UNIVERSITI PUTRA MALAYSIA CRUSHING BEHAVIOR OF …psasir.upm.edu.my/id/eprint/5920/1/FK_2004_38(1-24).pdfFaculty: Engineering An experimental and finite element analysis was carried

UNIVERSITI PUTRA MALAYSIA

CRUSHING BEHAVIOR OF HEXAGONAL COMPOSITE TUBES

MUNIR FARAJ M. ALKABIR.

FK 2004 38

CRUSHING BEHAVIOR OF HEXAGONAL COMPOSITE TUBES

BY

MUNIR FARAJ M. ALKABIR

Thesis Submitted to the School of Graduate Studies, Universiti Putra Malaysia, in Fulfilment of the Partial Requirements for the Degree of Master of Science

March 2004

DEDICATION

This work is dedicated

To my family

Parents brothers sister and to my wife and daughter

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

CRUSHING BEHAVIOR OF HEXAGONAL COMPOSITE

TUBES

BY


March 2004

Chairman: Associate Professor Abdel Magid Salem Hamouda, Ph.D.

Faculty: Engineering

An experimental and finite element analysis was carried out to investigate effect of

hexagonal composite tube dimension on failure mode and energy absorption capability.

Throughout this investigation, the hexagonal tube with different aspect ratio of length to

thickness (Llt) varying from 30 to 100 and different hexagonal angles varying from 35"

to 60" in 5" increments were investigated under the axial load condition. All the

hexagonal tubes tested were fabricated from fabric plain weave /epoxy.

The effect of hexagonal geometry on the load carrying capacity and energy absorption

capability was presented. A finite element model to predict the load carrying capacity,

deformation mesh, stress contours at pre-crush stage of hexagonal tube under an axial

load condition were developed.

Experimental results show that the hexagonal geometry (length to side diminutions)

increases the load carrying capacity by 32.0, 13.8, 2.land 18.7% respectively for

hexagonal side angle of 35", 45", 50°, and 55" respectively, the load carrying capacity is

reduce by 49.6 and 29.6% for hexagonal side angles of 4O0and 6O0repectively. The

energy absorption also increases by 1.42 and 1.5 % for hexagonal side angles of 35" and

6O0respectivelyand energy absorption is reduced by 48.6, 11.6, 20.0and 46,7%

respectively for hexagonal side angle of 40°, 45", 50" and 55" respectively. Finite

element model predictions are correlated with experimental results. The variation

between the experimental and finite element is in the range of 5.9% to 9.8% .The effect of

geometry of fabric plain weavelepoxy (Ring Chain System With Hexagonal Shape) on

crushing behavior, energy absorption capability, crush failure loads and failure modes

were also investigated.

Failure modes were examined using several photographs taken during the crushing

stages for each experiment. The main failures modes that occured during the experiment

are local buckling, catastrophic and matrix failure modes.

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

KELAKUAN PENGHANCURAN BAG1 TIUB KOMPOSIT HEKSAGON

Oleh


Mac 2004

Pengerusi: Profesor Madya Abdel Magid Salem Hamouda, Ph.D.

Fakulti : Kejuruteraan

Satu eksperimen dan analisis unsur terhingga telah dijalankan bagi mengkaji kesan

dimensi t iub k omposit h eksagon k e a tas r agam kegagalan d an k eupayaan p enyerapan

tenaga. Sepanjang kajian ini, tiub heksagon dengan nisbah bidang yang berbeza bagi

panjang lawan ketebalan (Llt) berubah daripada 30 kepada 100 dan sudut-sudut

heksagon yang berbeza berubah daripada 35" kepada 60" pada tokokan 5" telah dikaji di

bawah keadaan beban paksian.

Kesemua t iub h eksagon yang d iuji t elah d ibikin d aripada j alinan b iasa fabriklepoksi.

Kesan geometri heksagon ke atas keupayaan membawa beban dan keupayaan

penyerapan tenaga telah dipersembahkan. Satu model unsur terhingga bagi meramal

keupayaan membawa beban, jejaring ubah bentuk dan kontor-kontor tegasan pada tahap

pra-hancur bagi tiub heksagon di bawah keadaan beban paksian telah dibangunkan.

Keputusan-keputusan eksperimen menunjukkan bahawa geometri heksagon (panjang

lawan pengecilan sisi) menambah keupayan membawa beban sebanyak 32.0, 13.8, 2.1

dan 18.7 bagi sudut sisi heksagon 35', 45", 50' dan 55". Keupayaan membawa beban

telah dikurangkan sebanyak 49.6 dan 29.6 bagi sudut-sudut sisi heksagon 400 dan 600.

