scholarly journals Experimental and Numerical Investigations of a Novel Laser Impact Liquid Flexible Microforming Process

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 599 ◽  
Author(s):  
Fei Liu ◽  
Huixia Liu ◽  
Chenkun Jiang ◽  
Youjuan Ma ◽  
Xiao Wang

A novel high strain rate microforming technique, laser impact liquid flexible embossing (LILFE), which uses laser induced shock waves as an energy source, and liquid as a force transmission medium, is proposed by this paper in order to emboss three-dimensional large area micro arrays on metallic foils and to overcome some of the defects of laser direct shock microembossing technology. The influences of laser energy and workpiece thickness on the deformation characteristics of the pure copper foils with the LILFE process were investigated through experiments and numerical simulation. A finite element model was built to further understand the typical stages of deformation, and the results of the numerical simulation are consistent with those achieved from the experiments. The experimental and simulation results show that the forming accuracy and depth of the embossed parts increases with the increase in laser energy and decrease in workpiece thickness. The thickness thinning rate of the embossed parts increases with the decrease of the workpiece thickness, and the severest thickness thinning occurs at the bar corner region. The experimental results also show that the LILFE process can protect the workpiece surface from being ablated and damaged, and can ensure the surface quality of the formed parts. Besides, the numerical simulation studies reveal the plastic strain distribution of embossed microfeatures under different laser energy.

2011 ◽  
Vol 70 ◽  
pp. 315-320 ◽  
Author(s):  
Riaz Muhammad ◽  
Agostino Maurotto ◽  
Anish Roy ◽  
Vadim V. Silberschmidt

Analysis of the cutting process in machining of advanced alloys, which are typically difficult-to-machine materials, is a challenge that needs to be addressed. In a machining operation, cutting forces causes severe deformations in the proximity of the cutting edge, producing high stresses, strain, strain-rates and temperatures in the workpiece that ultimately affect the quality of the machined surface. In the present work, cutting forces generated in a vibro-impact and hot vibro-impact machining process of Ti-based alloy, using an in-house Ultrasonically Assisted Turning (UAT) setup, are studied. A three-dimensional, thermo-mechanically coupled, finite element model was developed to study the thermal and mechanical processes in the cutting zone for the various machining processes. Several advantages of ultrasonically assisted turning and hot ultrasonically assisted turning are demonstrated when compared to conventional turning.


2020 ◽  
Vol 103 (4) ◽  
pp. 003685042096785
Author(s):  
Jianguo Duan ◽  
Qinglei Zhang ◽  
Xintao Long ◽  
Kebin Zhang

Semi-built-up crankshafts are universally manufactured by shrink-fitting process with induction heating device. The configurations of induction coil have a great impact on the distributions of eddy current and temperature of crankthrows. Most induction devices are apt to cause some undesirable phenomena such as uneven temperature distribution and irregular deformation after induction heating. This article proposes a modified configuration of induction heating coil according to the crankthrow geometry. By combining the heat conduction equation and the heat boundary conditions, a three-dimensional finite element model, which takes into account the nonlinearity of the material’s electromagnetic and thermal physical properties in the heating process, was developed. The influence of several parameters, such as position and curvature of the arc coil, the current frequency and density, coaxiality of crankweb hole and coil, influencing the temperature distribution inside the crankthrow was also analyzed. The comparison with the numerical simulation results of the original configuration indicates that the modified configuration has better adaptability to the crankthrow. Also, it can help to improve the temperature distribution, and reduce the deformation of the shrink-fitting hole. This exploration provide an effective way for the enterprise to further enhance the shrink-fitting quality of crankshaft.


2014 ◽  
Vol 490-491 ◽  
pp. 644-648
Author(s):  
Lian Cheng Li ◽  
Ming Zhe Li ◽  
Yuan Ting Li

in this paper, we mainly introduce the principle of the flexible blank drawer forming (FBDF), and establish the limited element model of the FBDF process. Then we make a numerical analysis on the hemispherical parts, and study the effect made on the result of shaping by damping force, friction coefficient as well as material parameter in per unit area. Through the analysis of the numerical simulation result, we can conclude that the greater the yield limit and elasticity modulus, the larger blank drawer force is required to form the shape; the more smooth the material surface, the less resistance to deformation will have. All this contributes to good quality of forming parts.


