Numerical and Experimental Studies on Hydro-Forming of a Thin Metallic Disc

2022 ◽  
Vol 1048 ◽  
pp. 270-278
Author(s):  
Kanakadandi Gopinath ◽  
Vijayabaskar Narayanamurthy ◽  
Yendluri Venkata Daseswara Rao
Keyword(s):  
Plastic Strain ◽  
Fluid Pressure ◽  
Experimental Studies ◽  
Equivalent Plastic Strain ◽  
Sheet Thickness ◽  
Isotropic Hardening ◽  
Hydraulic Pressure ◽  
Forming Process ◽  
Element Analysis ◽  
Explicit Finite Element

This paper deals with the hydro-forming of a flat thin metallic disc to achieve a forward domed disc which will be subsequently adopted to manufacture a rupture disc. The plastic deformation induced by the hydraulic energy is numerically simulated through an isotropic hardening plasticity model using a non-linear explicit finite element analysis (FEA). The variation in disc’s central deformation, thickness, equivalent plastic stress and equivalent plastic strain with respect to the applied hydraulic pressure are determined from FEA simulations. The hydro-forming setup is then designed and manufactured, and the metallic disc is experimented under hydro-forming process. The reduction in thickness due to stretching of the thin disc is evaluated from experiment and simulation and a close agreement is found. This research attempt helped in finalizing the hydro-forming fluid pressure, the feasibility and the accuracy of practically achieving the desired geometry of the metallic disc. The near-fixidity effects on abrupt variation in sheet thickness and plastic strain are well captured through simulations which are very difficult to be studied through hydro-forming experiments.

Texture-Based Explicit Finite-Element Analysis of Sheet Metal Forming

2005 ◽  
Vol 495-497 ◽  
pp. 1535-1540 ◽  
Author(s):  
Svetlana Ristić ◽  
S. He ◽  
Albert Van Bael ◽  
Paul van Houtte
Keyword(s):  
Finite Element ◽  
Sheet Thickness ◽  
Isotropic Hardening ◽  
Explicit Integration ◽  
Element Analysis ◽  
Integration Algorithm ◽  
Explicit Finite Element ◽  
Finite Element Software ◽  
Fully Implicit ◽  
Explicit Finite Element Analysis

An explicit integration algorithm using a texture-based plastic potential and isotropic hardening has been developed and implemented into a commercial explicit finite-element software program through a user material subroutine (VUMAT in ABAQUS/Explicit). Simulations of cup drawing of an IF-steel are presented and compared to both experimental data and calculation results obtained with a previously developed fully implicit approach (UMAT in ABAQUS/Standard). The explicit formulation has the advantage of being more stable, but local sheet thickness variations cannot be reproduced with the same accuracy.

Finite Element Analysis for the Roll Forming Process of Rib

2018 ◽  
Vol 878 ◽  
pp. 302-307
Author(s):  
Dong Won Jung
Keyword(s):  
Finite Element ◽  
Plastic Strain ◽  
Equivalent Plastic Strain ◽  
Von Mises Stress ◽  
Roll Forming ◽  
Thickness Variation ◽  
Forming Process ◽  
Element Analysis ◽  
High Production Rate ◽  
Roll Forming Process

Roll forming is a continuous profile production process to form sheet metal progressively into the desired shape with closer tolerances. The process offers several advantages such as complex geometrical shapes, high strength, dimensional accuracy, closer tolerances, better quality and consistency, high production rate, improved conformity, and good surface finish. Several parts of automobile body are produced with this process. Nowadays roll forming technology draws more attentions than before in the automotive industry. In this paper, A Finite Element Method applied to study von mises stress, equivalent plastic strain, thickness, plastic strain, longitudinal strain and spring back of the metal sheet with ribs formed by roll forming process. The thickness variation was almost -6.144%.