Penyerapan tenaga juga bertambah sebanyak 1.4 dan 1.5 bagi sudut-sudut sisi heksagon

35' dan 60' dan penyerapan tenaga telah dikurangkan sebanyak 48.6, 1 1.6,20.0 dan 46.7

bagi s udut s isi h eksagon 4 0 O, 4 5 ', 5 0 ' d an 5 5 '. P eramalan-peramalan model unsur

terhingga telah dikorelasi dengan keputusan-keputusan eksperimen. Variasi antara

eksperimen dan unsur terhingga ialah dalam julat 5.9 ke 9.8. Kesan goemetri bagi

jalinan biasa fabriklepoksi (sistem rantai cincin dalam bentuk heksagon) ke atas

kelakuan penghancuran, keupayaan menyerap tenaga, beban-beban kegagalan hancur

dan ragam-ragam kegagalan telah juga dikaji.

Ragam-ragam kegagalan telah diperiksa menggunakan beberapa gambarfoto yang

diambil semasa tahap-tahap penghancuran bagi setiap eksperimen. Ragam-ragam

kegagalan yang utama yang berlaku semasa eksperimen adalah lengkokan setempat,

ragam kegagalan bencana dan ragam kegagalan matriks.

ACKNOWLEDGEMENTS

In the name of Allah, Most Gracious, Most Merciful

First, by the grace of Allah (sbt), the controller of the whole universe, who has provided

me with good health to finish this work in time. Secondly, I would like to express my

sincere gratitude to the Chairman of the Supervisory Committee Assoc. Prof. Dr. Abdel-

Magid Salem Hamouda for his continuous help, support and encouragement throughout

this work.

I would like to express my appreciation to Dr. Elsadig Mahdi for his suggestions and

constructive criticisms given at different stages of this study.

I also wish to thank Assoc. Prof. Ir. Dr. Mohd Sapuan Salit for his necessary help,

guidance and valuable suggestions.

I also wish to express my thanks to my friends in Faculty of engineering for their

cooperation. Special thanks goes to Mr. Manshwi Kames Alkhey for his help.

I a m grateful to my country Libya for having offered me a scholarship to pursue the

graduate study at university Putra Malaysia. Special thanks go to all the lovely members

of my family and relatives with out whose encouragement and overwhelming support to

complete this study.

vii

1 certify that an Examination Committee met on 5h March 2004 to conduct the final examination of Munir Faraj M. Alkabir on his Master of Science thesis entitled "Crushing Behavior of Hexagonal Composite Tubes" in accordance with Universiti Pertanian Malaysia (Higher Degree) Act 1980 and Universiti Pertanian Malaysia (Higher Degree) Regulations 198 1. The Committee recommends that the candidate be awarded the relevant degree. Members of the Examination Committee are as follows:

Shamsuddin Sulaiman, Ph.D. Associate Professor Faculty of Engineering Universiti Putra Malaysia (Chairman)

P.R. Arora, Ph.D. Associate Professor Faculty of Engineering Universiti Putra Malaysia (Member)

Yousf A. Khalid, Ph.D. Associate Professor Faculty of Engineering Universiti Putra Malaysia (Member)

Ahmad Kamal Ariffin, Ph.D. Associate Professor Department of Mechanical Engineering Faculty of Engineering Universiti Kebangsaan Malaysia (Independent Examiner)

ProfessorIDeputy Dean School of Graduate Studies Universiti Putra Malaysia

Date: 1 7 JUN 2004

... Vlll

This thesis submitted to the Senate of Universiti Putra Malaysia and has been accepted as fulfillment of the partial requirements for the degree of Master of Science. The members of the Supervisory Committee are as follows:

Abdelmagid Salem Hamouda, Ph.D. Associate Professor Faculty of Engineering Universiti Putra Malaysia (Chairman)

Elsadig Mahdi Ahmed, Ph.D. Faculty of Engineering Universiti Putra Malaysia (Member)

Ir. Mohd Sapuan Salit,P.h.D. Associate Professor. Faculty of Engineering Universiti Putra Malaysia (Member)

AINI IDERIS, Ph.D. Professor1 Dean School of Graduate Studies Universiti Putra Malaysia

Date: - 4 AUG 20M

DECLARATION

I hereby declare that the thesis is based on my original work except for quotations and citations, which have been duly acknowledged. I also declare that it has not been , previously or concurrently submitted for any other degree at UPM or other institutions

