scholarly journals Investigating Fracture Failure in Origami-based Sheet Metal Bending

2021 ◽  
Author(s):  
Muhammad Ali Ablat ◽  
Ala’aldin Alafaghani ◽  
Jian-Qiao Sun ◽  
Chetan Nikhare ◽  
Ala Qattawi
Keyword(s):  
Sheet Metal ◽  
Sheet Thickness ◽  
Fracture Criteria ◽  
Element Analysis ◽  
Ductile Fracture Criteria ◽  
Fracture Failure ◽  
Research Goal ◽  
Ratio Limit ◽  
Sheet Metal Bending ◽  
Free Bending

Abstract Origami-based sheet metal (OSM) bending is a promising new die-free folding technique for sheet metal. OSM bending principle is based on deforming the material along a pre-defined fold line, which is determined using material discontinuity (MD) produced by laser or waterjet cutting. The objective of this work is to study and evaluate the fracture in OSM bending under the influence of various MD types, kerf-to-thickness (k/t) ratios, and sheet thicknesses. The research goal is to provide information on selecting an optimized k/t ratio and type of MD that allows for fracture-free bending. Four different ductile fracture criteria (DFC) are used and calibrated from experimental data to forecast fracture. The DFC calibration is used to produce a set of critical damage values (CDV) for assessing the possibility of fracture in the OSM bending. In addition, the study provides fracture evaluation using finite element analysis (FEA) integrated with experimental cases for a broader range of OSM bending parameters and MDs. The results demonstrated that an MD with a higher k/t ratio is less likely to fracture during the OSM bending, whereas a higher sheet thickness increases the possibility of fracture. Furthermore, the study identifies the k/t ratio limit that ensures successful bending without fracture and categorizes MD types into two groups based on fracture likelihood. The fracture in the first group is dependent on the limiting k/t ratio, whereas the possibility of fracture in the second group is independent of the k/t ratio due to its topology.

Finite Element Analysis of the Hydro-Mechanical Punching Process

2006 ◽  
Vol 505-507 ◽  
pp. 871-876
Author(s):  
Jong Hun Yoon ◽  
Hoon Huh ◽  
Yong Sin Lee ◽  
Seung Soo Kim ◽  
E.J. Kim ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Ductile Fracture ◽  
Sheet Material ◽  
Middle Surface ◽  
Initial Crack ◽  
Fracture Criteria ◽  
Element Analysis ◽  
Final Fracture ◽  
Ductile Fracture Criteria ◽  
Punching Process

This paper investigates the characteristics of a hydro-mechanical punching process. The hydro-mechanical punching process is divided into two stages: the first stage is the mechanical half piercing in which an upper punch goes down before the initial crack is occurred; the second stage is the hydro punching in which a lower punch goes up until the final fracture is occurred. Ductile fracture criteria such as the Cockcroft et al., Brozzo et al. and Oyane et al. are adopted to predict the fracture of a sheet material. The index value of ductile fracture criteria is calculated with a user material subroutine, VUMAT in the ABAQUS Explicit. The hydrostatic pressure retards the initiation of a crack in the upper region of the blank and induces another crack in the lower region of the blank during the punching process. The final fracture zone is placed at the middle surface of the blank to the thickness direction. The result demonstrates that the hydro-mechanical punching process makes a finer shearing surface than the conventional one as hydrostatic pressure increases.

Research on the Finite Element Simulation of the Laser Shock Forming of TC4 Titanium Alloy

2016 ◽  
Vol 693 ◽  
pp. 1121-1128 ◽  
Author(s):  
Guo He Li ◽  
David Mbukwa ◽  
Wei Zhao
Keyword(s):  
Finite Element ◽  
Sheet Metal ◽  
Laser Energy ◽  
Sheet Thickness ◽  
High Amplitude ◽  
Laser Spot ◽  
Laser Shock ◽  
Forming Process ◽  
Element Analysis ◽  
Laser Shock Forming

laser shock forming, which combines the metal forming and material modification, is a non-mode, flexible forming new technology using laser-induced force effect of high amplitude shock waves to obtain the plastic deformation of sheet metal. in this paper, the simulation of laser shock forming process of tc4 sheet metal was carried out through the commercial finite element analysis software abaqus. the influence of the sheet thickness, laser energy, constraints aperture and laser spot spacing on the sheet metal deformation are investigated. the results show that: with the increase of sheet thickness, the deformation range of sheet decreases, and the amplitude of deformation decreases firstly and then increases. the deformation increases linearly with the increase of laser energy. the larger boundary constraint aperture leads to the larger deformation of sheet metal. there are no obvious influence on the forming accuracy when an opposite laser spot spacing is adopted. therefore, under the condition of meeting the accuracy requirement, for improving the efficiency, adopting a certain laser spot spacing to finish the forming should be considered.

scholarly journals Direct Optimization of an Automotive Sheet Metal Part Using ANSYS

2020 ◽  
Vol 5 (3) ◽  
pp. 134-142
Author(s):  
Usman Khalid ◽  
Othman Mohammad Ahmed Mustafa ◽  
Muhammad Ali Naeem ◽  
Mohammad Yousef Mohammad Alkhateeb ◽  
Basil Marwan Abed Eljaber Awad
Keyword(s):  
Sheet Metal ◽  
Sheet Thickness ◽  
Cost Effective ◽  
Sheet Metal Part ◽  
Metal Part ◽  
Direct Optimization ◽  
Element Analysis ◽  
Automotive Sheet ◽  
Automotive Parts ◽  
The Cost

Optimization of automotive parts nowadays is mainly used to design lightweight and cost-effective vehicle parts in order to improve the cost and efficiency. In this research, a sheet metal part was taken into consideration and optimized using direct optimization module in ANSYS to evaluate the process. An initial Finite Element Analysis (FEA) was done on the sheet metal part by adding forces and constraints in order to initiate direct optimization. The purpose of the optimization is to minimize the mass of the sheet metal part and maintaining a certain Factor of Safety (FOS) by automatically modifying the sheet thickness and the dimension of the side holes. As a result, the best candidate point with 23% mass reduction was found which complied with FOS value was selected for optimal geometry.

