Sample coding and value of areal density for different testing

viii LIST OF TABLES 2.1 Typical mechanical properties of fiber used in PMC 11 2.2 Differences between thermoset and thermoplastic 12 2.3 Properties of thermoplastic elastomers 13 2.4 Advantages and disadvantages of crosslinking 13 2.5 Types of laminates based on orientation 19 2.6 Advantages and disadvantages of thermoplastic and thermoset matrices 20 2.7 Specification of the filament and staple 21 2.8 Mechanical and physical properties of glass and kevlar fabric 21 2.9 Materials that commonly used based other researchers 22 2.10 The thickness and layer of the composite 23 2.11 Standard and machine used for anti stab testing 25 2.12 Results of the resin reinforced p-aramid fabric 28 2.13 Stab resistance test results for spike protection class energy level 1 to 3 29 2.14 Example results of stab resistance test for edge blade Protection class energy level 1-3 29 2.15 Overview of studies on anti stab 35 3.1 Mechanical properties of aramid fiber 38 3.2 Properties of E-glass fiber 40 3.3 Mechanical properties of HDPE 41 3.4 Mechanical properties of LDPE 42 3.5 Sample code for HDPE sample 44 3.6 Sample code for LDPE sample 45

4.1 Sample coding and value of areal density for different testing

53 ix LIST OF FIGURES 1.1 Flowchart of methodology 7 2.1 Classification of composite materials 10 2.2 Thermoplastic processing method 14 2.3 Lamina and laminates lay-ups 16 2.4 a The bidirectional b The unidirectional 17 2.5 Quasi-isotropic material lay-up 18 2.6 Quasi static knives penetration testing for multi axial composite 23 2.7 The compression jig for quasi static stab resistance testing 24 2.8 a Anti-stabbing test equipment drop tower type b Dimensional specification 24 2.9 Types of impactor a S1, b P1 and c spike 26 2.10 The hybrid multiaxial composites target 26 2.11 a Puncture impact b Dynamic puncture 27 2.12 The effect of the angle on the penetration 29 2.13 Photography of fabric damage on the STF-kevlar and kevlar 30 2.14 Image of back layer a Kevlar b STF- 30 2.15 a near the tip; b in the middle of the stab position; c near the blunt sides d near the tip 31 2.16 Static puncture observations of thickness-direction a G-CF, b K-CF, dynamic puncture observations of in-plane c G-CF and d K-CF 32 3.1 Flowchart of methodology 37 3.2 Kevlar 300 in satin weave type 39 3.3 Woven roving of E-glass fiber 39 3.4 HDPE in pellet form. 41 3.5 LDPE in pellet form. 41 3.6 Orientation of composite laminate 43 3.7 Laminate size a the laminate composite, b mould size 43 x 3.8 Hot press machine 46 3.9 Flowchart of hot press process. 47 3.10 a Quasi static machine testing and b jig 49 3.11 Three point of loading flexural testing 50 3.12 Scanning electron microscopy 51 4.1 7 layers of reinforcement for sample H3 54 4.2 11 layers of reinforcement for sample H5 56 4.3 Differences thickness and areal density of each sample. 57 4.4 Bending test for sample H5c a before test, b after test 58 4.5 Laminate composite damage at layer 6 of sample H5c. 59 4.6 Maximum force at strokedisplacement 10 mm 61 4.7 Schematic diagram of knives for stab test a P1, b S1. 62 4.8 Maximum force at displacement 20 mm 65 4.9 Maximum force at strokedisplacement 50 mm 66 4.10 Back side of sample L3a during penetration. 67 4.11 Back side failure of laminate composite after penetration 68 a H2a, b L5a 4.12 Schematic of impact damage mode for laminate composite 68 Shyr and Pan, 2013. 4.13 Schematic cross sectional view of fiber orientation and the 69 height after penetration 4.14 Height penetration distribution for laminate composite sample 70 4.15 Cross section after P1 penetration at displacement 20, 50 mm 71 a H3, b L5 4.16 Maximum force at strokedisplacement 50 mm 75 4.17 Cross section after S1 penetration at displacement 50 mm 76 a H5, b L5. 4.18 SEM images of the HDPE fabric target after quasi static stab 77 testing on sample H5. 4.19 SEM images of the LDPE fabric target after quasi 78 static stab testing on sample L5. xi LIST OF ABBREVIATIONS ASTM - American society for testing and materials EVA - Ethylene-vinyl acetate GFRP - Glass fiber-reinforced polymer GMT - Glass mat thermoplastic H1 - HDPE sample 3 H2 - HDPE sample 4 H3 - HDPE sample 5 H4 - HDPE sample 6 H5 - HDPE sample 7 HDPE - High Density Polyethylene HG - HDPE with glass fiber sample 2 HK - HDPE with kevlar sample 1 L1 - LDPE sample 3 L2 - LDPE sample 4 L3 - LDPE sample 5 L4 - LDPE sample 6 L5 - LDPE sample 7 LDPE - Lower Density Polyethylene LG - LDPE with glass fiber sample 2 LK - LDPE with kevlar sample 1 NIJ - National Institute Justice P1 - Small knife PE - Polyethylene PET - Polyethylene terephthalate PMC - Polymer matrix composite PP - Polypropylene PSM - Projek sarjana muda RTM - Resin transfer molding xii S1 - Large knife SEM - Scanning electron microscopy SiO 2 - Silicon oxide TPU - Thermoplastic polyurethane UHMWPE - Ultra high molecular weight polyethylene UTM - Universal testing machine xiii LIST OF SYMBOLS o - degree o C - degree celcius KPa - Kilo Pascal kN - Kilo Newton gcm 3 - gram per centimetre cubic in. - inch MPa - Mega Pascal µm - micro metre X - multiply - percent : - ratio mm - millimetre 1 CHAPTER 1 INTRODUCTION

1.1 Research Background