Joints in composite materials

‫بسم ا الرحمن‬ ‫الرحيم‬ ‫ت ٍاَ لأل ٍاَْو ٍ​ٍ​ٍادوَ ح‬ ‫ٍاَو ٍاَح ٍاَم ْل ٍاَن ع ُه ٍاَع ٍاَل ٍاَى ٍاَذٍ​ٍا ِ‬ ‫ٍاَو ع ُد ع ُس ٍر ٍاَ‬ ‫َ‬

‫ْجت ِر ي ِب ٍاَأ ْع ع ُي ِن ٍاَن ا ٍاَ ٍاَ​َجًءازٍ​ٍا ًء ِ ٍاَملك ن‬ ‫ك ِف َر‬ ‫ٍاَك ا ٍاَن ُ‬

‫ٍ​ٍالقمر ‪14-13‬‬

STRUCTURAL JOINTS IN

POLYMERIC COMPOSITE MATERIALS

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D .

Ph , m a l l a S y t i m s a r s e s v i o n H U y B ig z a Zag

Objectives The main goal of this review article is to present a sound background regarding the development of the understanding of the mechanical behavior and the failure modes of the mechanically fastened, snap, bonded, and hybrid joints in polymeric composite materials.

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LAYOUT

INTRODUCTION JOINTS ------ COMPOSITES MECHANICALLY FASTENED JOINTS Kt

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------ FAILURE MODES

SNAP JOINTS BONDED JOINTS Fusion Bonding for Joining Thermoplastic Matrix Composites ADHESIVE BONDED SIMILAR/DISSIMILAR MATERIALS.

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HYBRID JOINTS

Introduction STRUCTURAL JOINTS

COMPOSITE MATERIALS

Introducti on

Classification Of Composite Materials W.R.T Reinforcement Forms

W.R.T Type of Matrix

•Particle

•Polymers

•Fiber Discontinuous Continuous •Laminate

•Metals •Ceramics

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INTRODUCTION MECHANICALLY FASTENED JOINTS SNAP JOINTS BONDED JOINTS HYBRID JOINTS CONCLOUSIONS

MECHANICALLY FASTENED JOINTS Single lap bolted joint

Double Strap bolted joint

Types of Circular Hole in Tensioned FRP Plates •OPEN-HOLE TENSION •FILLED-HOLE TENSION WITH/WITHOUT A CLAMP-UP LOAD. •BOLTED JOINT, BOLT-LOADED HOLE WITH/WITHOUT CLAMP-UP LOAD.

Tab

Tab

Rigid Washer

Load Cell

Washer D

Dw

Nut

Load Cell

Washer

Bolt

W

Specimen

W

(a)

(b)

Strain Gauge

(c)

FAILURE MODES OF OPEN-HOLE TENSION PLATES

Fiber Breakage Matrix Cracking Delamination

Fiber-Matrix Splitting

FAILURE MODES OF BOLTED JOINTS σf/ َo = 0.8 Steel

e

σf/ َo < 0.5 FRP P

Net-Tension َN = P /([W-dH]t) P Shear-Out

َSO = PSO /(2et) PَSO = fult (et)

P

Transverse

USA

splitting

P

Cleavage

PَSO=fult (et)/1.2

Euro

PَSO=fult [0.6(e-dH/2)2t]

P

CAN

Bearing

َb = P /(dBt)

Pull-out

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INTRODUCTION MECHANICALLY FASTENED JOINTS SNAP JOINTS BONDED JOINTS HYBRID JOINTS CONCLOUSIONS

SNAP JOINTS

SNAP JOINTS

(a) Composite Transmission Tower

(b) Truss Joint

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INTRODUCTION MECHANICALLY FASTENED JOINTS SNAP JOINTS BONDED JOINTS HYBRID JOINTS CONCLOUSIONS

Fusion Bonding Techniques Bulk Heating

Co-consolidation Hot-melt Adhesives Dual Resin Bonding

Frictional Heating

Spin Welding Vibration Welding Ultrasonic Welding

Electromagnetic Heating Induction Welding Microwave Heating Dielectric Heating Resistance Welding

Two-stage Techniques

Hot Plate Welding Hot Gas Welding Radiant Welding Infrared Welding Focused Infrared Welding Laser Welding Solar Energy

BONDED JOINTS ADHESIVE-1 •Single lap

•Double lap

•Double strap

BONDED JOINTS

ADHESIVE-2

Stepped lap Double stepped lap Single scarf Double scarf

A

A

T700 carbon/epoxy

ALâ&#x20AC;&#x201C;6XN steel

ADHESIVE-3

BONDED JOINTS

The general geometric parameters for a tongue-and-groove joint.

New design with flat, pointed inserts

Wavy-lap joint main dimensions

Prevention of Peeling failure in Adhesive Joints Peel action

Increase area

Increase stiffness

Bead end (if possible)

Rivet, bolt or spot weld

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INTRODUCTION MECHANICALLY FASTENED JOINTS SNAP JOINTS BONDED JOINTS HYBRID JOINTS CONCLOUSIONS

HYBRID JOINTS

Retrofitting schemes

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INTRODUCTION MECHANICALLY FASTENED JOINTS BONDED JOINTS SNAP JOINTS HYBRID JOINTS CONCLOUSIONS

CONCLUSIONS 

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All joining methods present advantages and drawbacks, and they may be more or less suitable to particular application depending on its specific requirements.

Well-established joining technologies for metallic structures are not directly applicable to FRP. Some adhesives are disposed to degradation by temperature and humidity.

Hybrid joints give better static as well as fatigue performance than adhesive joints in composites.

‫الحمد لله رب‬ ‫العالمين‬ ‫وشكراَ‬