Prediction of deep drawing ratio by using finite element method

Dissertant

Abbas, Khalil Ibrahim

University

University of Technology

Faculty

-

Department

Department of Production Engineering and Metallurgy

University Country

Iraq

Degree

Master

Degree Date

2006

English Abstract

This research aims to predict the limiting drawing ratio in deep drawing process.

Where, the numerical procedure was proposed for the design of deep drawing process using (FEM).

A simplified 2D-axisymmetric model of cylindrical cup was performed on a commercial low carbon (1800 - AISI) steel sheet material (to = 0.5 mm) thickness, punch diameter (Dp = 43 mm) and different blank diameters (Db = 78, 80, 82, 86, 90 mm) as a main of determining the limiting drawing ratio LDR.

The results from a study of the numerical prediction of limiting draw ratio (LDR) are presented.

A series of twelve different tooling geometries were considered for a cylindrical cup drawing process, with the differences being variations in the punch profile radii P (4, 6) mm, die profile radii D (2, 4, 6, 8, 10, 12) mm and friction coefficient n (0.05, 0.1, 0.15).

After that the variables are applied [blank holder force BHF (1.25, 2.5, 5, 10) KN, drawing speed V (60, 120, 240, 480, 600, 1000) mm / min, punch profile radius P (2, 4, 6, 8, 10, 12) mm] to study their the effect on the chosen LDR.

And to show the effect of draw bead profile on LDR, five models of high draw bead H (0.5, 1, 2, 3, 4) mm are used.

Tn addition, five models were to study the effect of mesh refinement on the prediction of drawing force and time solution.

A validation study in which numerical predictions were compared with experiments was performed on five different tooling geometries [two models of conventional deep drawing P (4, 6) mm D8 mm and three models with draw bead profiles P4 D8 H (0.5, 1, 2) mm].

These studies demonstrate that the numerical model accurately captured the forming process.

The drawing forces, thickness, and strain distributions for the products are found to be in reasonable agreement with the experiments.

Thus, are can predict the failure or successful cups and predicts the LDR By evaluation of the thickness and strain distributions of the cup wall.

The distance between bottom blank surface and the die surface at flange region represents an indicator j to occurrence of wrinkling (theoretical and experimental).

The LDR predictions were found to be sensitive to die radii effects but were less sensitive to the effect of changes in punch radii.

The speed was found to have a weak influence on the predictions of LDR ; This may refer to using similar coulomb friction coefficient at all speeds.

Also these studies demonstrate that when are represents different coefficients of friction at main contact regions (B.H / blank, blank / die, punch / blank) in FE model, they give results that agree more with the experiments.

The simulation of the model of draw bead profile by FEM predicted an improvement in thickness and strain distribution of LDR with H = 0.5 mm.

The experimental work proved the validity of this prediction.

The accuracy of elements distribution and the number of elements affect the prediction of drawing force value and time solution.

Main Subjects

Engineering & Technology Sciences (Multidisciplinary)

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305995