Application of Composites in Sporting Goods Prepared by: Dilpreet Bajwa Chad Ulven Chris Dahlen James Helphrey

Stone Age -> Bronze Age -> Iron Age -> Composite Age Composite Materials They can be defined as a material with two (or more) distinct macroscopical phases. Fibers embedded in or bonded to a matrix with distinct interfaces between the two constituent phases Eg. Concrete Matrix Silver – Copper Alloy reinforced with Carbon Fibers Iron Bars in the Cement Matrix Dispersed Phase Stone Age -> Bronze Age -> Iron Age -> Composite Age

Reasons for Composite Tailored Properties Lightweight High Strength Specific Strength High Stiffness High Strength Design Flexibility Vibration Damping

Laminated Fiberglass Bow Uses of Composites Composite Bicycle Laminated Fiberglass Bow Graphite Snowboard

Uses of Composites Composite Baseball Bat from Miken Sports

Uses of Composites

Uses of Composites Sports Skis Snowboards Snowboard Bindings Inline Skates Nordic Skis Nordic Ski Poles Nordic Ski Boots Snowshoes

Uses of Composites Composite Fishing Rods

Uses of Composites Dodge Viper Front grill of an Automobile Different part of an airplane

Composite Blade

Types of Fibers and Architecture Fiber Glass Graphite Fiber Kevlar Fiber Kevlar/Carbon Hybrid

Composite Materials Polymer – Thermoset, Thermoplastic, Elastomer Metallic – Al, Ti, Mg, and Cu Alloys Ceramic – Si Alloys Polymer (Thermoset) – Epoxy, Polyester, Vinyl Esters Fibers – Glass, Carbon, Graphite, Natural fibers (flax, sisal, cotton, hemp etc)

Laminated Composites Laminated composites can be thought of as sheets of continuous fiber composites laminated such that each layer has the fiber oriented in a given direction.

Basic Strength of Materials Stress: Stress is defined as the average force per unit area. Strain: A deformation produced by stress. It’s the ratio of difference in length to the actual length. Strain is always dimensionless.

Basic Mechanics Mechanics: Branch of engineering that studies internal effects of stress and strain in a solid body subjected to external loading. a) Statics - branch of mechanics which considers the action of forces in producing rest or equilibrium of a body. b) Dynamics - branch of mechanics which treats of the motion of bodies (kinematics) and the action of forces in producing or changing their motion (kinetics). Force: The capacity to do work or cause physical change. Pressure: Force applied uniformly over a surface, measured as force per unit of area.

Rules Of Mixture

Composite Fabrication Types of Composite fabrication: Wet Lay-up/Hand Lay-up Filament Winding Pultrusion Spray Lay-up Resin Transfer Moulding (RTM) Vacuum Assisted Resin Transfer Moulding (VARTM)

Hand Lay-up Resins are impregnated by hand into fibres which are in the form of woven, knitted, stitched or bonded fabrics. This is usually accomplished by rollers or brushes, with an increasing use of nip-roller type impregnators for forcing resin into the fabrics by means of rotating rollers and a bath of resin. Laminates are left to cure under standard atmospheric conditions.

Filament Winding This process is primarily used for hollow, generally circular or oval sectioned components, such as pipes and tanks. Fibre tows are passed through a resin bath before being wound onto a mandrel in a variety of orientations, controlled by the fibre feeding mechanism, and rate of rotation of the mandrel.

Skis Layout Process

Glass Fiber Types

Layout of Glass Fiber Sheets

Activity 1. Preparation of Composite Hockey Stick Material – Wooden hockey stick, Glass fiber sheets, Natural fiber mat, Adhesive, Gloves Procedure: Using the sand paper provided sand all sides of the hockey stick where fiber mats will be placed (marked section). Tightly layout the glass fiber sheets on the marked section of hockey stick and apply the adhesive with the roller. Be sure to wear the gloves and goggles and apply adhesive in the marked section area. Wait 1 hr for the adhesive to dry and cure. Do not move the samples once they are set aside for curing. Remove the samples from plastic sheet for testing.

Activity 1a. Testing of Composite Hockey Stick Material – Hockey Stick, Composite Blade, 2 Tables, Bucket with weight, Scale and Caliper Procedure: The hockey blade will be placed between two tables. A bucket with known weight will hang from the middle of the shaft of the hockey stick. Weights will be added to measure the deflection of composite versus regular wood hockey stick. The deflection and load values obtained will be used to measure the elastic properties of two different hockey sticks.

Activity 2. Design fiber reinforced composite plaques Material – Glass fiber mats, thermoset resin weighing scale and Caliper Procedure: Select 4 sheets of unidirectional fiber mats and 4 sheets of bidirectional mats. Lay 4 unidirectional glass fiber mats on polyethylene sheets. Lay 4 bidirectional glass fiber mats on polyethylene sheet. Impregnate them with thermoset resin using plastic bottle and roller. Cure the samples for 1.5 hrs. Conduct a drop ball impact test on the cured samples.

What did you learn? 1. What are composites and why use them? 2. How were the concepts of specific strength and specific stiffness used in today’s activity? 3. How does fiber reinforcement affect the properties? 4. What kind of fiber orientation did and didn’t work? 4. Why do think it did not work? 5. Describe the important strategies needed for designing a good composite good.

Future Directions The natural and eco element is gaining momentum. Recycling Natural Composites Cost/ Processing issues may gain more importance Composite Applications Video http://www.youtube.com/watch?v=Yw7DXelqd1c