scholarly journals Mechanism of Blunt Punching Tools’ Influence on Deformation and Residual Stress Distribution

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2029
Author(s):  
Wei Wang ◽  
Xiang Fang ◽  
Xuanguo Wang ◽  
Michel Andrieux ◽  
Vincent Ji
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Magnetic Properties ◽  
High Efficiency ◽  
Local Deformation ◽  
Cutting Edge ◽  
Tensile Residual Stress ◽  
Iron Core ◽  
Machining Accuracy ◽  
Element Analysis

Punching is the main manufacturing process with high efficiency and machining accuracy used to produce the iron cores of motors. However, it usually introduces residual stress at the cutting edge and affects the magnetic properties of the iron core. Further studies show that the tensile residual stress (TRS) has a negligible effect on the magnetic properties, compared with the compressive stress. The blunt punch tools cause local TRS and the formation of local large plastic deformation (PD) at the cutting edge as the cost. The PD has a more serious effect on the magnetic properties of materials than TRS. Therefore, this study mainly focused on local deformation distribution and the associated microstructure evolution using EBSD (Electron Backscatter Diffraction) and finite element analysis; and the formation mechanism of tensile residual stress during the punching process at the cutting edge of a non-oriented silicon steel after punching with blunt tools, by using nanoindentation and a numerical simulation. The experimental results showed the existence of a specific bending area, a highly deformed area and a large burr at the cutting edge. These direct observations were confirmed with those obtained by the simulation model. Furthermore, the tensile residual stress on the surface was verified through nanoindentation tests and by a numerical simulation. The results indicate also that the formation of a tensile residual stress zone depends especially on the bending area formed during punching with blunt tools.

Numerical Simulation of Welding for Box Beam Structure on Bogie of High Speed Train

2011 ◽  
Vol 399-401 ◽  
pp. 1816-1819
Author(s):  
Huan Jun Liu ◽  
Jian Xin Liu ◽  
Hui Chen ◽  
Hua Ji ◽  
Zhi Yi Zhang
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
High Speed ◽  
Weathering Steel ◽  
Beam Structure ◽  
Element Analysis ◽  
Box Beam ◽  
Welding Sequence ◽  
Side Beam ◽  
Welding Sequences

In this paper a typical box beam structure on certain high speed power car was taken as study object, Based on the finite element analysis software SYSWELD, established the material parameters database for SMA490BW weathering steel, and performed the numerical simulation for the welding of typical box beam structure of side beam of high speed bogie, comparison between the simulation results and that of experiment test verified the existing welding procedures. For the purpose of studying the influence of welding sequence on the residual stress and providing theoretical support for actual production, the residual stress under different welding sequences was investigated then.

Numerical Simulation of Residual Stress Field Induced by Water-Jet Cavitation Peening

2013 ◽  
Vol 345 ◽  
pp. 312-315 ◽  
Author(s):  
Bing Han ◽  
Yan Hua Wang ◽  
Chang Liang Xu
Keyword(s):  
Numerical Simulation ◽  
Residual Stress ◽  
Stress Field ◽  
New Technology ◽  
Diffraction Method ◽  
Spring Steel ◽  
Water Jet ◽  
Material Surface ◽  
Residual Stress Field ◽  
Element Analysis

Water-jet cavitation peening is a new technology for surface modification of metallic materials. Compress residual stress layer is induced by impact wave pressure in the submerged cavitating jets processing. Based on ANSYS/LS-DYNA finite element analysis software, residual stress field in the SAE1070 spring steel material surface induced by cavitate-jet water peening process is simulated, the magnitude and variation rules of the residual stress along the layer depth under different conditions is obtained. In order to verify the correctness of the numerical simulation, the size and distribution of residual stress by the X-ray diffraction method. The results show that the numerical simulation and experimental results are well consistent.

Numerical Simulation on Efficient Spinning Technology Based on Multi-Point Adjusting Principle

2011 ◽  
Vol 189-193 ◽  
pp. 2993-2996
Author(s):  
Xue Peng Gong
Keyword(s):  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Plastic Deformation ◽  
Finite Element ◽  
Flexible Manufacturing ◽  
High Efficiency ◽  
Equivalent Stress ◽  
Experimental Result ◽  
Element Analysis ◽  
Fea Model

In order to realize high efficiency and flexible manufacturing for rotary surfaces, efficient spinning technology (EST) is researched. It is the combination of multi-point forming and traditional spinning. Principle of EST is described, traditional spinning method is compared with it, and characteristics of it are analyzed. Finite element analysis (FEA) model of disc-shape part is established, EST process is analyzed, equivalent stress and plastic strain distributions are analyzed. EST equipment is developed, and the experiments are made. Results indicate: EST process consists of four stages; equivalent stress in sheet metal’s center region and bendable rollers active region exceeds yield stress, and plastic deformation is generated; experimental result accords with simulation result. Feasibility of EST is validated by simulation and experimental results.