Munir Faraj M. ~ l k b i y

Date: - 2 JUL 2004

TABLE OF CONTENTS

Page

DEDICATION ABSTRACT ABSTRAK ACKNOWLEDGEMENTS APPROVAL DECLARATION LIST OF TABLES LIST OF FIGURES LIST OF NOMENCLATURE

CHAPTER

INTRODUCTION 1.1 General Introduction 1.2 Research Objectives 1.3 Significance of the Study 1.4 Thesis Layout

LITERATURE REVIEW 2.1 Introduction 2.2 Composite Materials

2.2.1 Fibers 2.2.2 Glass Fibers 2.2.3 Matrices

2.3 Fabrication Methods of Composite Shells 2.3.1 Hand lay-up 2.3.2 Filament Winding

2.4 Energy Absorption Capability in Composite Material 2.4.1 Various Variables that Influence the Energy absorption

Characteristics of Composite Material 2.5 Crushing Modes and Mechanisms

2.5.1 Catastrophic Failure Modes 2.5.2 Progressive Failure Modes

2.6 Failure Mechanisms 2.7 Crashworthiness Parameters in Composite Materials

2.7.1 Initial peak Load 2.7.2 Mean-Crushing Load 2.7.3 Crush Force Efficiency 2.7.4 Stroke Efficiency

v11 . . .

V l l l

X ...

X l l l

xiv xviii

2.7.5 Initial Failure Indictor 2.7.6 Specific Energy Absorption

2.8 Conclusion

METHODOLOGY 3.1 Experimental work 3.1 Geometry 3.2 Materials 3.3 Fabrication Process 3.4 Loading Condition 3.5 Test Procedure 3.6 Finite Element Simulation

EXPERIMENTAL RESULTS 4.1 Introduction 4.2 Hexagonal Tube under Quasi-static Axial Crushing Load

4.2.1 Hexagonal Tube With Aspect Ratio (L/t=30) and different Angles (H.30.AP)

4.2.2 Hexagonal Tube With Aspect Ratio (L/t=50) and different Angles (H.50.Ap)

4.2.3 Hexagonal Tube With Aspect Ratio (L/t=70) and different Angles (H.70.AP)

4.2.4 Hexagonal Tube With Aspect Ratio (L/t=100) and different Angles (H. 100.AP)

4.3 Ring Chain System of Hexagonal Shape With Various Angles 4.3.1 Load-Displacement Relation 4.3.2 Specific Energy Absorption Capability-Displacement

Relation 4.3.3 Crushing History and Failure Modes 4.3.4 Summary

FINITE ELEMENT RESULTS 5.1 Finite Element Method 5.2 Composite Hexagonal Tubes Modeling 5.3 Boundary Condition and Material Properties 5.4 Finite Element Result and Comparison with Experimental results

CONCLUSIONS AND SUGGESTION FOR FUTURE WORK

REFERENCES BIODATA OF THE AUTHOR

xii

LIST OF TABLES

Table Page

Specific energies of thermoplastic composite tubes with different fibers

Mechanical properties of different resin

Description of the fabric plain weave Hexagonal tubes

Description of the ring chain system of hexagonal shape

Type of composite material and matrix

Crashworthiness parameters for Hexagonal composite tube with

aspect ratio (L/t=30) and various angles

Crashworthiness parameters for Hexagonal composite tube with aspect ratio (L/t=50) and various angles



Crashworthiness parameters for Ring chain system of hexagonal Composite shape with various angles

Typical engineering properties of materials used in this study

Prediction of initial crush failure load (Pi)

. . . X l l l

LIST OF FIGURES

Figure Page

Variation of specific energy of carbon fiber1PEEK tubes with fiber Orientation (8) Load-Stroke curve: crush speed

Schematic diagram of a composite tube specimen with one end Chamfer trigger Composite tubes crushed progressively a) fragmentation b) Splaymg modes Crushing characteristics of brittle fracturing crushing mode

Local buckling crushing mode

Micro-level failure mechanisms

Schematic diagram of a typical force displacement curve

Typical load-displacement curve for a progressively crushed

Composite tube

Flow chart describes the methodology used in this study

Chart describes the experimental work

(a) Cross sectional area (b) ring chain system of hexagonal shapes

Schematic diagram for fabric plain weave fabrication process

Schematic representation of the loading Conditions

Flow chart describes the finite element work

Load- displacement curves for hexagonal composite tube with aspect Ratio (Wt = 30) and various angles (35", 40°, 45", 50°, 55" and 60") Relations between hexagonal angles and average load

