In a Machine, every component subjected to various forces. Due to these forces acting on the machine components, there are various types of stresses are induced. Where a simple stress is defined as the internal resistance force that opposes the external force per unit area. Where the Strain is defined as the deformation per unit length. All these simple stress and strain are briefly described below.
A simple Stress and strain are produced due to any of the following type of actions done on the machine parts. they are
- Self-weight of the machine
- Energy Transmitted
- Change of temperature
- Frictional resistance
- The inertia of reciprocating parts
- Unbalance of Moving parts.
These actions cause a different variety of stresses.
- Tensile Stresses
- Compressive Stresses
- Shear Stresses
- Bending Stresses
- Torsion Stresses
Simple Stress and Strain
Consider a force is acting on a body on a unit area. a simple stress is defined as the internal force which is resisting the external force per unit area. It is denoted with σ
Stress (σ )= F/A
F = Force acting on the body
A = Cross-sectional Area where the force is acting
Due to the external forces, the body may undergo some deformation. This deformation per unit length is said as the Strain. Strain represented by ε
Strain (ε) = δl/l
δl = Change in the length of the body
l = Original length of the body
Now let’s see the different type of stresses one by one.
When a body subjected to two equal and opposite axial pulling forces(Tensile Load) then the stress produced in every section of the body is called Tensile stresses.
Tensile strain Is the change in length by its original length.
When a body subjected to two equal and opposite axial pushing forces(Compression Load) then the stress produced in every section of the body is called Compressive stresses.
Compressive strain Is the change in length by its original length.
Consider a Revit has joined two metal sheets together. Then the two sheets subjected to two equal and opposite forces acting tangentially across the Revit section. Then the stress induced in the Revit is called Shear stresses. See it on the side fig.
Bending stress is usually occur in longitudinal objects. When forces acting on a longitudinal object then the objects tend to bend. The stresses induced due to bending is known as the bending stresses.
A twisting force acting on an object causes the torsional stresses. Example A bolt is tightening with the help of a wrench the bolt is subjected to twisting force and some torsional stresses will be induced in the bolt due to twisting force.
These are the different type of stresses and strains. and there is a different type of stresses are there they are Normal stress and volumetric stresses are also available.