In prior examinations we have gone through an essential course in mechanics of Rigid Bodies, all the more regularly alluded to as Engineering Mechanics or Applied Mechanics. Mechanics as such is partitioned into three branches; Mechanics of Rigid bodies, Mechanics of Deformable Bodies and Mechanics of liquids.
Mechanics of Rigid Bodies expected bodies to be totally unbending for example there is no misshapening of bodies under the activity of burdens to which they are oppressed statics and Dynamics are the two parts of Mechanics Of inflexible Bodies including fixed and moving bodies separately under the activity of burdens.
Stress:-
I. The power of protections per unit are offered by a body against twisting is known as Stress. At the point when a body is exposed to outer stacking the body goes through some misshapening. Simultaneously interior power of opposition is because of the union of particles inside the body. Consequently stress is instigated in the body upon outside activity of burden
ii. On the off chance that the body can oppose the outside burden, it is supposed to be steady, in balance and accordingly for this condition the inner power of opposition ought to be equivalent to the outer burden.
By Definition Stress=force of obstruction/cross sectional territory
Or on the other hand Stress=P/A
Strain:-
As the body produce power of protection from counter the outside stacking it goes through some disfigurement. The degree of distortion rely upon the material property like atomic union. The proportion of progress in measurement is known as strain.
Since Strain is proportion, it has no units. We will signify strain by letter e. On the off chance that L is the first measurement and is change in measurement and, at that point
Strain =Change in measurement/Original measurement
Kinds of Stress:-
1) Direct Stress and Direct Strain:-
At the point when the power of opposition acts ordinary or opposite to the territory on which it acts, the pressure so delivered is named as Direct or Normal Stress and comparing strain is alluded to as Direct Strain.
We will indicate direct worry by letter 'f'. Direct pressure could be of elastic nature of compressive nature.
2) Tensile pressure:-
At the point when the power of obstruction acts from the cross sectional zone, the immediate pressure is of ductile nature. Malleable burdens will in general reason an expansion in the first measurement.
3) Compressive Stress:-
At the point when the power of obstruction acts towards the cross sectional territory, the immediate pressure is of compressive in nature. Compressive burdens will in general reason a lessening in the first measurement.
