A Computational Response Surface Study of Three-Dimensional Aluminum Hemming Using Solid-to-Shell Mapping

2006 ◽  
Vol 129 (2) ◽  
pp. 360-368 ◽  
Author(s):  
Guosong Lin ◽  
Jing Li ◽  
S. Jack Hu ◽  
Wayne Cai
Keyword(s):  
Response Surface ◽  
Three Dimensional ◽  
Surface Strain ◽  
Shell Elements ◽  
Surface Study ◽  
Implicit Solver ◽  
Springback Prediction ◽  
Central Composite ◽  
Roll Out

Hemming is a manufacturing process of folding a panel onto itself or another sheet. Quality of hemming is characterized by geometry and formability. This paper presents a response surface study of three-dimensional (3D) curved-surface-curved-edge hemming of an aluminum alloy, AA6111-T4, using finite-element (FE) analysis. Solid elements and explicit FE solver are used for simulations of flanging, pre- and final hemming, and shell elements with implicit solver are deployed for springback prediction. A novel procedure called “solid-to-shell mapping” is developed to bridge the solid elements with the shell elements. Verified to be accurate and efficient, the model is utilized in a central composite design to quantitatively explore the relationships between certain key process variables and the hem dimensional quality and formability. The most significant variables are identified as: (i) prehemming angle on roll-in/roll-out; (ii) nominal surface curvature on sheet springback; and (iii) initial sheet strain and flanging die radius on the maximum hemline surface strain of the produced hem. These results provide insights for process parameter selections in designing and optimizing 3D hems under material formability constraints.

A Computational Response Surface Study of Curved-Surface-Curved-Edge Aluminum Hemming Using Solid-to-Shell Mapping

2006 ◽  
Author(s):  
Guosong Lin ◽  
S. Jack Hu ◽  
Muammer Koc¸ ◽  
Wayne Cai ◽  
Michael L. Wenner
Keyword(s):  
Response Surface ◽  
Surface Strain ◽  
Curved Surface ◽  
Element Analysis ◽  
Shell Elements ◽  
Surface Study ◽  
Implicit Solver ◽  
Springback Prediction ◽  
Roll Out

Hemming is a manufacturing process of folding a panel onto itself or another sheet. Quality of hemming is characterized by geometry and formability. This paper presents a response surface study of 3D curved-surface-curved-edge hemming of an aluminum alloy, AA6111-T4, using finite element analysis. Solid elements and explicit FE solver are used for simulations of flanging, pre- and final hemming, and shell elements with implicit solver are deployed for springback prediction. A novel procedure called “solid to shell mapping” is developed to bridge the solid elements with the shell elements. Verified to be accurate and efficient, the model is utilized in a Central Composite Design to quantitatively explore the relationships between certain key process variables and the hem dimensional quality and formability. The most significant variables are identified as (i) pre-hemming angle on roll-in/roll-out; (ii) nominal surface curvature on sheet springback; (iii) initial sheet strain and flanging die radius on the maximum hemline surface strain of the produced hem. These results provide insights for process parameter selections in designing and optimizing 3D hems under material formability constraints.

Research on Blanching Pretreatment of Quick Frozen Sword Bean (Canavalia gladiate)

2011 ◽  
Vol 140 ◽  
pp. 416-420
Author(s):  
Chen Wei Zhou ◽  
Juan Xu ◽  
Qing Qing Li ◽  
Rui Zhi Wang ◽  
Lu Yang ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Statistical Model ◽  
Response Surface ◽  
Peroxidase Activity ◽  
Primary Determinant ◽  
Central Composite Experimental Design ◽  
Main Index ◽  
Temperature Time ◽  
Central Composite

Quick frozen could preserve the maximum micro-texture and taste quality of vegetables, and blanching pretreatment is primary determinant of quick frozen. In this study, the central composite experimental design and response surface methodology were adopted to derive a statistical model for the effect of blanching pretreatment on the quality of sword bean (Canavalia gladiate), with peroxidase activity as main index. The pretreatment process optimized with response surface methodology was blanching at 96 °C for 1.03 min. Through optimization, a statistical model was established for the relation between blanching temperature, time and peroxidase activity, which would facilitate the prediction of the effects of blanching on the quality of sword bean and could play a guidance role in the blanching pretreatment of many other vegetables.