Mitigation of Welding-Induced Tensile Residual Stress at Surface of Heavy Section Plate by In-Process Control Welding With Trailing Heat Sink

2013 ◽  
Author(s):  
Shigetaka Okano ◽  
Masahito Mochizuki
Keyword(s):  
Residual Stress ◽  
Process Control ◽  
Heat Sink ◽  
Stress Measurement ◽  
Tensile Residual Stress ◽  
Low Carbon ◽  
Element Analysis ◽  
Heavy Section ◽  
Weld Residual Stress ◽  
Simulation Results

In this study, in-process control welding with a trailing heat sink was applied to mitigate the weld tensile residual stress at the surface of a heavy section plate of low-carbon austenitic stainless steel. The distribution of the weld residual stress at the surface of the plate was evaluated by X-ray stress measurement and finite element analysis. As the results, it was experimentally and analytically confirmed that the welding-induced tensile residual stress at the welded surface was mitigated by welding with a trailing heat sink. Also, the measurement and simulation results were in good agreement. Based on the simulation results, the mechanisms of mitigation of the residual stress by welding with a trailing heat sink were discussed. It was concluded that the mitigation of the weld residual stress is due to the inverted gradient of temperature from the welded surface to the deepest parts of the plate.

Rubber Composition–Properties Relationships during Tire Numerical Simulation and Design Optimization

2017 ◽  
Vol 45 (1) ◽  
pp. 71-84 ◽  
Author(s):  
Alexey Mazin ◽  
Alexander Kapustin ◽  
Mikhail Soloviev ◽  
Alexander Karanets
Keyword(s):  
Numerical Simulation ◽  
Design Optimization ◽  
Strain Tensor ◽  
General Purpose ◽  
Orthogonal Functions ◽  
Element Analysis ◽  
Time Investment ◽  
Footprint Analysis ◽  
Composition Properties ◽  
Nonlinear Elastic

ABSTRACT Numerical simulation based on finite element analysis is now widely used during the design optimization of tires, thereby drastically reducing the time investment in the design process and improving tire performance because it is obtained from the optimized solution. Rubber material models that are used in numerical calculations of stress–strain distributions are nonlinear and may include several parameters. The relations of these parameters with rubber formulations are usually unknown, so the designer has no information on whether the optimal set of parameters is reachable by the rubber technological possibilities. The aim of this work was to develop such relations. The most common approach to derive the equation of the state of rubber is based on the expansion of the strain energy in a series of invariants of the strain tensor. Here, we show that this approach has several drawbacks, one of which is problems that arise when trying to build on its basis the quantitative relations between the rubber composition and its properties. An alternative is to use a series expansion in orthogonal functions, thereby ensuring the linear independence of the coefficients of elasticity in evaluation of the experimental data and the possibility of constructing continuous maps of “the composition to the property.” In the case of orthogonal Legendre polynomials, the technique for constructing such maps is considered, and a set of empirical functions is proposed to adequately describe the dependence of the parameters of nonlinear elastic properties of general-purpose rubbers on the content of the main ingredients. The calculated sets of parameters were used in numerical tire simulations including static loading, footprint analysis, braking/acceleration, and cornering and also in design optimization procedures.

Finite Element Modeling for Steel Cord Analysis in Radial Tires

2013 ◽  
Vol 41 (1) ◽  
pp. 60-79 ◽  
Author(s):  
Wei Yintao ◽  
Luo Yiwen ◽  
Miao Yiming ◽  
Chai Delong ◽  
Feng Xijin
Keyword(s):  
Finite Element ◽  
High Efficiency ◽  
Force Measurement ◽  
Three Dimensional ◽  
Local Stress ◽  
Tension Force ◽  
Center Line ◽  
Element Analysis ◽  
Design Variables ◽  
Steel Cord

ABSTRACT: This article focuses on steel cord deformation and force investigation within heavy-duty radial tires. Typical bending deformation and tension force distributions of steel reinforcement within a truck bus radial (TBR) tire have been obtained, and they provide useful input for the local scale modeling of the steel cord. The three-dimensional carpet plots of the cord force distribution within a TBR tire are presented. The carcass-bending curvature is derived from the deformation of the carcass center line. A high-efficiency modeling approach for layered multistrand cord structures has been developed that uses cord design variables such as lay angle, lay length, and radius of the strand center line as input. Several types of steel cord have been modeled using the developed method as an example. The pure tension for two cords and the combined tension bending under various loading conditions relevant to tire deformation have been simulated by a finite element analysis (FEA). Good agreement has been found between experimental and FEA-determined tension force-displacement curves, and the characteristic structural and plastic deformation phases have been revealed by the FE simulation. Furthermore, some interesting local stress and deformation patterns under combined tension and bending are found that have not been previously reported. In addition, an experimental cord force measurement approach is included in this article.

