Mechanical Properties of Materials

Mechanical properties help us measure how materials behave under a load. The mechanical properties of materials are mentioned below.

Elastic Material:

Elastic stress is a material that regains its original size and shape after removing stress.

Plastic material:

Plastic material can undergo permanent deformation without rupture. This property is known as plasticity. Plasticity is essential when a material is mechanically formed, causing it to flow.

Ductile Material:

A material that undergoes considerable deformation without rupture is considered ductile. The central portion of the deformation is plastic.

Brittle Material:

A material that ruptures with little or no plastic deformation is said to be a brittle material.

Also read: Mechanical Properties of a Metal

Set of Permanent set:

The deformation or strain remaining in a body after removing stress is known as a permanent set. This is due to the elastic property of the material.

Elastic limit:

The most significant stress that a material can take without a permanent set of removing stress is known as an elastic limit.

Proportionality limit:

The proportionality limit is the most significant stress a material can take without deviation from a straight line between stress and strain.

Endurance limit or Fatigue limit:

The most significant stress applied an infinite number of times that a material can take without causing failure is known as the endurance limit or fatigue limit.

Ultimate Strength:

The maximum stress a material can withstand is known as its ultimate strength. Ultimate strength equals the maximum load divided by the original area of the cross-section.

Modulus of Resilience:

The energy stored per unit volume at the elastic limit is known as the modulus of resilience.

Modulus of Toughness:

The modulus of toughness is the amount of work required per unit volume to cause failure under static loading.

Modulus of Rupture:

The ultimate strength in flexure or torsion is known as the modulus of rupture.

Strain hardening:

The increase in strength after the plastic zone is due to the rearrangement of molecules in the material.

Proof stress:

The stress is sufficient to cause a permanent set(elongation) equal to a specified percentage of the original gauge length.

Elastic Strain:

Elastic strain is a dimensional change that occurs in a material when loads are applied and disappear entirely when the loads are removed.

Plastic Strain:

It is a dimensional change that occurs in a material due to the application of loads and does not disappear after the loads are removed.

Ductility and malleability:

The plastic response of material to tensile force is known as ductility, and the plastic response to compression force is known as malleability. The elongation and reduction of the area of the test piece tested to failure in tension are generally taken as measures of the material's ductility.

Creep:

The long-term deflection is due to sustained (constant) loads.

The factor of SafetySafetyctor of safetySafetyfined as follows

For Ductile materials,

F.O.S = yield stress/working stress

For Brittle materials,

F.O.S = ultimate stress/working stress

The margin of Safety:

Margin of safety = Factor of safety – 1