The Numerical Simulation of Hemispherical Parts Based on FBDF Technology

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.

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.


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.


2010 ◽  
Vol 148-149 ◽  
pp. 1171-1176
Author(s):  
Ju Hua Huang ◽  
Li Xian Li ◽  
Ying Ying Wan ◽  
Jun Tuan Guo

This paper takes the rear axle cap which is a typical automobile covering part as the research object. 3D and finite element model of it are built, and the drawing process is simulated with Dynaform, then the technological parameters are analyzed and optimized based on the simulation results, finally the part is compared with the one that is processed in practice. The results show that this method is easy and feasible, it not only increase the work efficiency greatly but also improve the quality of products.


2013 ◽  
Vol 319 ◽  
pp. 468-473
Author(s):  
Li Juan Xu ◽  
An Cui ◽  
Qiang Yang

With the increasing application of lightweight multi-materials in vehicle body, the SPR (self-piercing riveting)with half-hollow rivet is used to connect hybrid metals due to its simple operation and reliable connection. In this paper, appropriate size parameters of half-hollow rivet and die are selected according to sheets’ thickness after the determination of hybrid metal materials, namely FAS2205 dual phase steel, AA2036 aluminum alloy, AA7050 aluminum alloy, AA6061 aluminum alloy and 460E high strength steel. The finite element model of SPR with half-hollow rivets is constructed and the accuracy of which is proved by comparing with the experiment in the relative reference. What’s more, the Johnson-Cook constitutive model is taken as material model to simulate the plastic and hardening behaviors during riveting process. The influence on joint quality of the strength matching of rivet/bottom sheet is studied through numerical simulation and direct observation, and the relationship schematic diagram between them is gained. Meanwhile, the riveting joints at several uniform loading velocities are simulated and the quality of which are analyzed. The research results show that the appropriate matching of rivet to the bottom sheet strength is a key prerequisite for joint quality and the punch velocity plays an important role on the riveting joint quality and efficiency of assembly.


2010 ◽  
Vol 20-23 ◽  
pp. 1397-1400 ◽  
Author(s):  
Wei Hua Kuang ◽  
Biao Biao Chen

Much progress has achieved in forging technology, and it has become a popular process for preparation of intricate parts. As a case, a finite element model of the square block forging process was established by DEFORM software. The deformation, distribution and development trend of velocity, mean stress, equivalent strain and equivalent strain rate were predicted. The load-time variation curves in X, Y and Z direction were obtained too. Based on the numerical simulation result, we had a better understanding of the forging process.


Author(s):  
A.V. Konstantinovich ◽  
◽  
A.S. Kuracheva ◽  
E.D. Binkevich

In conditions of climate change, when temperature and precipitation fluctuations occur more and more frequently during the growing season, it is necessary to obtain high quality seedlings with "immunity" to various stress factors, including high weediness, the damage from which is associated with a decrease in yield (by 25 -35%) and with a deterioration in the quality of agricultural products. Due to the imbalance in production technology, seedlings are often weakened, overgrown, with a low yield per unit area and survival rate in the field. One of the solutions to this problem is the use of PP for pre-sowing seed treatment to increase the competitiveness of seedlings in the field.


2013 ◽  
Vol 652-654 ◽  
pp. 2450-2454
Author(s):  
Zhi Hong Zhang ◽  
Guo Guang Cheng

The paper describes multi-section round bloom casting using external MEMS, equipped with max section D600mm and min D280mm mold, the center line of D280mm mold not coincident with the axis of stirrer coils. it is exist eccentric electromagnetic stirring of mold which section less than max D600mm, a mathematical model of MEMS has been established, the index of central segregation of D280mm macrostructure had decreased less than 1.12 by optimized parameters of electromagnetic stirring and SEN immerse depth, in the end, the quality of round bloom had improved.


2021 ◽  
pp. 014459872110135
Author(s):  
Zhen Tian ◽  
Shuangxi Jing ◽  
Lijuan Zhao ◽  
Wei Liu ◽  
Shan Gao

The drum is the working mechanism of the coal shearer, and the coal loading performance of the drum is very important for the efficient and safe production of coal mine. In order to study the coal loading performance of the shearer drum, a discrete element model of coupling the drum and coal wall was established by combining the results of the coal property determination and the discrete element method. The movement of coal particles and the mass distribution in different areas were obtained, and the coal particle velocity and coal loading rate were analyzed under the conditions of different helix angles, rotation speeds, traction speeds and cutting depths. The results show that with the increase of helix angle, the coal loading first increases and then decreases; with the increase of cutting depth and traction speed, the coal loading rate decreases; the increase of rotation speed can improve the coal loading performance of drum to a certain extent. The research results show that the discrete element numerical simulation can accurately reflect the coal loading process of the shearer drum, which provides a more convenient, fast and low-cost method for the structural design of shearer drum and the improvement of coal loading performance.


Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3206
Author(s):  
Xuehui Chen ◽  
Xin Xu ◽  
Wei Liu ◽  
Lei Huang ◽  
Hao Li ◽  
...  

This paper studies the compound effect of liquid medium and laser on the workpiece and analyses the law of material surface temperature change during the processing. Taking 7075-T6 aluminum alloy as the research object, the surface temperature field of aluminum alloy processed using water-jet-assisted laser machining under different process parameters was simulated using finite element software. In addition, the temperature field of the material surface was detected in real-time using the self-built water-jet-assisted laser machining temperature field detection system, and the processing results were observed and verified using an optical microscope, scanning electron microscope, and energy spectrum analyzer. The results show that when the water jet inflow angle is 45°, the heat-affected area of the material surface is the smallest, and the cooling effect of the temperature field of the material surface is better. Considering the liquidus melting point of 7075 aluminum alloys, it is concluded that the processing effect is better when the water jet velocity is 14 m·s−1, the laser power is 100 W, and the laser scanning speed is 1.2 mm·s−1. At this time, the quality of the tank is relatively good, there are no cracks in the bottom of the tank, and there is less slag accumulation. Compared with anhydrous laser etching, water-jet-assisted laser etching can reduce the problems of micro-cracks, molten slag, and the formation of a recast layer in laser etching and improve the quality of the workpiece, and the composition of the bottom slag does not change. This study provides theoretical guidance and application support for the selection and optimization of process parameters for water-jet-assisted laser etching of aluminum alloy and further enriches the heat transfer mechanism of multi-field coupling in the process of water-jet-assisted laser machining.


2016 ◽  
Vol 879 ◽  
pp. 274-278 ◽  
Author(s):  
Jun Cao ◽  
Philip Nash

In an earlier study, a 3-D thermomechanical coupled finite element model was built and experimentally validated to investigate the evolution of the thermal residual stresses and distortions in electron beam additive manufactured Ti-6Al-4V build plates. In this study, an investigation using this robust and accurate model was focused on an efficient preheating method, in which the electron beam quickly scanned across the substrate to preheat the build plate prior to the deposition. Various preheat times, beam powers, scan rates, scanning paths and cooling times (between the end of current preheat scan/deposition layer and the beginning of the next preheat scan/deposition layer) were examined, and the maximum distortion along the centerline of the substrate and the maximum longitudinal residual stress along the normal direction on the middle cross-section of the build plate were quantitatively compared. The results show that increasing preheat times and beam powers could effectively reduce both distortion and residual stress for multiple layers/passes components.


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