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ٍٍالقمر 14-13
STRUCTURAL JOINTS IN
POLYMERIC COMPOSITE MATERIALS
. 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.
LAYOUT
INTRODUCTION JOINTS ------ COMPOSITES MECHANICALLY FASTENED JOINTS Kt
------ FAILURE MODES
SNAP JOINTS BONDED JOINTS Fusion Bonding for Joining Thermoplastic Matrix Composites ADHESIVE BONDED SIMILAR/DISSIMILAR MATERIALS.
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
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