scholarly journals Stability Analysis of Steel Welded Tubes Forming Process Using Numerical Simulations

2021 ◽  
Vol 15 (2) ◽  
pp. 298-304
Author(s):  
Marko Delić ◽  
Vesna Mandić ◽  
Marko Popović
Keyword(s):  
Influencing Factors ◽  
Numerical Experiments ◽  
Hard Metal ◽  
Outer Diameter ◽  
Forming Process ◽  
Tube Forming ◽  
Welded Tube ◽  
Optimal Values ◽  
Geometrical Factors ◽  
The Stability

In this paper, the research results of the stability of steel welded tubes forming process are presented. The aim of this research is to determine influence of geometrical and tribological parameters on stability of the process and to determine optimal values of influential process parameters. A research plan with variation of influential parameters was made, on the basis of which experimental and numerical experiments were performed. Tube forming was performed in one operation in a two-part tool made of hard metal by a combination of widening and narrowing. The geometrical factors observed during experiments are length, outer diameter and thicknesses of steel welded tube as a billet. Friction conditions in contact between tool and tubular workpiece are considered in two cases, the first one when standard machine oil is used as a lubricant and the second one when tube billet surface is phosphated. Based on results of experiments, influencing factors on stability of tube forming process were analysed and optimal production technology was recommended, including optimal values of influencing factors. Results obtained by experimental research were confirmed through numerical experiments based on finite element method.

Tube Buckling: An Advantage to Tube Shaping

2018 ◽  
Author(s):  
Chetan P. Nikhare
Keyword(s):  
Tube Hydroforming ◽  
Rigid Bodies ◽  
Outer Diameter ◽  
Forming Process ◽  
Tube Forming ◽  
Strength Coefficient ◽  
Tube Shape ◽  
Tube Flaring ◽  
Hydroforming Process ◽  
Proper Consideration

Tube forming is one of the most common manufacturing processes to shape the tubes. Within tube forming operations the general practice is to expand and reduce the tube end cross-section and bend the tube by means of a solid mandrel. Mostly the mandrel is rigid bodies. To reduce the friction between the tube and the tool, tube hydroforming process was evolved in which the fluid was highly pressurized to expand the tube shape to the desired shape. By reducing the friction more uniform thickness could be achieved and thus increase in formability. One of the process within tube end forming process is flaring which is the focus of this paper. In tube flaring process the conical shape rigid tool flares the end of the tube. While flaring the tube, the tube buckles if proper consideration would not have been taken. In this paper, various influencing parameters such as outer diameter to tube thickness ratio, length or the tube, the strength coefficient of the tube and conical angle of the tool were analyzed. It was noted that the most important factor affect the buckling of the tube is its strength coefficient. Considering this parameter the buckling was carried out in a set die and a tube shape was formed. The advantages of this process over similar processes were discussed.

scholarly journals Cold Forging Effect on the Microstructure of Motorbike Shock Absorbers Fabricated by Tube Forming in a Closed Die

2021 ◽  
Vol 11 (5) ◽  
pp. 2142
Author(s):  
Trung-Kien Le ◽  
Tuan-Anh Bui
Keyword(s):  
Material Flow ◽  
Cold Forging ◽  
Technological Parameters ◽  
Forming Process ◽  
Tube Forming ◽  
Shock Absorbers ◽  
Thin Walled Tube ◽  
Thin Walled ◽  
Quality Of Products ◽  
Forming Defects

Motorbike shock absorbers made with a closed die employ a tube-forming process that is more sensitive than that of a solid billet, because the tube is usually too thin-walled to conserve material. During tube forming, defects such as folding and cracking occur due to unstable tube forming and abnormal material flow. It is therefore essential to understand the relationship between the appearance of defects and the number of forming steps to optimize technological parameters. Based on both finite element method (FEM) simulations and microstructural observations, we demonstrate the important role of the number and methodology of the forming steps on the material flow, defects, and metal fiber anisotropy of motorbike shock absorbers formed from a thin-walled tube. We find limits of the thickness and height ratios of the tube that must be held in order to avoid defects. Our study provides an important guide to workpiece and processing design that can improve the forming quality of products using tube forming.

COMPUTING AN ADAPTIVE MESH IN FLUID PROBLEMS USING NEURAL NETWORK AND GENETIC ALGORITHM WITH ADAPTIVE RELAXATION

2008 ◽  
Vol 17 (06) ◽  
pp. 1089-1108 ◽  
Author(s):  
NAMEER N. EL. EMAM ◽  
RASHEED ABDUL SHAHEED
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Numerical Experiments ◽  
Back Propagation ◽  
Adaptive Mesh ◽  
Learning System ◽  
Back Propagation Algorithm ◽  
Adaptive Smoothing ◽  
Different Types ◽  
Optimal Values

A method based on neural network with Back-Propagation Algorithm (BPA) and Adaptive Smoothing Errors (ASE), and a Genetic Algorithm (GA) employing a new concept named Adaptive Relaxation (GAAR) is presented in this paper to construct learning system that can find an Adaptive Mesh points (AM) in fluid problems. AM based on reallocation scheme is implemented on different types of two steps channels by using a three layer neural network with GA. Results of numerical experiments using Finite Element Method (FEM) are discussed. Such discussion is intended to validate the process and to demonstrate the performance of the proposed learning system on three types of two steps channels. It appears that training is fast enough and accurate due to the optimal values of weights by using a few numbers of patterns. Results confirm that the presented neural network with the proposed GA consistently finds better solutions than the conventional neural network.

