A Multi-scale Simulation of Micro-forming Process with RKEM

2004 ◽  
Author(s):  
Wing Kam Liu
Keyword(s):  
Micro Forming ◽  
Forming Process ◽  
Multi Scale

Dieless Water Jet Incremental Micro-Forming

2018 ◽  
Author(s):  
Yi Shi ◽  
Jian Cao ◽  
Kornel F. Ehmann
Keyword(s):  
Process Parameters ◽  
Thin Shell ◽  
High Speed ◽  
Single Point ◽  
Sheet Thickness ◽  
Water Jet ◽  
Micro Forming ◽  
Forming Process ◽  
Thin Foils ◽  
High Pressure Water Jet

Compared to the conventional single-point incremental forming (SPIF) processes, water jet incremental micro-forming (WJIMF) utilizes a high-speed and high-pressure water jet as a tool instead of a rigid round-tipped tool to fabricate thin shell micro objects. Thin foils were incrementally formed with micro-scale water jets on a specially designed testbed. In this paper, the effects on the water jet incremental micro-forming process with respect to several key process parameters, including water jet pressure, relative water jet diameter, sheet thickness, and feed rate, were experimentally studied using stainless steel foils. Experimental results indicate that feature geometry, especially depth, can be controlled by adjusting the processes parameters. The presented results and conclusions provide a foundation for future modeling work and the selection of process parameters to achieve high quality thin shell micro products.

scholarly journals Macro-meso scale simulations of 3D woven composite reinforcements during the forming process

2021 ◽  
Author(s):  
Jie Wang ◽  
Peng Wang ◽  
Nahiène Hamila ◽  
Philippe Boisse
Keyword(s):  
Computational Cost ◽  
Constitutive Law ◽  
Forming Process ◽  
Multi Scale ◽  
Rtm Process ◽  
Macroscopic Simulation ◽  
Deformations And Orientations ◽  
High Computational Cost ◽  
Meso Scale ◽  
Composite Reinforcements

During the forming stage in the RTM process, deformations and orientations of yarns at the mesoscopic scale are essential to evaluate mechanical behaviors of final composite products and calculate the permeability of the reinforcement. However, due to the high computational cost, it is very difficult to carry out a mesoscopic draping simulation for the entire reinforcement. In this paper, a macro-meso scale simulation of composite reinforcements is presented in order to predict mesoscopic deformations of the fabric in a reasonable calculation time. The proposed multi-scale method allows linking the macroscopic simulation of the reinforcement with the mesoscopic modelling of the RVE through a macromeso embedded analysis. On the base of macroscopic simulations using a hyperelastic constitutive law of the reinforcement, an embedded mesoscopic geometry is first deduced from the macroscopic simulation of the draping. To overcome the inconvenience of the macro-meso embedded solution which leads to unreal excessive yarn extensions, local mesoscopic simulations based on the embedded analysis are carried out on a single RVE by defining specific boundary conditions. Finally, the multi-scale forming simulations are investigated in comparison with the experimental results, illustrating the efficiency of the proposed approach, in terms of accuracy and CPU time.

Evaluation of Local Material Flow during Complex Deformation Conditions on the Basis of Multi Scale Analysis

2016 ◽  
Vol 682 ◽  
pp. 350-355
Author(s):  
Joanna Szyndler ◽  
Lukasz Madej
Keyword(s):  
Material Flow ◽  
Incremental Forming ◽  
Material Behavior ◽  
Scale Analysis ◽  
Forming Process ◽  
Complex Deformation ◽  
Multi Scale ◽  
Local Material ◽  
Scale Levels ◽  
Digital Material

Development of the multiscale numerical model of innovative incremental forming process, dedicated for manufacturing complex components for the aerospace industry is the main aim of the work. Description of the incremental forming concept based on division of large die into a series of small anvils subsequently pressed into the material is presented within the paper. Particular attention is put on material behavior at both, macro and micro scale levels, respectively. A Finite Element Method (FEM) supported by Digital Material Representation (DMR) concept was used during the investigation. Results in the form of strain distributions and shapes of grains obtained from different sample areas after incremental forming process are presented within the paper.

Effect of Workpiece Thickness and Surface Texturing on the Micro Cupping Tests

2014 ◽  
Vol 626 ◽  
pp. 420-425
Author(s):  
Heng Sheng Lin ◽  
Ying Chieh Lin ◽  
Ming Ru Lee
Keyword(s):  
Stainless Steel ◽  
Body Force ◽  
Surface Texturing ◽  
Surface Force ◽  
Micro Forming ◽  
Forming Process ◽  
Sand Blasting

The miniaturization of products has driven the demand for better realization in the micro forming process. Micro sheetmetal forming becomes more susceptible to friction attributed to the decrease in the weighting of body force and the increase in surface force, as the size of workpiece decreases. In this work, micro cupping tests were utilized to test the influence of workpiece thickness and surface texturing both on stainless steel and copper sheets under an oil-lubricated condition. Three thickness gauges of workpiece, 0.05, 0.1 and 0.2 mm, were selected in order to represent the micro, meso and macro forming conditions, respectively. Longitudinal and isotropic lay conditions were obtained through imprinting the textured rolls produced by grinding and sand blasting methods. The result of the micro cupping tests show that the cup heights are comparable for both longitudinal and isotropic lays in forming the sheets of 0.1 and 0.2 mm thickness. However, isotropic lay has a greater cup height than that of longitudinal lay in forming the 0.05 mm sheets. This indicates that surface texturing becomes influential in the formability of micro sheetmetal forming.

