UNIVERSITI PUTRA MALAYSIA

NUMERICAL ANALYSIS OF SHOCK WAVE PROPAGATION AND AL5083 SHEET BULGING IN EXPLOSIVE HYDRO FORMING PROCESS

SAEED JABALAMELIAN

FK 2012 124

© COPYRIG

HT UPM

NUMERICAL ANALYSIS OF SHOCK WAVE PROPAGATION AND AL5083 SHEET BULGING IN EXPLOSIVE HYDRO FORMING PROCESS

By

SAEED JABALAMELIAN

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia, in Fulfillment of the Requirement for the Degree of Master Science

January 2012

© COPYRIG

HT UPM

II

DEDICATION

To my beloved parents, that I owe them my entire life

To my supervisor Dr. Aidy Ali who taught me how to be a good researcher

To my compassionate wife, Saeedeh, that without her support I will not be able to complete this dissertation.

© COPYRIG

HT UPM

III

Abstract of thesis presented to the Senate of Universiti Putra Malaysia in fulfillment of the requirement for the degree of Master of Science

NUMERICAL ANALYSIS OF SHOCK WAVE PROPAGATION AND AL5083 SHEET BULGING IN EXPLOSIVE HYDRO FORMING PROCESS

By

SAEED JABALAMELIAN

January 2012

Chairman : Associate Professor Aidy Ali, PhD

Faculty : Engineering

The present work simulated the explosive forming of a torisperical dished head from

the Al-5083 aluminum alloy against a male die. The simulation was used to

investigate the strain distribution across the final product as well as to capture the

complex nature behind this High Energy Rate Forming (HERF) technique. The study

was carried out in the framework of LS-DYNA code, based on the Arbitrary

Lagrangian Eulerian (ALE) Multi-Material formulation, which provided a finite

element mesh that moved independently from the material flow and allowed each

element to contain a mixture of two or more different materials. The underwater

explosion phenomenon including the shock wave propagation and the state of

detonation products was perfectly simulated using the Jones-Wilkins-Lee (JWL) and

Gruneisen equations of state for explosive and water, respectively. The results were

validated based on the Cole’s experimental and analytical works on underwater

explosion of relatively small charge, which showed the average error of 6.4%. The

simulation outcomes showed that the primary shock could be modified by

accelerating the specimen up to 100 m/s and reflecting back toward the water, which

could lead to cavitations. The formation of the cavitations and their effects on the

© COPYRIG

HT UPM

IV

deformation of the specimen were investigated numerically; same as the other

aspects of the desired process. Since many of these phenomena were too difficult to

be investigated experimentally, a comprehensive understanding of the Explosive

Hydro Forming (EHF) process was achieved through a numerical simulation in this

study.

The behavior of the specimen under explosive loading was predicted according to the

Johnson-Cook (JC), Modified Zerilling-Armstrong (MZA) and Plastic-Kinematic

(PK) constitutive equations, which were used to investigate the strain distribution

across the final product. Moreover, three techniques were examined numerically

involving increasing the ratio between the thickness and diameter of sheet plate,

using the sheet holder and grooving the edge of the workpiece to reduce the

wrinkling at the edge of the workpiece.

© COPYRIG

HT UPM

V

Abstrak tesis yang dikemukakan kepada Senat Universiti Putra Malaysia sebagai memenuhi keperluan untuk ijazah Master Sains

ANALISA BERANGKA TERHADAP PENYEBARAN GELOMBANG KEJUTAN DAN PROSES BENJOLAN KEPINGAN AL5083 DALAM

PROSES PEMBENTUKAN LETUPAN HIDRO

Oleh

SAEED JABALAMELIAN

Januari 2012

Pengerusi : Profesor Madya Aidy Ali, PhD

Fakulti : Kejuruteraan

Kajian ini melibatkan simulasi pembentukan menggunakan peledak ke atas penutup

torisferikal yang diperbuat daripada aloi aluminium AL-5083 menggunakan acuan.

Simulasi ini digunakan untuk mengkaji pengagihan tekanan produk akhir serta untuk

memahami teknik Pembentukan Kadar Tenaga Tinggi (HERF) yang kompleks.

