scholarly journals Multi-Pass Stamping Forming a Concave Ring

2020 ◽  
Vol 10 (18) ◽  
pp. 6434
Author(s):  
Song Zhang ◽  
Xuedao Shu ◽  
Jianan Shi ◽  
Zixuan Li
Keyword(s):  
Process Parameters ◽  
Strain Field ◽  
Structural Characteristics ◽  
Production Quality ◽  
Experimental Results ◽  
Stress And Strain ◽  
Dimensional Error ◽  
Stamping Dies ◽  
Key Factor

To improve the production quality and efficiency of the concave ring, a multi-pass stamping technology is used to replace the spinning technology to form the concave ring. First, the multi-pass stamping dies are designed according to the structural characteristics of the concave ring. Then, the process parameters are determined based on the bending conditions and the dimensional requirements of the concave ring. Next, the rationality of the designed stamping dies is verified by analyzing the stress and strain field of the multi-pass stamping concave ring. Finally, the stamping experiments are carried out. Experimental results show that the dimensional error of the concave ring formed by multi-pass stamping is less than 0.5%. The multi-pass stamping technology is feasible to form the concave ring. The reasonable design of the mold is the key factor to prevent defects in the workpiece. The concave ring formed by multi-pass stamping meets the industrial requirements.

Investigation on the Improvement of Magnetic Properties by Hot Deformation Processes for NdFeB Magnets

2014 ◽  
Vol 626 ◽  
pp. 317-322 ◽  
Author(s):  
Yen Ju Chen ◽  
Chao Cheng Chang ◽  
Po Jen Hsiao ◽  
Can Xun Chang
Keyword(s):  
Plastic Deformation ◽  
Magnetic Properties ◽  
Strain Rate ◽  
Process Parameters ◽  
Effective Strain ◽  
High Energy ◽  
Experimental Results ◽  
Ndfeb Magnets ◽  
Energy Product ◽  
Key Factor

Traditionally, NdFeB magnets with high remanent flux density or high energy product could only be manufactured through altering the material compounds. In recent years, studies indicated that the magnet properties of NdFeB magnets could be improved through plastic deformation. These studies pointed out that the degree of plastic deformation is a key factor to improve magnetic properties. However, there are still many other process parameters that could affect the magnetic properties either positively or negatively. In this paper, process parameters such as strain, strain rate, and temperature are studied to illustrate their influences on the magnetic properties of NdFeB magnets. The magnetic property could be greatly improved when the preferred orientation appears on the microstructure of deformed NdFeB magnets. One of the experimental results showed that the energy product value had been increased by 76.7% when the effective strain value had reached 0.65. Experimental results also showed that strain rate is a dominating factor with regard to the flow stress of material. Through a proper combination of these parameters, one can obtain NdFeB magnets with their magnetic properties greatly improved.

Simulation Study and Optimization of Process Parameters in Precision Forming of the Nut Plate

2012 ◽  
Vol 602-604 ◽  
pp. 1878-1882
Author(s):  
Xiang Bei Wang ◽  
Duo Nian Yu ◽  
Hong Yan Chang
Keyword(s):  
Finite Element ◽  
Field Distribution ◽  
Process Parameters ◽  
Strain Field ◽  
Constitutive Relationship ◽  
Stress And Strain ◽  
Forming Process ◽  
Forming Quality ◽  
Metal Material ◽  
Damage And Fracture

For researching the stress and strain field distribution and the effect of process parameters on forming quality in the precision forming process of mid-thick nut plate, this paper builds the nut plate 3d parts of precise forming finite element entity model in ABAQUS software, and then uses Johnson-cook model to describe the material constitutive relationship and metal material damage and fracture. The ALE adaptive technology has been used to control material large deformation in finite-element analysis of elastic-plastic. Based on this model, this paper analyzes the stress and strain field distribution,average pressure stress distribution and metal material plastic flow rates distribution, and the influence of the process parameters on the forming quality in the forming process.

scholarly journals Physico-Chemical and In Vitro Characterization of Chitosan-Based Microspheres Intended for Nasal Administration

Pharmaceutics ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 608
Author(s):  
Csilla Bartos ◽  
Patrícia Varga ◽  
Piroska Szabó-Révész ◽  
Rita Ambrus
Keyword(s):  
Drug Delivery ◽  
Spray Drying ◽  
Process Parameters ◽  
Sodium Tripolyphosphate ◽  
Structural Characteristics ◽  
Nasal Administration ◽  
Drug Bioavailability ◽  
Intranasal Application ◽  
Spray Dried