Hull Plate Bending Springback Prediction Based on Artificial Neural Network

2014 ◽  
Vol 988 ◽  
pp. 309-312
Author(s):  
Shao Juan Su ◽  
Yong Hu ◽  
Cheng Fang Wang ◽  
Bin Liu
Keyword(s):  
Neural Network ◽  
Bp Neural Network ◽  
Three Dimensional ◽  
Plate Bending ◽  
Forming Process ◽  
Cold Bending ◽  
Matlab Programming ◽  
Springback Prediction ◽  
Surface Plate

In the process of three-dimensional curved hull plate forming, springback caused serious influence on the forming accuracy, in order to ensure the forming quality of the asymmetric multiple pressure heads CNC bending machine of ship hull 3D surface plate, to achieve the automatic processing, it is necessary to solve the problem of springback in the hull plate forming process. It is rarely to see the research on the cold bending springback problem of middle-thickness hull plate now. To established nonlinear model of plate parameters and springback amount based on BP neural network, accurately analyzing the prediction of springback, and getting the sptringback prediction model based on the BP neural network in the Matlab programming.

scholarly journals Densification and volumetric change during supersolidus liquid phase sintering of prealloyed brass Cu28Zn powder: Modeling and optimization

2014 ◽  
Vol 46 (1) ◽  
pp. 23-35 ◽  
Author(s):  
A. Mohammadzadeh ◽  
M. Azadbeh ◽  
Sabahi Namini
Keyword(s):  
Response Surface Methodology ◽  
Liquid Phase ◽  
Response Surface ◽  
Three Dimensional ◽  
Liquid Phase Sintering ◽  
Central Composite Rotatable Design ◽  
Volumetric Change ◽  
Short Period ◽  
Central Composite ◽  
Rotatable Design

An investigation has been made to use response surface methodology and central composite rotatable design for modeling and optimizing the effect of sintering variables on densification of prealloyed Cu28Zn brass powder during supersolidus liquid phase sintering. The mathematical equations were derived to predict sintered density, densification parameter, porosity percentage and volumetric change of samples using second order regression analysis. As well as the adequacy of models was evaluated by analysis of variance technique at 95% confidence level. Finally, the influence and interaction of sintering variables, on achieving any desired properties was demonstrated graphically in contour and three dimensional plots. In order to better analyze the samples, microstructure evaluation was carried out. It was concluded that response surface methodology based on central composite rotatable design, is an economical way to obtain arbitrary information with performing the fewest number of experiments in a short period of time.

scholarly journals Hole design quality identification in laser aided additive manufacturing

2016 ◽  
Vol 232 (5) ◽  
pp. 909-917 ◽  
Author(s):  
Il Hyuk Ahn ◽  
Seung Ki Moon ◽  
Guijun Bi
Keyword(s):  
Response Surface Methodology ◽  
Additive Manufacturing ◽  
Response Surface ◽  
Manufacturing Process ◽  
Three Dimensional ◽  
Geometric Error ◽  
Design Quality ◽  
Circular Holes ◽  
High Level

According to the increasing needs of three-dimensional printing technologies to satisfy high-level requirements, customization, and complicity, the quality of three-dimensional printed part becomes an important issue due to the layer-wise nature of additive manufacturing process. The objective of this study is to propose a methodology to identify the quality of three-dimensional printed parts with circular holes in the laser aided additive manufacturing process. We utilize a response surface methodology to represent the relationship between input variables (chord height tolerance and diameter of a hole) and response (geometric error) for evaluating the geometric accuracy of the three-dimensional printed parts with the diameter of holes. From the calculated response surface methodology, we conclude that the proposed methodology can be utilized as a process design guide to guarantee the quality of a part printed from the laser aided additive manufacturing process. The efficiency and limitations of the proposed methodology are verified by conducting a case study.

Three-Dimensional Numerical Simulations of Curved Edge-Curved Surface Hemming of Aluminum Alloy

2004 ◽  
Author(s):  
Guosong Lin ◽  
Muammer Koc¸ ◽  
S. Jack Hu ◽  
Wayne Cai
Keyword(s):  
Aluminum Alloy ◽  
Numerical Simulations ◽  
Three Dimensional ◽  
Element Model ◽  
Curved Surface ◽  
Shell Elements ◽  
Simulation Procedure ◽  
Solid Element ◽  
Complete Procedure

Hemming is a manufacturing process to fold a sheet onto itself or another sheet. The dimensional defects (roll-in/rollout, warp/recoil, distortion due to springback, etc.) of hems critically impact the perceived quality of automotive exteriors. This paper summarizes the procedures and the results of three-dimensional (3D) numerical simulations on curved edge-curved surface hemming of aluminum alloy AA6111-T4PD. A solid-element model is built in ABAQUS using explicit quasi-static finite element (FE) procedure for flanging, pre-hemming and final hemming, and implicit procedure for the corresponding preloading and resulting springback at high simulation cost. Aiming at improving the computational efficiency, various approaches have been taken and tested including using shell elements as alternatives, developing simplified simulation procedure by combining pre- and final hemming in explicit scheme, and further simplification by neglecting intermediate springback analysis. The same conditions are analyzed using shell elements in LS-DYNA, but only final hemming springback is considered. The results of the simplified models are compared with the results of ABAQUS solid-element model with complete procedure. Both accuracy and efficiency of the models are presented and discussed.

