Lecture 5

[senabh...@gmail.com]

Can anyone explain/clarify the equation of rotational strain i.e Theta prime - theta = 1/2 ( delta alpha + delta beta ) .

I mean why 1/2 ???

Regards

[Omkar Manav]

if you could recollect that the rotational angle was considered allong the diagonals and the shear angles along the edges of the element (square) and  due to approximation and angle being small and the element on which the  analysied the rotational and shear deformation was a square .   we transformed the edge and diagonal to equal magnitude (same radians) in anticlockwise and to bring in equilibrium the clockwise transformation of same magnitude was considered  

the  difference in the angle of rotation which consider( theta prime-theta is for diagonal) and the diference (alpha-beta) is for edge the change in the angles due to the symmetry of square comes to be half diagonal (teta is the diagonal angle and tetha prime is the angle when the diagonal was rotated  in anticlockwise  )