The absorption of non-steroidal anti-inflammatory drugs (NSAIDs) through the nasal epithelium offers an innovative opportunity in the field of pain therapy. Thanks to the bonding of chitosan to the nasal mucosa and its permeability-enhancing effect, it is an excellent choice to formulate microspheres for the increase of drug bioavailability. The aim of our work includes the preparation of spray-dried cross-linked and non-cross-linked chitosan-based drug delivery systems for intranasal application, the optimization of spray-drying process parameters (inlet air temperature, pump rate), and the composition of samples. Cross-linked products were prepared by using different amounts of sodium tripolyphosphate. On top of these, the micrometric properties, the structural characteristics, the in vitro drug release, and the in vitro permeability of the products were studied. Spray-drying resulted in micronized chitosan particles (2–4 μm) regardless of the process parameters. The meloxicam (MEL)-containing microspheres showed nearly spherical habit, while MEL was present in a molecularly dispersed state. The highest dissolved (>90%) and permeated (~45 µg/cm2) MEL amount was detected from the non-cross-linked sample. Our results indicate that spray-dried MEL-containing chitosan microparticles may be recommended for the development of a novel drug delivery system to decrease acute pain or enhance analgesia by intranasal application.

scholarly journals A FEA Method for Mathematical Calculation and Prediction Analysis Cross-sectional Ovalization of Tubes under Rotary Straightening

2021 ◽  
Vol 2083 (4) ◽  
pp. 042057
Author(s):  
Ziqian Zhang ◽  
Ying Zhong
Keyword(s):  
Process Parameters ◽  
Element Model ◽  
Simulation Method ◽  
Stress And Strain ◽  
Cross Sectional ◽  
Bending Deformation ◽  
Deformation Stage ◽  
Thin Walled Pipe ◽  
Thin Walled ◽  
Flattening Process

Abstract The section flattening phenomenon (namely Bazier effect) will occur in the large bending deformation stage of thin-walled pipe in the continuous straightening process. The maximum section flattening amount and the residual section flattening amount are important process parameters, which are the basis for calculating the subsequent process parameters of the flattening circle, and directly determine the roundness of the final pipe and the product quality. However, it is hard to be obtained by the theoretical or experimental methods. Therefore, based on the structure and process parameters of the leveler, a finite element model was built to simulate the section flattening process. Then, ANSYS/LS-DYNA software was used to dynamically simulate the bending flattening phenomenon of thin-walled pipe in the continuous straightening process, and the stress and strain nephographic of the flattening deformation zone was obtained. By recording the position curve of the key nodes in the preventing process, the section flattening amount of the thin-walled pipe in the large bending deformation stage in the continuous straightening process was determined. The simulation results show that the dynamic simulation method can effectively predict the section flattening of thin-walled pipe in the process of continuous straightening.

Kalman Filtering for Seam Tracking in Master-Slave Robot Remote Welding System

2011 ◽  
Vol 314-316 ◽  
pp. 1005-1008
Author(s):  
Hong Tang Chen ◽  
Hai Chao Li ◽  
Hong Ming Gao ◽  
Lin Wu
Keyword(s):  
Kalman Filtering ◽  
Seam Tracking ◽  
Experimental Results ◽  
Welding Quality ◽  
Welding Seam ◽  
Tracking Process ◽  
Key Factor ◽  
Remote Welding ◽  
Welding System

Welding seam tracking precision is a key factor influencing welding quality for master-slave robot remote welding system. However, it does not satisfy the welding requirement due to significant noises. To eliminate the influence of noises upon the seam tracking precision and improve the seam tracking precision, a master-slave robot remote welding system was built and Kalman filtering (KF) was applied to the seam tracking process. The experimental results show that the KF eliminated the influence of noises upon the seam tracking precision and improved the seam tracking precision.

Numerical Investigation for Performance Enhancement of Photovoltaic Cell by Nanofluid Cooling

2022 ◽  
pp. 1-32
Author(s):  
Hassan Salem ◽  
Ehab Mina ◽  
Raouf Abdelmessih ◽  
Tarek Mekhail
Keyword(s):  
Heat Transfer ◽  
Particle Size ◽  
Single Phase ◽  
Performance Enhancement ◽  
Photovoltaic Cell ◽  
System Optimization ◽  
Experimental Results ◽  
Key Factor ◽  
Discrete Phase ◽  
Frame Work

Abstract The cooling fluid is a key factor in cooling photovoltaic (PV) panels especially in the case of concentrated irradiance. Maintaining the panel at low temperature increases its efficiency. This paper investigates the usage of water-Al2O3 as a nanofluid for achieving the required cooling process. The particle concentrations and sizes are investigated to record their effect on heat transfer and pressure drop in the developing and developed regions. The research was performed using ANSYS CFD software with two different approaches: the single phase with average properties, and the discrete phase with the Eulerian-Lagrangian frame-work. Both approaches are compared to experimental results found in the literature. Both approaches show good agreement with the experimental results, with some advantage for the single-phase model both in processing time and in predicting heat transfer in the concentration range of 1-6% by volume. It was shown that, the heat transfer coefficient is greatly enhanced by increasing the particle concentration or decreasing the particle size. On the other hand, the usage of nanofluid causes a severe increase in the pumping power, especially with the increase in concentration and the reduction in particle size. Thus, a system optimization was suggested in order to raise the overall system efficiency for photovoltaic applications.

