the boundaries of the adjacent grains in the weldment change abruptly. It is found that the greater the difference in the mechanical properties between grains is, the more obvious the change.

Finite Element Analysis of Effects of Preheating and Postweld Heat Treatment on Residual Stress in Pipe Welding

2011 ◽  
Vol 314-316 ◽  
pp. 428-431 ◽  
Author(s):  
Hui Du ◽  
Dong Po Wang ◽  
Chun Xiu Liu ◽  
Hai Zhang
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Finite Element ◽  
Stress Distribution ◽  
Welding Process ◽  
Postweld Heat Treatment ◽  
Element Model ◽  
Element Analysis ◽  
Pipe Welding ◽  
Postweld Heat

To simulate preheating and postweld heat treatment of Q345 steel pipe welding, the finite element model was established. The welding process was simulated by method of the ANSYS element birth and death technique. In this paper, to obtain the distribution of the temperature field and stress field in different situations, preheating processes with two different values of temperature and postweld heat treatment process were simulated respectively. The results show that preheating can homogenize residual stress distribution of the weldment and decrease the residual stress. The heat treatment reduces the residual stress in inner and outer walls by 24% and 70% respectively and the stress distribution is more even and stress concentration is reduced.

Coupling Analysis of Frictional Heat under Control of Disc Brake Anti-Skid Brake System

2011 ◽  
Vol 199-200 ◽  
pp. 721-728
Author(s):  
Yi Bing Zhang ◽  
Ying Ying Zhang
Keyword(s):  
Thermal Stress ◽  
Friction Pair ◽  
Brake System ◽  
Frictional Heat ◽  
Brake Disc ◽  
Analysis Model ◽  
Element Analysis ◽  
Study Results ◽  
Friction Temperature ◽  
Braking Force

The nonlinearity of material properties at different temperatures and the manner of braking force applying on a brake system are two key factors to affect the coupling of temperature and thermal stress. Considering these two factors, a finite element analysis model of automobile brake disc and pad is established. By using the model, the dynamic frictional heat and thermal stress of braking friction pair could be simulated and the coupling characters of temperature and thermal stress on friction surfaces could be studied, where the braking force is constant or controlled by an anti-skid brake system(ABS). The study results shown that the friction temperature of brake disk rises in periodic and fluctuant tendency. The fluctuant increase of temperature will influence the character of braking. The increase of friction temperature between a brake disc and pad can decrease under the control of ABS, so the effect of thermo-mechanical coupling could be reduced.

Numerical Analysis of the Dynamic Interaction Between Pantograph and Overhead Contact Line Using FEM

2011 ◽  
Author(s):  
Sung Pil Jung ◽  
Tae Won Park ◽  
Jin Hee Lee
Keyword(s):  
Numerical Analysis ◽  
Contact Line ◽  
Dynamic Interaction ◽  
Fe Analysis ◽  
Contact Forces ◽  
Analysis Program ◽  
Analysis Model ◽  
Element Analysis ◽  
Simulation Results ◽  
Analysis Models

This study aims to create a numerical analysis model which can investigate the interaction between pantograph and overhead contact line used for railway vehicles, and validate the simulation results according to EN 50318 standards. Finite element analysis models of pantograph and overhead contact line are created using SAMCEF, a commercial FE analysis program, and mean, standard deviation, maximum and minimum values of contact forces are obtained. The simulation results are validated according to EN 50318, and the reliability of SAMCEF as an analysis solver of railway vehicle’s catenary system is discussed.

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