What is Engineering Machanics ? |Deformable bodies.|Strength |Stiffness |Assumption in a som equation |

 Q. What is Engineering Machanics ?

Answer :- It is mechanics of rigid body.

​ If the relative position of the particles doesn't change even in the presence of external forces. then it is rigid body.

​ Study of external force & their effects.

MOS

​ It is mechanics of deformable bodies.

​ Here deals with the study of internal resistive forces.

​ Deformable bodies.

​Change in dimension/shape change.

​Resistance that has a tendency to oppose the change.

​ The basic objects of strength of materials to drive the expression for stresses, strans, deformation that are developed due to the external force, these are used in designing a component.

Strength :-

​ Ability of a material to resist failure against external forces.

​ The maximum stress that can be developed just before Failure is called strength.

​ It is material property and is const for a given material.

​ It is primary design parameter.

Stiffness :-

​Ability of a material to resist deformation.

​material property.

​second design parameter. 

Assumption in a som equation :-

​material should be solid and continious.

​No voids

​No cracks

Member should be homogeneous + Isotropic.

Homogeneous :-

​Material exhibit some elastic prop. In a given direction. 

​Material prop. Are independent of point.

Eg :- All base material without any mixture like wood, iron etc. 

Isotropic :-

​ Material exhibit same elastic prop. in all direction at a given point.

​It is independent of direction.

Eg :- All fine grained material like silver, brass, Cu etc. 

Orthotropic :-

​Ay one paint in three mutually parpandicullar direction material exhibit different elastic property.