I tried to plot the shear stress of a cantilever beam, which is loaded at one free end by a downward force (-y direction). Then I tried to plot the shear stress of the left half of the beam, and found that the shear stress (sigma_xy) in the whole left half is negative.
Then I tried to plot the shear stress of the right half of the beam, I found that all the shear stress in the whole right half is negative too.
My question: From the free body diagram of the left half, the force applied by the right half to the left half at the cut-section should be downward (-y), and the force applied by the left half to the righ half, at the cut-section, should be positive. HOw comes both shear stress plotting, for both left and right halves, have all negative shear stress values?
I may have missed something. But can somebody explain a little, Or if you know how to interpret ANSYS' shear stress plot?
Thanks a lot in advance,