Application of Incremental Forming in Sheet Metal Bending Process

2014 ◽  
Vol 900 ◽  
pp. 561-564 ◽  
Author(s):  
Xiao Bing Dang ◽  
Kai He ◽  
Shu Guo Wei ◽  
Jiu Hua Li ◽  
Ru Xu Du
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Motion Control ◽  
Sheet Metal ◽  
Incremental Forming ◽  
Single Point ◽  
Element Analysis ◽  
Motion Control Card ◽  
Bending Process ◽  
Sheet Metal Bending

Based on the thought of incremental forming, a new kind of sheet metal bending process has been described and investigated in this article. The software of the control system for the specific machine is developed combining motion control card and servo motors. Both single point and multi-points bending are taken into consideration from experimental and finite element analysis. Curved sheet and hyperbolic sheet metal are examined through experiments to extend the application for more smoothed and complicated curved sheet metal. The effectiveness of the process to deal with complex curved sheet metal is shown by all the experiments.

Fracture Prediction in Sheet Metal Stamping Based on a Modified Ductile Fracture Criterion

2015 ◽  
Vol 639 ◽  
pp. 543-550
Author(s):  
Rong Zeng ◽  
Liang Huang ◽  
Jian Jun Li
Keyword(s):  
Ductile Fracture ◽  
Sheet Metal ◽  
Fracture Criterion ◽  
Fracture Prediction ◽  
Uniaxial Tensile ◽  
Ductile Fracture Criterion ◽  
Fracture Criteria ◽  
Sheet Metal Stamping ◽  
Ductile Fracture Criteria ◽  
Metal Stamping

Sheet metal stamping is an important manufacturing process because of its high production rate and low cost, so the fracture prediction of stamping parts has become important issues. Recent experimental studies have shown that the quality of stamping parts can be increased by using ductile fracture criteria. This paper proposed a modified ductile fracture criterion based on the macroscopic and microscopic continuum damage mechanics (CDM). Three-dimensional (3D) explicit finite element analysis (FEA) are performed to predict the fracture behaviors of sheet metal stamping process. An approach to determine the material constants of modified ductile fracture criterion is presented with the help of uniaxial tensile tests and compressive tests. The results show that the modified ductile fracture criterion enables precise cup depth and fracture location of sheet metal stamping under nonlinear paths. Compared with typical ductile fracture criteria, the results predicted with modified ductile fracture criterion correlate the best with the experimental data.

Prediction of Ductile Fracture in Cold Forging of Aluminum Alloy

1999 ◽  
Vol 121 (3) ◽  
pp. 336-344 ◽  
Author(s):  
Hong-Seok Kim ◽  
Yong-Taek Im ◽  
Manfred Geiger
Keyword(s):  
Ductile Fracture ◽  
Initiation Site ◽  
Cold Forging ◽  
Fracture Criteria ◽  
Element Analysis ◽  
Surface Cracking ◽  
Numerical Investigations ◽  
Ductile Fracture Criteria ◽  
Circumferential Tensile Stress ◽  
Reasonable Prediction

In this paper, the limitation and applicability of the ductile fracture criteria based on a work hypothesis and Cockcroft and Latham were investigated. For this purpose, experimental and numerical investigations for simple upsetting were conducted for aluminum alloys Al1100-O, Al2024-T3, Al6061-T4, and Al7075-T4. As a result, the fracture mode of each alloy was observed. The study was extended for pin-shape cold forging of Al1100-O and Al6061-T4 to compare the likeliness of fracturing according to two criteria. Based on experimental data of simple upsetting, the damage factors for the same two criteria were calculated by adopting rigid-viscoplastic finite element analysis. With this approach, the prediction of surface cracking was attempted by comparing the calculated limiting damage factors between simple upsetting and pin-shape forging. It was observed in simple upsetting that Cockcroft and Latham’s criterion gave a more reasonable prediction for crack initiation site than work hypothesis, but the limiting damage factors differ depending on the process. In spite of the differences, however, Cockcroft and Latham’s criterion might be useful in designing upsetting-like cold forging processes in which the influence of the induced circumferential tensile stress on failure is dominant.

Three-Dimensional Finite Element Analysis of Sheet-Metal Bending With Complex Die Geometry

1997 ◽  
Vol 119 (3) ◽  
pp. 324-331 ◽  
Author(s):  
I-Nan Chou ◽  
Chinghua Hung
Keyword(s):  
Finite Element ◽  
Critical Point ◽  
Sheet Metal ◽  
Tensile Strain ◽  
Three Dimensional ◽  
Element Analysis ◽  
Die Geometry ◽  
The Coefficient Of Friction ◽  
Sheet Metal Bending ◽  
Three Dimensional Finite Element

The purpose of this research was to find manufacturing processing conditions that would prevent the occurrence of fractures in a sheet-metal bending product. The finite element code ABAQUS was used to analyze the tensile strain at the particular point where fractures frequently occur. First an optimal combination of factors was sought using the method of controlling parameters. The analysis showed that the three factors, r2, r4, and the coefficient of friction, which are typical controlling factors, cannot be used to reduce the tensile strain at the critical point efficiently. A preform design was then applied to solve the problem of fracturing. By using a two-step bending operation, we successfully moved the highest tensile strain away from the critical point and also reduced the magnitude of this strain.

Sign in / Sign up

Export Citation Format

Share Document