Analysis of Plastic Strain between Substrate and Micro-Cantilever under Different Deformation Characteristics

2013 ◽  
Vol 477-478 ◽  
pp. 21-24
Author(s):  
Hui Kai Gao ◽  
Jian Meng Huang
Keyword(s):  
Plastic Strain ◽  
Rough Surface ◽  
Three Dimensional ◽  
Equivalent Plastic Strain ◽  
Adhesive Contact ◽  
Contact Model ◽  
Deformation Characteristics ◽  
Element Analysis ◽  
Flat Substrate ◽  
Micro Cantilever

The contact between substrate and micro-cantilever simplified as an ideal flat substrate contact with a micro-cantilever rough surface. A three-dimensional adhesive contact model was established on isotropic rough surfaces exhibiting fractal behavior, and the equivalent plastic strain was discussed using the finite element analysis. The maximum equivalent plastic strain and its depth were presented with the different paths of rough solid when loading. The result show that the equivalent plastic strain versus different depth which at different locations showed different laws, in the top area of the asperities versus different depth, the maximum equivalent plastic strain occurs in the subsurface range about 0.5μm from the surface or on the surface. In addition, with different deformation characteristics, the degree of the equivalent plastic strain was different.. The contact model between micro-cantilever rough surface and flat substrate will lay a foundation to further research on the substance of the process of friction and wear.

Numerical Investigations on Cutting of Dual-Phase Sheet Steel with an Emphasis on Material Damage at the Cut Edge

2013 ◽  
Vol 769 ◽  
pp. 101-108 ◽  
Author(s):  
Ilya Peshekhodov ◽  
Matthias Schneider
Keyword(s):  
Sheet Steel ◽  
Equivalent Plastic Strain ◽  
Stress Triaxiality ◽  
Future Research ◽  
Dual Phase ◽  
Element Analysis ◽  
Punch Force ◽  
Explicit Finite Element ◽  
Cut Edge ◽  
Edge Geometry

With the help of an explicit finite element analysis, cutting of cold-rolled dual-phase steels for various tool clearances was studied. In the first part of the study, the influence of the element size in the shear zone of the sheet on the predicted cut edge geometry and punch force was assessed and the optimal simulation parameters were identified. In the second part, the fracture description was put into focus of the investigation. It is shown that the used mathematical description of the equivalent plastic strain at fracture as a function of the stress triaxiality does not yield accurate results for FEA-based prediction of the cut edge geometry. A need in a more accurate fracture characterisation and, possibly, a more advanced fracture description of dual-phase sheet steels and the directions of the future research are identified.

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.

An Experimental and Numerical Study on Forming Force, Fracture Behavior, and Strain States in Two Point Incremental Forming Process

2016 ◽  
Vol 725 ◽  
pp. 586-591
Author(s):  
Chen Hao Wang ◽  
William J.T. Daniel ◽  
Hai Bo Lu ◽  
Sheng Liu ◽  
Paul Anthony Meehan
Keyword(s):  
Plastic Strain ◽  
Fracture Behavior ◽  
Numerical Study ◽  
Equivalent Plastic Strain ◽  
Fem Simulation ◽  
Forming Force ◽  
Forming Process ◽  
Approaches To Study ◽  
Tool Diameter ◽  
Numerical Approaches

Two-point incremental sheet forming process (TPIF) is an emerging and promising manufacturing process for the production of complex geometries or customized functional sheet components. In this study, the single-pass TPIF process is investigated using experimental and numerical approaches to study the forming force evolution, fracture behavior and strain states with a varied wall angle hemisphere shape. It can be concluded that both the peak force and fracture depth increases with tool diameter and incremental depth in TPIF process. It seems the deformation mechanism or the failure mechanism is strongly dependent on particular forming conditions based on a failure parts morphology observation. FEM simulation results indicated that the major plastic strain is positive while the minor plastic strain is negative in the TPIF process on a hemiphere shape. it can be concluded that the strain increment and total equivalent plastic strain is affected by both tool diameter and incremental depth.