Experimental Evaluation of Glob-top Materials for use in Harsh Environments

2005 ◽  
Vol 2 (4) ◽  
pp. 253-268 ◽  
Author(s):  
Mats Lindgren ◽  
Ilja Belov ◽  
Peter Leisner
Keyword(s):  
Process Parameters ◽  
Experimental Evaluation ◽  
Experimental Results ◽  
Polymer Materials ◽  
Harsh Environments ◽  
Automotive Applications ◽  
Critical Material ◽  
Material Evaluation

This article presents results of experimental evaluation of glob-top materials for multi-chip-modules (MCM) in harsh environments. Material and process tests have been performed with the purpose to find a material which would fulfill the reliability requirements for use e.g. in military or automotive applications. Seven polymer materials, i.e. four epoxies, two silicones and one polyurethane material have been selected and evaluated in the experiments. The most critical material and process parameters for glob-top have been identified and measured. Based on the experimental results, application-based scoring of studied epoxy materials has been performed. Material evaluation results have been summarized in conclusions about the most suitable glob-top material for use in harsh environments.

scholarly journals Optimization of FCAW Parameters for Ferrite Content in 2205 DSS Welds Based on the Taguchi Design Method

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Tianqi Li ◽  
Yingying Zhang ◽  
Lei Gao ◽  
Yunhao Zhang
Keyword(s):  
Mathematical Model ◽  
Process Parameters ◽  
Welding Speed ◽  
Design Method ◽  
Welding Current ◽  
Taguchi Design ◽  
Experimental Results ◽  
Ferrite Content ◽  
Welding Parameters ◽  
Torch Angle

This study presents the Taguchi design method with L9 orthogonal array which was carried out to optimize the flux-cored arc welding (FCAW) process parameters such as welding current, welding voltage, welding speed, and torch angle with reference to vertical for the ferrite content of duplex stainless steel (DSS, UNS S32205) welds. The analysis of variance (ANOVA) was applied, and a mathematical model was developed to predict the effect of process parameters on the responses. The results indicate that welding current, welding voltage, welding speed, torch angle with reference to vertical, and the interaction of welding voltage and welding speed are the significant model terms connected with the ferrite content. The ferrite content increases with the increase of welding speed and torch angle with reference to vertical, but decreases with the increase of welding current and welding voltage. Through the developed mathematical model, the target of 50% ferrite content in weld metal can be obtained when all the welding parameters are set at the optimum values. Finally, in order to validate experimental results, confirmation tests were implemented at optimum working conditions. Under these conditions, there was good accordance between the predicted and the experimental results for the ferrite content.

scholarly journals Numerical Modelling of Stress/Strain Field Arising in Diamond-Impregnated Cobalt

2014 ◽  
Vol 59 (2) ◽  
pp. 443-446 ◽  
Author(s):  
J. Borowiecka-Jamrozek ◽  
J. Lachowski
Keyword(s):  
Strain Field ◽  
Diamond Crystal ◽  
Metallic Matrix ◽  
Stress And Strain ◽  
Stress Strain ◽  
Strain Fields ◽  
Matrix Potential ◽  
The Matrix ◽  
Saw Blade ◽  
Diamond Retention

Abstract The paper presents results of computer simulations of the stress/strain field built up in a cobalt matrix diamond impregnated saw blade segment during its fabrication and after loading the protruding diamond with an external force. The main objective of this work was to create better understanding of the factors affecting retention of diamond particles in a metallic matrix of saw blade segments, which are produced by means of the powder metallurgy technology. The effective use of diamond impregnated tools strongly depends on mechanical and tribological properties of the matrix, which has to hold the diamond grits firmly. The diamond retention capability of the matrix is affected in a complex manner by chemical or mechanical interactions between the diamond crystal and the matrix during the segment manufacture. Due to the difference between the thermal expansion coefficients of the diamond and metallic matrix, a complex stress/strain field is generated in the matrix surrounding each diamond crystal. It is assumed that the matrix potential for diamond retention can be associated with the amount of the elastic and plastic deformation energy and the size of the deformation zone occurring in the matrix around diamonds. The stress and strain fields generated in the matrix were calculated using the Abaqus software. It was found that the stress and strain fields generated during segment fabrication change to a large extent as the diamond crystal emerges from the cobalt matrix to reach its working height of protrusion.

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