Specific energy -displacement curve for hexagonal composite tubes

with aspect ratio L/t=30 and different angles

Typical load-displacement and crushing history for (H.30.35")

Typical load-displacement and crushing history for (H.30.40°)



Typical load-displacement and crushing history for (H.3O.55 ")

xiv

Typical load-displacement and crushing history for (H.30.6Oo)

Load- displacement curves for hexagonal composite tube with aspect

ratio (LIt = 50) and various angles (35", 40°, 45", 50°, 55" and 60")

Relations between hexagonal angles and average load


with aspect ratio L/t=50 and different angles.








ratio (Llt = 70) and various angles (35", 40°, 45", 50°, 55" and 60")

Relations between hexagonal angles and average load


with aspect ratio L/t=70 and different angles

Typical load-displacement and crushing history for (H.70. 35")

Typical load-displacement and crushing history for (H. 70.40")






ratio L/t= 100 and various angles (35", 40°, 45", 50°, 55" and60°)

Relations between hexagonal angles and average load (kN)

Specific energy absorption capability -displacement curves for Hexagonal composite tubes with aspect ratio (Llt=100) and different angles Typical load-displacement and crushing history for (H. 100. 35")

Typical load-displacement and crushing history for (H. 100. 40")

Typical load-displacement and crushing history for (H. 100. 45")

4.34 Typical load-displacement and crushing history for (H. 100. 50")

4.35 Typical load-displacement and crushing history for (H.100. 55")

4.36 Typical load-displacement and crushing history for (H. 100. 60")

Load- displacement curves for ring chain system of hexagonal shape

with P=(35", 40", 45", 50°, 55" and 60")

Average Load- displacement curves for ring chain system of

hexagonal P=(35", 40°, 45", 50°, 55" and 60")

Specific energy absorption capability - displacement curves for ring

chain system of hexagonal shape with (P=35", 40°, 45", 50°, 55" and

60")

Load-deformation curve of ring chain system of hexagonal composite

shape with P=3 5 "


shape with P=40°


shape with P=45"


shape with P=50°


Shape with P=55"

Load-deformation curve of ring chain system of hexagonal composite Shape with P=60" 108

Flow chart describes the Eigenvalue analysis using LUSAS finite

element program

Typical mesh for axially loaded of composite hexagonal Tube

Experimental and finite element deformed mesh together with stress

contours for axially loaded composite tube with aspect ratio (L/t=30

and P=55")


contours for axially loaded composite tube with aspect ratio (L/t=50

and P=45")

xvi


contours for axially loaded composite tube with aspect ratio

(L/t=70and P=45")


contours for axially loaded composite tube with aspect ratio

(L/t=l OOand P=50°)

xvii

LIST OF NOMENCLATURE

Cross sectional are of hexagonal tube

Dimension of hexagonal tube

Crush force efficiency

Specific energy absorption

Initial failure indicator

Aspect ration of hexagonal tube

Weight of the specimens

s E Stroke efficiency

I3 Hexagonal angle

(H. A Llt. A p) hexagonal tube with different aspect ratio (Llt) different angles varying

PC, Critical crushing load

Pi Initial crushing load

Mean - crushing load

xviii

CHAPTER 1

INTRODUCTION

1.1. General Introduction

Materials have such an influence on our lives that the historical period of humankmd

have been dominated, and named, after materials over the last thirty years, composite

materials, plastics, and ceramics have been the dominant emerging materials. The

volume and number of applications of composite material has grown steadily,

penetrating and conquering new markets (relentlessly).

Composite materials are formed by a combination of two or more materials to achieve

properties (physical, chemical, ect) that are superior to those of its constituent. The main

components of composite material, or composites, are fiber and matrix. Fiber provides

most of the stiffness and strength, and the matrix binds the fiber together thus providing

load transfer between fiber and between the composite and the external loads and

supports. The matrix is the principal phase in which other constituents (e.g.,

reinforcement, or fillers) are embedded or surrounding the reinforcement is material

used to reinforce, strengthen or give dimensional stability.

The reasons for choosing composites in automotive applications include lower weight

and greater durability (improved corrosion resistance, fatigue life, wear and impact

resistance). Applications include drive shafts, fan blades, tires, brake shoes, clutch

plates, gaskets, hoses, belts, and engine parts hybrid composite drive shaft for trucks

manufactured by pultrusion where carbon and glass fiber composite are pultuded over

aluminum cylinder to create a drive shaft that is significantly lighter and less expensive.