The Stability of Potassium Ferrate in Water

2014 ◽  
Vol 881-883 ◽  
pp. 215-218
Author(s):  
Kai Luo ◽  
Gang Cao ◽  
Ming Yu Li ◽  
Gang Ren
Keyword(s):  
Influencing Factors ◽  
Potassium Ferrate ◽  
The Stability

The influencing factors of the stability for the potassium ferrate (K2FeO4), including pH, alkalinity, O3, KI, KClO3, KCl, NaClO3and Na2SiO3, were studied in this work. The results showed that the K2FeO4stability in water is best at about pH=10. The higher the alkalinity is, the stronger of K2FeO4stability would be. The O3had no effect to improve the K2FeO4stability. The K2FeO4stability would be best in water with 15mmol/L NaClO3, 10mmol/L Na2SiO3and 9mol/L alkalinity. Under this condition, the K2FeO4content would be 83.28% after 24h.

scholarly journals SPECTRA OF THERMOSTIMULATED DEPOLARIZATION OF BIOCOMPOSITES WITH FILLERS OF BIOLOGICAL ORIGIN

2021 ◽  
Vol 5 (1(82)) ◽  
pp. 45-49
Author(s):  
E. Gojayev ◽  
V. Salimova ◽  
Sh. Alieva
Keyword(s):  
Surface Density ◽  
Fish Bone ◽  
Fish Scales ◽  
Biological Origin ◽  
Space Charges ◽  
High Pressure Polyethylene ◽  
Optimal Values ◽  
The Stability ◽  
Thermally Stimulated Depolarization ◽  
Volumetric Content

The paper presents the results of studying the spectra of thermally stimulated depolarization of high-pressure polyethylene modified with fillers of biocomposites with fillers of biological origin - fish bone and fish scales. It was revealed that the stability and surface density of space charges can be controlled by varying the volumetric content of biological fillers. The optimal values of bio-fillers that contribute to the stability of the surface density of the studied biocomposites have been determined.

scholarly journals Numerical Study on Phase-Fitted and Amplification-Fitted Diagonally Implicit Two Derivative Runge-Kutta Method for Periodic IVPS

2021 ◽  
Vol 50 (6) ◽  
pp. 1799-1814
Author(s):  
Norazak Senu ◽  
Nur Amirah Ahmad ◽  
Zarina Bibi Ibrahim ◽  
Mohamed Othman
Keyword(s):  
Fourth Order ◽  
Initial Value Problems ◽  
Numerical Experiments ◽  
Numerical Study ◽  
Kutta Method ◽  
Initial Value ◽  
First Order ◽  
Runge Kutta Method ◽  
Runge Kutta ◽  
The Stability

A fourth-order two stage Phase-fitted and Amplification-fitted Diagonally Implicit Two Derivative Runge-Kutta method (PFAFDITDRK) for the numerical integration of first-order Initial Value Problems (IVPs) which exhibits periodic solutions are constructed. The Phase-Fitted and Amplification-Fitted property are discussed thoroughly in this paper. The stability of the method proposed are also given herewith. Runge-Kutta (RK) methods of the similar property are chosen in the literature for the purpose of comparison by carrying out numerical experiments to justify the accuracy and the effectiveness of the derived method.

scholarly journals Research on the influencing factors of family firm innovation

2021 ◽  
Vol 235 ◽  
pp. 02017
Author(s):  
Yingrui Liu
Keyword(s):  
Influencing Factors ◽  
Family Involvement ◽  
Family Business ◽  
External Environment ◽  
Family Firm ◽  
Economic Activities ◽  
Firm Innovation ◽  
Strategic Focus ◽  
The Stability ◽  
Innovation Behavior

Family business plays an important role in the world’s economic activities, and has made great contributions to the stability and development of the economy of various countries. Innovation is an important but inexplicable part of the strategic focus of family business. Based on the existing literature, this paper discusses the factors that influence the innovation behavior of enterprises from the perspective of family involvement and external environment.

Prediction of Deformations of Steel Plate by GEP in Forming Process

2012 ◽  
Vol 544 ◽  
pp. 268-273
Author(s):  
Lei Yang ◽  
Liang Gao
Keyword(s):  
Mathematical Model ◽  
Influencing Factors ◽  
Steel Plate ◽  
Heating Process ◽  
Forming Process ◽  
Line Heating ◽  
Main Method ◽  
Plate Deformation ◽  
Final Deformation

Line heating is the main method for forming compound curved shells of hull. The accuracy of final deformation and the productivity depend on the experience of the workers. To predict the plate deformation, the explicit mathematical model for deformation and the main influencing factors by FEA and GEP is established in this paper. The main influencing factors in line heating process were analyzed firstly. Then, 16 group deformation results of steel plate under the five main influencing factors were obtained by FEA. At last, the explicit mathematical model for deformation and the main influencing factors was established.

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