Kajian ini dijalankan dengan menggunakan rangka kerja berkod LS-DYNA,

berdasarkan Formulasi bahan rencam “Arbitrary Lagrangian Eulerian (ALE)” yang

menyediakan asas unsur terhad yang bergerak secara bebas daripada arus bahan dan

membenarkan setiap elemen untuk mempunyai campuran dua atau lebih bahan yang

berlainan. Fenomena ledakan dalam air seperti pengagihan gelombang kejut dan

ledakan produk telah disimulasi secara tepat menggunakan persamaan-persamaan

Jones-Wilkins-Lee (JWL) dan Gruneisen, masing-masing untuk ledakan dalam air.

Hasil kajian tersebut telah disahkan oleh ujikaji dan hasil analisa Cole ke atas

ledakan bawah air berskala kecil yang menunjukkan ralat maksimum 6.4 %. Hasil-

hasil simulasi menunjukkan gelombang kejutan pertama boleh diubahsuai dengan

meningkatkan kelajuan spesimen sebanyak 100 m/s dan ditampan oleh air, di mana

© COPYRIG

HT UPM

VI

peronggaan akan berlaku. Pembentukan peronggaan dan kesan-kesannya ke atas

herotan spesimen dikaji secara berangka, sama seperti aspek lain untuk proses

tersebut. Memandangkan banyak fenomena agak sukar untuk dikaji melalui

eksperimen, satu pemahaman menyeluruh terhadap proses Pembentukan Ledakan

Hidro (EHF) telah tercapai melalui simulasi berangka melalui kajian ini.

Perilaku spesimen di bawah muatan bahan ledakan telah diramalkan mengikut

persamaan Johnson-Cook (JC), Zerilling-Armstrong (MZA) diubahsuai dan Plastic-

Kinematic (PK), yang telah digunakan untuk mengkaji taburan terikan seluruh

produk akhir. Selain itu, tiga teknik diperiksa secara berangka yang melibatkan

peningkatan nisbah antara ketebalan dan diameter plat kunci, menggunakan

pemegang dan alur pada hujung bahan kerja untuk mengurangkan kedutan.

© COPYRIG

HT UPM

VII

ACKNOWLEDGEMENTS

I hereby convey my heartfelt appreciation to my honored supervisor Assoc. Prof. Dr.

Aidy Ali and co-supervisor Dr. Azmah Hanim Mohamed Ariff. That without their

invaluable supports and worthwhile advices I will not be able to complete this work.

Also I would like to express my gratefulness to Tn. Hj. Mhd. Yunin Hassan, my

former supervisor, and all other faculty members who helped me to complete this

dissertation.

Furthermore, I would like to extend my appreciation to Dr. S. Borji as a pioneer in

explosive metal working field, who affiliated me with explosive forming and

encouraged me to work on this topic.

Finally, I have to express my sincere gratitude to my beloved father, Hossein

Jabalamelian, who supports me with his overwhelming efforts.

© COPYRIG

HT UPM

VIII

I certify that a Thesis Examination Committee has met on 10 January 2012 to conduct the final examination of Saeed Jabalamelian on his thesis entitled “Numerical Analysis of Shock Wave Propagation and AL5083 Sheet Bulging in Explosive Hydro Forming Process” in accordance with the Universities and University College Act 1971 and the Constitution of the Universiti Putra Malaysia [P.U.(A) 106] 15 March 1998. The Committee recommends that the student be awarded the Master of Science. Members of the Thesis Examination Committee were as Follows: Shamsuddin Sulaiman, PhD Professor Faculty of Engineering Universiti Putra Malaysia (Chairman) B. T. Hang Tuah bin Baharudin, PhD Senior Lecturer Faculty of Engineering Universiti Putra Malaysia (Internal Examiner) Barkawi bin Sahari, PhD Professor Faculty of Engineering Universiti Putra Malaysia (Internal Examiner) Shahrum Abdullah, PhD Professor Faculty of Engineering and Built Environment Universiti Kebangsaan Malaysia (External Examiner)

SEOW HENG FONG, PhD Professor and Deputy Dean School of Graduate Studies Universiti Putra Malaysia

