Summaries after sample
,Sample
Summaries after sample
, Properties of various
Forces
construction materials
Static or dynamic loads
Physical properties: mass,
weight and density • Static forces don’t move.
• Dynamic forces move and change.
• Mass = a measure of the quantity of matter an
object has.
• Weight = a force caused by the attraction of 2
Even or uneven loads
objects with mass.
• w = mg. • Even load – weight is evenly distributed in
Sample
• Density = the relative heaviness of objects a structure.
with a constant volume. • Uneven load – weight in one part of the
structure is more than in another part.
U3: Structures
Mechanical properties: hardness,
Summaries after sample
•
•
ductility, stiffness and flexibility
Hardness = the property that allows a material to resist
being deformed.
Ductility = refers to how easily a metal is shaped into
•
Strength of materials under
the action of forces
Structures must be able to withstand tension,
compression, torsion, shear and bending.
sheets or wires. • Deflection (bending of a beam) depends on the
• Stiffness = inflexible and hard to bend. load, the planes and shape of the beam’s
• Flexibility = enables an object to be deformed without
Chemical: corrosion resistance cross-section.
being damaged.
and prevention of corrosion
• Properties of steel:
- Formability and durability.
- Good tensile strength.
- Good thermal conductivity.
- Resistance to corrosion on stainless steels.
• Corrosion occurs on surfaces exposed to oxidants.
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GR9
TECH T1-U3 Mind Map Via Afrika