2013 ◽  
Vol 423-426 ◽  
pp. 972-977
Author(s):  
Lei Qin ◽  
Yan Ting Ma ◽  
Chang Jie Luo

In order to solve the problem of low accuracy of honeycomb semi-cell structures which are rolled by traditional trapezoidal tooth profile gear shaping rollers, conjugate trapezoidal tooth profile gear shaping rollers have been put forward to improve the quality of honeycomb semi-cell structures, basing on the theoretical analysis. Using ANSYS/LS-DYNA, a finite element model of rolling aluminum foils by two kinds of tooth profile shaping rollers was set up. Then results of numerical simulation indicate that the honeycomb semi-cell structures rolled by the conjugate trapezoidal gear shaping rollers are closer to the ideal size than those rolled by the traditional trapezoidal gear shaping rollers.


2012 ◽  
Vol 562-564 ◽  
pp. 1373-1376
Author(s):  
Shi Min Xu ◽  
Hua Gui Huang ◽  
Deng Yue Sun

A new manufacturing method of spiral hot bending process for the end sheet of tubular pile was introduced in this paper. A three-dimensional (3-D) thermal-mechanical coupled elastic-plasticity finite element model was setup to simulate the hot bending process, and then, the section deformation mechanism from hot bar by rolling to the end sheet has been investigated from the simulation results. The industry manufacture conditions show that the efficiency and quality has been highly improved by the spiral hot bending process. The thickness variety along the radial direction of the workpiece has also been analyzed, the moment and force during the hot bending was also presented in this paper. These conclusions obtained can guide for the forming technology making for both the end sheet of tubular pile and other ring parts.


2014 ◽  
Vol 496-500 ◽  
pp. 452-455
Author(s):  
Chi Chih Shen

A three dimensional numerical simulation model of metal rolling formation is developed from the theoretical model. In this theoretical model, the two variables of element deformation and temperature variation are placed in a variable matrix. The thermal elastic plastic rigid matrix and heat transfer rigid matrix are placed in the same expansion rigid matrix. Furthermore, the numerical simulation analytical model developed in this paper was used to simulate aluminum strip rolling.


2014 ◽  
Vol 501-504 ◽  
pp. 111-114
Author(s):  
Ling Xia Gao ◽  
Xiang Jun Yang ◽  
Li Kun Qin

Three-dimensional non-linearity finite element model of shield tunnel was established on basis of the Z1 line of Tianjin subway. And then it was applied to simulate construction process of shield tunnel. Surface settlement of the tunnel during the construction was obtained. The settlement data of transverse and longitudinal direction from numerical simulation were fitted through a polynomial expression. Then a contrastive analysis of curves from numerical simulation and matching formulae were made. The result shows that it is feasible to utilize the empirical formulas like Pecks to predict surface settlement in Tianjin caused by shield construction.


2010 ◽  
Vol 154-155 ◽  
pp. 1472-1475
Author(s):  
Xiang Jie Wang ◽  
Jian Zhong Cui ◽  
Hai Tao Zhang

The rules of the distribution of magnetic field were carried out by numerical simulation. The distribution of magnetic field was got, and the effects of current intensity and frequency on the distribution of magnetic field were analyzed by constructing three-dimensional finite element model and using ANSYS software which is a kind of commercial FEM analysis software. The results show that the intensity of magnetic field is proportional to current intensity, magnetic field is mainly localized in the surface region of liquid melt and there is a notable edge effect in the corner.


2011 ◽  
Vol 291-294 ◽  
pp. 269-272
Author(s):  
Ying Wu Lan ◽  
Zhong Yi Cai ◽  
Ming Zhe Li

The deformation of sheet metal in the continuous flexible forming (CFF) process is complex and the formed result is affected by many factors. In this paper, the finite element model of CFF was founded and the forming processes of spherical parts were simulated with the software ABAQUS. The interaction between transversal deformation and longitudinal deformation in the CFF process is analyzed. Based on results of numerical simulation and forming tests, the process parameters of CFF is revised, and formed surface is measured by three dimensional sensing system, the measured results indicate the precision of formed parts are satisfactory.


2015 ◽  
Vol 32 (3) ◽  
pp. 518-527 ◽  
Author(s):  
Jacob Berg ◽  
Nikola Vasiljevíc ◽  
Mark Kelly ◽  
Guillaume Lea ◽  
Michael Courtney

AbstractThis paper presents an analysis of mean wind measurements from a coordinated system of long-range WindScanners. From individual scan patterns the mean wind field was reconstructed over a large area, and hence it highlights the spatial variability. From comparison with sonic anemometers, the quality of the WindScanner data is high, although the fidelity of the estimated vertical velocity component is significantly limited by the elevation angles of the scanner heads. The system of long-range WindScanners presented in this paper is close to being fully operational, with the pilot study herein serving not only as a proof of concept but also verifying expectations of reliable wind measurements over arbitrary three-dimensional volumes, in future sustained meteorological campaigns.


Sign in / Sign up

Export Citation Format

Share Document