eg2011 machines

what does welding do

provides a permanent joint

what is a limitation of welding (work types)

performed manually so labor cost is expensive

what is a safety limitation of welding

utilizes high energy and is inherently dangerous

what is a limitation of welding (convenience)

welded joints don’t allow for convenient disassembly

what is a limitation of welding (defects)

welded joints can have quality defects that are difficult to detect

What type of weld joint is this?

inside single fillet corner joint

What type of weld joint is this?

outside single fillet corner joint

What type of weld joint is this?

double fillet lap joint

What type of weld joint is this?

double fillet t joint

What type of loading is this?

Parallel loading

What type of loading is this?

Transverse

What type of loading is this?

Transverse

What is the function of a clutch

to permit smooth gradual connection and disconnection of two members having a common axis of rotation

What is the difference between a clutch and brake

a break has one of its members fixed

What are the basic clutch and break requirements (torque)

friction torque must be produced by an actuating force

What are the basic clutch and break requirements (energy)

Energy converted to friction heat must be dissipated without destructive temperatures

What are the basic clutch and break requirements (life)

the surface wear must have an acceptable working life

What is a wet clutch

a clutch that uses oil as an effective coolant

how is are wet clutches modified so they have enough friction

using multiple disks to compensate for the reduced coefficient of friction

what types of clutches are usually dry

automotive clutches

what type of clutches are wet

automatic transmissions and most multiple disk clutches

what is a pro of welding (hardware)

no mechanical hardware is required

what is a pro of welding (material use)

most economical method of joining parts in terms of material usage

what is a pro of welding (location)

can be carried out anywhere

what is the adhesive

nonmetallic filler material, usually a polymer

what are adherends

the parts being joined

what are structural adhesives

adhesive of great interest in engineering that are capable of forming strong, permanent joints between strong rigid adherends

what does joint strength depend on

the strength of the adhesive and the attachment between the adhesive and adherends

what is chemical bonding (attachment mechanisms)

adhesive and adherent form primary bond on curing

what are physical interactions (attachment mechanisms)

secondary bonding forces between surface atoms

what is mechanical interlocking (attachment mechanisms)

roughness of adherend causes adhesive to become entangled in surface asperities

what should be maximised in joint design

joint contact area

what types of loads are adhesive joints strongest under

shear and tension

what types of loads are adhesive joints weakest under

cleavage and peeling

What type of stress is this

tension

What type of stress is this

peeling

What type of stress is this

cleavage

What type of stress is this

shear

what type of joints are these

butt joints

what type of joints are these

t joints

what type of joints are these

corner joints

Advantage of adhesives (stress distribution)

uniform stress distribution across entire bonded area

Advantage of adhesives (fatigue)

good fatigue resistance

Advantage of adhesives (vibration)

good vibration damping and flexibility

Advantage of adhesives (variety of bonding)

ability to bond aluminium to nonmetallic materials

Advantage of adhesives (weight)

weight reduction compared to bolts and rivet joints

Advantage of adhesives (surfaces)

smooth joint surfaces and contours

Advantage of adhesives (anodize)

ability to anodize with no risk of staining

Advantage of adhesives (corrosion)

prevention or reduction of galvanic corrosion

Advantage of adhesives (properties)

good sealing and insulating properties

Disadvantage of adhesives (high temps)

decrease strength at high temperatures especially under long time loading

Disadvantage of adhesives (environment)

possible degradation of bond by environmental influence

Disadvantage of adhesives (process)

complicated bonding process s stronger joints need proper surface preparation and may need jigs, presses and heating equipment

Disadvantage of adhesives (inspection)

difficult and expensive to provide for adequate inspection

Disadvantage of adhesives (health)

additional exhausts and protective clothing may be needed for health reason