Stress and strain definition and formua, stress and strain curve, list of Mechanical property of materials, Mechanical properties of engineering materials, Learn with Ashiso, learnwithashiso.

 Solid:-

              Substances having definite shape, size and also resist any kind of deformation is known as solid body. 

Types of solid body:-

i. Rigid body

ii. Deformable body

1. Rigid body:-

                             Body is considered rigid when by applying forces, changes in distance between the two point ( within the body ) is negligible that is body dies not deform on application of external forces. 

                 Eg:- Brick, Glass. 

2. Deformable body:-

                                         If there is change in distance between two points on applying load, then the body is considered as deformable body. 

        Eg:- Steel, Iron. 

Note:-

• When a body is rigid, it means strain in the body is zero. 
• In MOS , we only deal with the application of deformable body. 

☆ Force, Stress & Strain

Force:-

             Push or pull is termed as force. 

Stress:-

              Force of resistance offered by a body against any load. 

         

           Stress = Force/ Area 

           Unit = N/ m^2.

Strain:-

              It is defined as per unit deformation due to stress developed. 

                   Strain = dL/L.

It is unit less.

Mechanical Properties of solid materials:-

Strength:-

It is defined as the maximum value if stress that a material can withstand without any failure.

Note:-

• It doesn't depend on shape and size of the material. 
• It is constant for any particular material. 

Stiffness / Rigidity:-

                                  The extent to which a material is able to the resist deformation under the applied load is termed as stiffness or rigidity of materials. 

Toughness:-

                      It is the resistance against sudden load or impact load or shock load ( hammer blow) is termed as toughness. 

Ductility:-

                   It is the ability of material to convert into wire without showing any sign of failure/ Rupture in application of tensile forces. 

Malleability:-

                           It is the ability of a material to convert into sheet on bearing with a hammer or roller. 

Note:-

           Generally ductile material is also malleable, with very few exception like lead ( Pb ), which is malleable but it is not ductile. 

Brittleness:-

                        The lack of ductility and malleability in a material that is it suddenly get fractured without sufficient warning or remarkable sign of deformation under the action of applied load is known as brittleness. 

Hardness:-

                     It is the ability of a material to resist against abrasion, scratching, wear and tear. 

Fatigue:-

                  The phenomenon that leads to fracture in any substance due to cyclic or repeated or alienating loads, failure due to this phenomenon is termed as fatigue failure. 

Endurance limit:-

                                  It is the stress level below which a metal has very less chance to have fatigue failure even at infinite no of cycles.

Creep:-

               It is permanent deformation ( plastic deformation) which may occur with the passage of time under constant loading.

Elasticity:-

                  Any materials having ability to regain its original shape just after the removal of the applied load is considered as elastic material and this property is known as elasticity. 

Plasticity:-

                    Material which is not elastic is plastic that is any material which has not the ability to regain its original shape and size is plastic material. So we can say that plasticity is a permanent deformed shape or size. 

      

                  Thanks for reading.