The use of advanced composites in structures such as bridges and buildings has lagged

behind applications in other areas. One major reason for this is that weight is not an

important consideration in static structures. However, as the benefits of reduced. An

interesting example is the use of maintenance and erection costs combine with

architectural enhancements are recognized, the application of composite in these

structures will follow. Composites are also in use in lightweight overhead walkways, as

well as lighting and communications poles [I].

Composite tube is common structural components that can be used for a wide variety of

applications. Some of these applications include oil pipelines, trusses for space vehicles

and chassis of automobiles. Composite materials offer the stiffness of conventional

metal at a lower weight. With this viewpoint, the automotive industry is currently

exploring to adapting more fiber reinforced polymer matrix composites into automobile

bodies. The amount of energy that vehicle absorbs during a collision is a matter of

concern to ensure safer and more reliable vehicles. If composite can be economically

manufactured and be made to offer equivalent energy absorption under impact as metals

at a fraction of the weight, the savings to both automakers and consumers would be

substantial.

Investigations of crushing energy absorption are important and are expected from the

point of view of safety design of passenger vehicles. In order to reduce the damage to

occupants in a collision, it necessary to understand the crushing behavior and to enhance

the energy absorbing capability of tubular structures [2]. In passenger vehicles the ability

to absorb impact energy and be survivable for the occupant is called the

"crashworthiness" of the structure. This absorption of energy is through controlled

failure mechanisms and modes that enable the maintenance of a gradual decay in the

load profile [3].

Usually the experimental analysis is more common, but finite element also is getting a

great attention for its quick results. The effect of the number of layers, type of the fiber,

type of the matrix and fiber orientation angles were the common features which are

usually evaluated for each structure by developing the load-displacement and energy

absorption relation. Several researches were carried out on composite materials and

structures to evaluate their properties, strength, and behavior structures including

cylinders plats, and cones, which were tested experimentally and theoretically.

Throughout this investigation, the investigation of energy absorption capability in

hexagonal composite tube is carried out experimentally and numerically under an axial

crashing load by using the finite element method. Also, the experimental validation has

been done in the crushing behavior of composite hexagonally ring system under lateral

cashing load. The effects of mandrel geometry on crashworthiness performance of fabric

plain weave /epoxy hexagonal tubes and ring chain system and their effects on energy

absorption capabilities have been observed.

1.2 Research Objectives

The main objectives of this work are:

To study the effects of geometry of hexagonal composite tube and ring chain

systems with hexagonal shape on crushing behavior.

To investigate the energy absorption capability of hexagonal composite tubes

and ring chain system with hexagonal shape

1.3 Significance of the Study

Composite materials are rapidly becoming potential substitutes for metal due to

their higher strength and stiffness-to-weight ratio, improved corrosion resistance,

styling enhancement and the reeducation of fabrication maintenance costs.

The efficient use of hexagonal composite tubes as energy absorber depends on

the understanding of their crushing behavior.

The generated data from this study can be useful in design phase of energy

absorber element made from composite material.

1.4 Thesis Layout

This thesis is divided into seven chapters. Following this introduction Chapter, chapter

two presents a review of literature related to matrix and reinforcement, advantages and

Classification of composite material. Crushing behavior and energy absorption

characteristics of composite structures are also discussed. The methodology used in this

study is explained in chapter three. Chapter four presents the experimental results. Finite

element results are presented and discussed in chapter five. Finally in chapter six,

conclusion from the work and the proposal for future studies are listed

CHAPTER 2

LITERATURE REVIEW

2.1 Introduction

In this chapter, literatures related to composite materials are reviewed. Attention is

directed towards, fabrication methods, energy absorption capability in composite

material, crushing modes and mechanisms and crashworthiness parameters in composite

materials are discussed in details.

2.2 Composite Materials

The general definition of composite material is very closely related to the dictionary

definition of the word composite, meaning made up of different parts or materials.

Composite materials are constructed from two or more materials, commonly referred to

as constituents, and have characteristics derived from the individual constituents.

Depending on the manner in which the constituents are put together the resulting

composite material may have the combined characteristics of the constituents, this

according to Gurdal, and Hajela [4].

Documents

UNIVERSITI PUTRA MALAYSIA CRUSHING BEHAVIOR OF …psasir.upm.edu.my/id/eprint/5920/1/FK_2004_38(1-24).pdfFaculty: Engineering An experimental and finite element analysis was carried