( x , y , z ) or

right hand tria 
Displacement (u , v , w ) or
Stress = Linear
, stress vector (force / area)
T Stress vector = Force / Area with outward drawn normal
Similarly for other plane
Infinite plane exist at a point P
Infinite vectors
Plane/ Area is defined by outward drawn normal.
Infinite planes
3 – mutually outward drawn planes at point P

(x1, x2 , x3,)
Planes
at P

Stress
vector


State of stress at
a point 
State of stress at a point =
Body is continuous and remain continuous under
the action of external forces 

(H1) Elastic Continuum Neighbor remain neighbor
under external force No cracks /gaps or voids
(H2) There exists a unique unstressed state of the solid body
to which the body returns whenever all the external forces
are removed.
(H3) Principle of super position holds good