Date: 23 April 2012

© COPYRIG

HT UPM

IX

This thesis was submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfilment of the requirement for the degree of Master of Science. The members of the Supervisory Committee were as follows:

Aidy bin Ali, PhD Professor Madya Faculty of Engineering Universiti Putra Malaysia (Chairman)

Azmah Hanim bt. Mohamed Ariff, PhD Senior lecturer Faculty of Engineering Universiti Putra Malaysia (Member)

BUJANG BIN KIM HUAT, PhD Professor and Dean School of Graduate Studies Universiti Putra Malaysia

Date:

© COPYRIG

HT UPM

X

DECLARATION

I declare that the thesis is my original work except for quotations and citation which have been duly acknowledged. I also declare that it has not been previously, and is not concurrently, submitted for any other degree at Universiti Putra Malaysia or other institutions.

_______________________

SAEED JABALAMELIAN Date: 10 January 2012

© COPYRIG

HT UPM

XI

TABLE OF CONTENTS

DEDICATION ABSTRACT ABSTRAK ACKNOWLEDGEMENTS APPROVAL DECLARATION LIST OF FIGURES LIST OF TABLES LIST OF ABBREVIATIONS LIST OF SYMBOLS

Page

ii iii v

vii viii x

xiii xvi xvii xix

CHAPTER 1

2

INTRODUCTION 1.1 Introduction 1.2 Problem Statement 1.3 Research Objective 1.4 Scope of Study 1.5 Layout of Thesis LITERATURE REVIEW 2.1 Introduction to High Rate Energy Forming 2.2 Explosive Metal Working Operations 2.2.1 Explosive Forming 2.2.2 Explosive Welding - Explosive Cladding - Explosive Bonding 2.2.3 Explosive Hardening 2.4.4 Reliving Residual Stresses 2.3 Advantageous, Limitations and Qualifications of Explosive Forming 2.4 Spheroid - Conical Section 2.4.1 Free Forming Method 2.4.2 Explosive Forming with Female Die 2.4.3 Explosive Forming with Male Die 2.5 Metal forming by Shock Wave 2.6 Strain rate, Temperature Sensitive Constitutive Equation 2.6.1 The Johnson-Cook (JC) model 2.6.2 The Zerilli-Armstrong model 2.6.3 The Steinberg-Guinan model 2.6.4 The Steinberg-Lund model 2.6.5 The Mechanical Threshold Stress (MTS) Model 2.6.6 The Preston-Tonks-Wallace (PTW) model 2.6.7 The Plastic-Kinematic model

1 1 2 5 5 6 8 8 15 15 20

23 25 25

29 30 31 33 34 36

37 43 45 48 50 54 58

© COPYRIG

HT UPM

XII

3

4 5

2.7 Discussion METHODOLOGY 3.1 Configuration of the Model 3.1.1 Material properties 3.2 Developing the Finite Element Model 3.2.1 Modeling the Configuration 3.2.2 Define the problem nature and mesh generation 3.2.3 Introducing the Materials Properties 3.2.4 Modeling the behavior of water and air 3.2.5 Modeling the explosive charge 3.2.6 Set the Boundary and Initial Condition 3.2.7 Check the Model 3.2.8 Final Model 3.2.9 Modifications and Assumptions 3.3 Discussion RESULTS AND DISCUSSION 4.1 Investigation the Shock Waves 4.2 Investigation the Expansion-Contraction Cycle 4.3 Investigation the Cavitations 4.4 Investigation the Pressure Profile 4.5 Deformation Mechanism 4.5.1 First Group (D = 120 mm, t = 3.3 mm) 4.5.2 Second Group (D = 140 mm, t = 3.2 mm) 4.5.3 Third Group (D = 140 mm, t = 2.2 mm) 4.5.4 Fourth Group (D = 120 mm, t = 3.3 mm with

circumferential grooves) 4.6 Summary CONCLUSIONS AND RECOMENDATIONS 5.1 Conclusions 5.2 Recommendations for Future Research

58

60 62 64 66 66 67 69 72 76 78 80 80 82 84

86 86 94 95 99 101 101 102 107 110

115

117 117 118

REFERENCES APPENDIXS BIODATA OF THE STUDENT

120 128 131