Revisiting the Deshpande-Fleck Foam Model

2019 ◽  
Vol 803 ◽  
pp. 134-139
Author(s):  
Chang Feng Zhu ◽  
Zhi Jun Zheng ◽  
Shi Long Wang ◽  
Kai Zhao ◽  
Ji Lin Yu
Keyword(s):  
Finite Element ◽  
Plastic Strain ◽  
Equivalent Plastic Strain ◽  
Element Model ◽  
The Self ◽  
Isotropic Hardening ◽  
Hardening Model ◽  
Foam Model ◽  
A Cell ◽  
Self Similar

The self-similar isotropic hardening model developed by Deshpande and Fleck has been widely used. An important issue in this model is to determine the value of ellipticity. The ellipticity was treated as a constant in the subsequent yield, but different values were suggested in the literature. In this paper a cell-based finite element model based on the 3D Voronoi technique is used to verify the Deshpande-Fleck foam model. It is found that the ellipticity determined from uniaxial and hydrostatic compressions varies with the equivalent plastic strain.

Analysis of the Anti-Bird Impact Performance of Typical Beam-Edge Structure Based on ANSYS/LS-DYNA

2008 ◽  
Vol 33-37 ◽  
pp. 395-400 ◽  
Author(s):  
Yong Kang Zhang ◽  
Yu Long Li
Keyword(s):  
Plastic Strain ◽  
Failure Process ◽  
Equivalent Plastic Strain ◽  
Leading Edge ◽  
Analysis Model ◽  
Element Analysis ◽  
Edge Structure ◽  
Deformation And Failure ◽  
Bird Impact ◽  
Beam Edge

The 3-D finite element analysis model of beam-edge structure with spaced multiple layers under bird impact is established. Numerical simulations are implemented by using the non-linear contact-impact code ANSYS/LS-DYNA when the birds collide at three locations of the structure respectively. The failure process of the structure and the equivalent plastic strain at supports are obtained. The residual strength of the structure after impact is predicted. The results show that the front spars are penetrated or cracked after the leading edge is perforated. The equivalent plastic strain at the support is much higher when the bird impacts the structure at the central location. Both the structure deformation and failure mode from the simulation are consistent with the results of full scale test, which proves the validity of the method proposed in this paper.

Effects of Local Peak Stress Distribution on the Ratchet Limit

2002 ◽  
Author(s):  
Nobuyoshi Yanagida ◽  
Masaaki Tanaka ◽  
Norimichi Yamashita ◽  
Yukinori Yamamoto
Keyword(s):  
Finite Element ◽  
Stress Distribution ◽  
Plastic Strain ◽  
Equivalent Stress ◽  
Equivalent Plastic Strain ◽  
Peak Stress ◽  
Element Analysis ◽  
Stress Evaluation ◽  
Elastic Plastic ◽  
Plastic Analysis

Alternative stress evaluation criteria suitable for Finite Element Analysis (FEA) proposed by Okamoto et al. [1],[2] have been studied by the Committee on Three Dimensional Finite Element Stress Evaluation (C-TDF) in Japan. Thermal stress ratchet criteria in plastic FEA are now under consideration. Two criteria are proposed: (1) Evaluating variations in plastic strain increments, and (2) Evaluating the width of the area in which Mises equivalent stress exceeds 3Sm. To verify of these criteria, we selected notched cylindrical vessel models as prime elements. To evaluate the effect of the local peak stress distribution on these criteria, cylindrical vessels with a semicircular notch on the outer surface were selected for this analysis. We used two notch configurations for our analysis, and the stress concentration factor for the notches was set to 1.5 and 2.0. We conducted elastic-plastic analysis to evaluate the ratchet limit. Sustained pressure and alternating enforced longitudinal displacements which causes secondary stress were used as parameters for the elastic-plastic analysis. We found that when no ratchet was observed, the equivalent plastic strain increments decreased and the area in which Mises equivalent stress exceeds 3Sm are below the certain range.

Sign in / Sign up

Export Citation Format

Share Document