Determine analytically the transformed state of stress on an
Solution
solution:
1) here if given point is rotated by a=-40 cw then stresses in element is given by
sx\'=sx+sy/2+(sx-sy/2)cos2a+txysin2a=120+80/2+40/2cos80-40sin80=64.08 mpa
sy\'=sx+sy/2-(sx-sy/2)cos2a-txysin2a=135.91 mpa
txy\'=-(sx-sy/2)sin2a+txycos2a=26.64 mpa
2) here principle stresses in rotated plane is given by
s1,2sx+sy/2+-((sx-sy/2)^2+txy^2)^.5
on putting value we get
s1=144.72 mpa
s2=55.28 mpa
where principle stress same for any position for same element
principle plane angle=tan2*ap=2txy\'/sx\'-sy\'=2*26.64/64.08-135.91
ap=-36.56 degree and it is vary with position
4) maximum shear stress is
txymax=((sx-sy/2)^2+txy^2)^.5=44.72 mpa
priciple shear plane angle=tan2*as=-(sx\'-sy\'/2txy\')
as=8.44 degree
where as=ap(+-)45
5) this result can be evaluated over mohr cicle of radius
r=s1-s2/2
and plotting all value over s abd txy axis