Tail shapes lead to different propulsive mechanisms in the body/caudal fin undulation of fish

2020 ◽  
pp. 095440622096768
Author(s):  
Jialei Song ◽  
Yong Zhong ◽  
Ruxu Du ◽  
Ling Yin ◽  
Yang Ding
Keyword(s):  
Numerical Simulation ◽  
Aspect Ratio ◽  
High Efficiency ◽  
The Body ◽  
Caudal Fin ◽  
Fish Model ◽  
Swimming Efficiency ◽  
Simulation Results ◽  
Propulsive Mechanism ◽  
High Depth

In this paper, we investigate the hydrodynamics of swimmers with three caudal fins: a round one corresponding to snakehead fish ( Channidae), an indented one corresponding to saithe ( Pollachius virens), and a lunate one corresponding to tuna ( Thunnus thynnus). A direct numerical simulation (DNS) approach with a self-propelled fish model was adopted. The simulation results show that the caudal fin transitions from a pushing/suction combined propulsive mechanism to a suction-dominated propulsive mechanism with increasing aspect ratio ( AR). Interestingly, different from a previous finding that suction-based propulsion leads to high efficiency in animal swimming, this study shows that the utilization of suction-based propulsion by a high- AR caudal fin reduces swimming efficiency. Therefore, the suction-based propulsive mechanism does not necessarily lead to high efficiency, while other factors might play a role. Further analysis shows that the large lateral momentum transferred to the flow due to the high depth of the high- AR caudal fin leads to the lowest efficiency despite the most significant suction.

scholarly journals Impact of residual stress evoked by pyramidal embossing on the magnetic material properties of non-oriented electrical steel

2021 ◽  
Author(s):  
Ines Gilch ◽  
Tobias Neuwirth ◽  
Benedikt Schauerte ◽  
Nora Leuning ◽  
Simon Sebold ◽  
...  
Keyword(s):  
Magnetic Material ◽  
Residual Stress ◽  
Magnetic Flux ◽  
Material Properties ◽  
Electrical Steel ◽  
Maximum Energy ◽  
Material Behavior ◽  
Electrical Machine ◽  
Element Analysis ◽  
Steel Sheets

AbstractTargeted magnetic flux guidance in the rotor cross section of rotational electrical machines is crucial for the machine’s efficiency. Cutouts in the electrical steel sheets are integrated in the rotor sheets for magnetic flux guidance. These cutouts create thin structures in the rotor sheets which limit the maximum achievable rotational speed under centrifugal forces and the maximum energy density of the rotating electrical machine. In this paper, embossing-induced residual stress, employing the magneto-mechanical Villari effect, is studied as an innovative and alternative flux barrier design with negligible mechanical material deterioration. The overall objective is to replace cutouts by embossings, increasing the mechanical strength of the rotor. The identification of suitable embossing geometries, distributions and methodologies for the local introduction of residual stress is a major challenge. This paper examines finely distributed pyramidal embossings and their effect on the magnetic material behavior. The study is based on simulation and measurements of specimen with a single line of twenty embossing points performed with different punch forces. The magnetic material behavior is analyzed using neutron grating interferometry and a single sheet tester. Numerical examinations using finite element analysis and microhardness measurements provide a more detailed understanding of the interaction of residual stress distribution and magnetic material properties. The results reveal that residual stress induced by embossing affects magnetic material properties. Process parameters can be applied to adjust the magnetic material deterioration and the effect of magnetic flux guidance.

scholarly journals Optimization Study of Post-Weld Heat Treatment for 12Cr1MoV Pipe Welded Joint

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 127
Author(s):  
Zichen Liu ◽  
Xiaodong Hu ◽  
Zhiwei Yang ◽  
Bin Yang ◽  
Jingkai Chen ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Residual Stress ◽  
Stress Reduction ◽  
Simulation Method ◽  
Post Weld Heat Treatment ◽  
Residual Stress Field ◽  
Element Analysis ◽  
Tempering Treatment ◽  
Temper Heat Treatment ◽  
Weld Heat

In order to clarify the role of different post-weld heat treatment processes in the manufacturing process, welding tests, post-weld heat treatment tests, and finite element analysis (FEA) are carried out for 12C1MoV steel pipes. The simulated temperature field and residual stress field agree well with the measured results, which indicates that the simulation method is available. The influence of post-weld heat treatment process parameters on residual stress reduction results is further analyzed. It is found that the post weld dehydrogenation treatment could not release residual stress obviously. However, the residual stress can be relieved by 65% with tempering treatment. The stress relief effect of “post weld dehydrogenation treatment + temper heat treatment” is same with that of “temper heat treatment”. The higher the temperature, the greater the residual stress reduction, when the peak temperature is at 650–750 °C, especially for the stress concentration area. The longer holding time has no obvious positive effect on the reduction of residual stress.

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