Materials and Constraints

The 5 Exterior Forces

Tension Compression Torsion Shearing Bending

Constraints

effects caused inside a material by an external force which tends to deform it

Application of the force application of the force of tension the effects of an identical force of compression will not be the same if the

thickness is different

Types of ConstraintsConstraint Definition ExamplesTension Tensile stress is

formed in a material which undergoes a force tending to lengthen it

Compression Compressive stress is formed in a material which undergoes a force tending to compress it

Torsion Torsional stress is formed in a material which undergoes a force tending to twist it

DeformationsElastic temporary change in

dimensions of a part when it put there under constraint. The object regains its shape as soon as the force is released

Plastic permanent deformation which occurs at the time of a setting under constraint and which remains when the force causing the deformation is removed

Mechanical Properties of Materials characteristic specific to a material. It

can determine the way in which the material will act or react under one or more mechanic pressures

Principle Mechanical Properties of Materials Property Definition

Hardness capacity to resist the deformation during the penetration of a hard body

Rigidity capacity to resist traction (tension)

Impact Strength capacity to resist shocks

Malleability capable of being flattened into thin sheets without tearing, under the effect of a compressive force such as hammering or rolling

Principle Mechanical Properties of Materials Property Definition

Brittleness fact of breaking without becoming deformed under the effect of a force

has little tendency to deform (or strain) before fracture

Ductility capacity to be able to be stretched into wire without breaking under the effect of a force of traction

Elasticity capacity of an object to regain its initial shape when the force which acts on it ceases

Principle Mechanical Properties of Materials Property Definition

Thermal Conductibility

capacity to transmit heat

Thermal Dilation Coefficient

property characterizing the relative increase in the volume of a body according to the increase in the temperature

Corrosion Resistance

capacity to resist the action of smoke, salts and chemicals which cause corrosion (rust)