Micro Pattern Forming of Spiral Grooves in a Fluid Dynamic Bearing Using Desktop Forming System

2012 ◽  
Vol 538-541 ◽  
pp. 1203-1207 ◽  
Author(s):  
Jung Han Song ◽  
Jeanho Park ◽  
Jong Sup Lee ◽  
Seo Gou Choi ◽  
Hye Jin Lee ◽  
...  
Keyword(s):  
Fluid Dynamic ◽  
Dynamic Pressure ◽  
Disk Drive ◽  
Spiral Groove ◽  
Micro Forming ◽  
Forming Process ◽  
Micro Pattern ◽  
Fluid Dynamic Bearing ◽  
Pattern Forming ◽  
Groove Pattern

This research explores the micro-forming process of spiral groove pattern on Fluid Dynamic Bearing(FDB), which is utilized in precision driving part of the hard disk drive(HDD), using micro desktop forming system. While EDM and ECM process has been widely used to engrave the precision pattern which generates dynamic pressure on FDBs, micro forming process is newly proposed in this study to increase the productivity and to reduce the product costs. At first, desktop forming system is designed for spiral groove pattern forming. FE simulations are followed in order to evaluate the feasibility of micro-forming. The simulation results show that forming loads of 1,500Kgf is required to fabricate micro patterns with the depth of 15 μm. Finally the formability test is carried out with various forming loads. Deformed shapes and forming loads obtained from the test are compared with those from the analysis. The results fully demonstrate that micro pattern forming techniques are available to fabricate micro spiral groove patterns in FDB.

Estimation of Micro-Formability and FEM Simulation of Micro-Forming Process of a Zr-Based Bulk Metallic Glass

2007 ◽  
Vol 539-543 ◽  
pp. 2129-2134
Author(s):  
Young Sang Na ◽  
S.G. Kang ◽  
K.Y. Park ◽  
Jong Hoon Lee
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Fem Simulation ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Micro Forming ◽  
Forming Process ◽  
Rf Values ◽  
Simulation Results

Micro-forming is considered to be a suited technology to manufacture very small metallic parts (several μm~mm). Zr-based bulk metallic glass, Zr62Cu17Ni13Al8, has been expected to be a promising metallic material for micro-forming process due to their isotropy, low flow stress in a wide supercooled liquid region and good stability of amorphous matrix. Therefore, one can expect that micro-forming of Zr62Cu17Ni13Al8 might be feasible at a relatively low stress in the supercooled liquid state without any crystallization during hot deformation. In this study, micro-formability of Zr62Cu17Ni13Al8 bulk metallic glass was investigated for micro-forging of U-shape pattern. Microformability was estimated by comparing Rf values (=Af/Ag), where Ag is corss-sectional area of U groove, and Af the filled area by material. Micro-forging process was also simulated and analyzed by applying the finite element method. The micro-formability of Zr62Cu17Ni13Al8 was increased with increasing load and time in the temperature range of the supercooled liquid state. In spite of the similar trend in the variations of Rf values, FEM simulation results showed much higher Rf values than the experimental Rf values. This disagreement was analyzed based on the stress overshoot phenomena of bulk metallic glasses in the supercooled liquid region. FEM simulation of the microstamping process was applicable for the optimization of micro-forming process by carefully interpreting the simulation results.

scholarly journals TENDENCIES IN FORMING SHEET METAL PARTS USING INCREMENTAL FORMING ADVANCED TECHNOLOGIES

2019 ◽  
Vol 25 (3) ◽  
Author(s):  
CATALINA CIOFU ◽  
BOGDAN CHIRITA ◽  
ROXANA LUPU ◽  
COSMIN GRIGORAS ◽  
CRINA RADU ◽  
...  
Keyword(s):  
Sheet Metal ◽  
Incremental Forming ◽  
Stretch Forming ◽  
Micro Forming ◽  
Forming Process ◽  
Metal Parts ◽  
Sheet Metal Parts ◽  
Advanced Technologies ◽  
Metal Materials ◽  
Forming Methods

Stretch forming of sheet metal materials is a highly required process in aerospace industry for manufacturing skin parts. Automation of some processes such as cutting, punching, forming, shearing and nesting in conventional manufacturing tends to combine these forming methods. Some researches are made on the formability of sheet metal materials obtained in incremental forming process with stretch forming and water jet incremental micro-forming with supporting dies. This paper is an attempt to review the newly researches made on optimization of manufacturing metal skin parts to achieve geometrical accuracy.

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