Scanning Electron Microscopy in Hybrid Microelectronics

1976 ◽  
Vol 34 ◽  
pp. 456-457
Author(s):  
S. Khadpe ◽  
R. Faryniak
Keyword(s):  
Integrated Circuits ◽  
Thick Film ◽  
Integrated Circuit ◽  
Failure Modes ◽  
Three Dimensional ◽  
Circuit Components ◽  
Hybrid Microcircuit ◽  
Electrical Connections ◽  
Scanning Electron

The Scanning Electron Microscope (SEM) is an important tool in Thick Film Hybrid Microcircuits Manufacturing because of its large depth of focus and three dimensional capability. This paper discusses some of the important areas in which the SEM is used to monitor process control and component failure modes during the various stages of manufacture of a typical hybrid microcircuit.Figure 1 shows a thick film hybrid microcircuit used in a Motorola Paging Receiver. The circuit consists of thick film resistors and conductors screened and fired on a ceramic (aluminum oxide) substrate. Two integrated circuit dice are bonded to the conductors by means of conductive epoxy and electrical connections from each integrated circuit to the substrate are made by ultrasonically bonding 1 mil aluminum wires from the die pads to appropriate conductor pads on the substrate. In addition to the integrated circuits and the resistors, the circuit includes seven chip capacitors soldered onto the substrate. Some of the important considerations involved in the selection and reliability aspects of the hybrid circuit components are: (a) the quality of the substrate; (b) the surface structure of the thick film conductors; (c) the metallization characteristics of the integrated circuit; and (d) the quality of the wire bond interconnections.

Semi-automated methods for 3-D reconstruction of macromolecular complexes

1995 ◽  
Vol 53 ◽  
pp. 42-43
Author(s):  
B. Carragher ◽  
M. Whittaker
Keyword(s):  
Three Dimensional ◽  
Time Saving ◽  
Macromolecular Complexes ◽  
Symmetry Properties ◽  
Dimensional Reconstruction ◽  
Experienced Operator ◽  
Projection Images ◽  
The Individual ◽  
Natural Symmetry

Techniques for three-dimensional reconstruction of macromolecular complexes from electron micrographs have been successfully used for many years. These include methods which take advantage of the natural symmetry properties of the structure (for example helical or icosahedral) as well as those that use single axis or other tilting geometries to reconstruct from a set of projection images. These techniques have traditionally relied on a very experienced operator to manually perform the often numerous and time consuming steps required to obtain the final reconstruction. While the guidance and oversight of an experienced and critical operator will always be an essential component of these techniques, recent advances in computer technology, microprocessor controlled microscopes and the availability of high quality CCD cameras have provided the means to automate many of the individual steps.During the acquisition of data automation provides benefits not only in terms of convenience and time saving but also in circumstances where manual procedures limit the quality of the final reconstruction.

Towards Predicting Relative Belt Edge Endurance With the Finite Element Method

1990 ◽  
Vol 18 (4) ◽  
pp. 216-235 ◽  
Author(s):  
J. De Eskinazi ◽  
K. Ishihara ◽  
H. Volk ◽  
T. C. Warholic
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Three Dimensional ◽  
The Finite Element Method ◽  
Shear Deformations ◽  
Element Analysis ◽  
Vertical Loading ◽  
Predicted Values ◽  
Element Method

Abstract The paper describes the intention of the authors to determine whether it is possible to predict relative belt edge endurance for radial passenger car tires using the finite element method. Three groups of tires with different belt edge configurations were tested on a fleet test in an attempt to validate predictions from the finite element results. A two-dimensional, axisymmetric finite element analysis was first used to determine if the results from such an analysis, with emphasis on the shear deformations between the belts, could be used to predict a relative ranking for belt edge endurance. It is shown that such an analysis can lead to erroneous conclusions. A three-dimensional analysis in which tires are modeled under free rotation and static vertical loading was performed next. This approach resulted in an improvement in the quality of the correlations. The differences in the predicted values of various stress analysis parameters for the three belt edge configurations are studied and their implication on predicting belt edge endurance is discussed.

Sign in / Sign up

Export Citation Format

Share Document