For a circular cross section, we know that the shear stress due to a shear force at the boundary (the radius of the circle) has to be tangent to the curvature. This is so that we have no radial shear stress. However, I was wondering how could we calculate the direction of the resultant shear stress vectors at any point (x, y). Either as an angle or a normal vector. Is there a formula for this? I tried searching for it but was unable to find it.
Also, what would the magnitude of the resultant shear vector be? Would it still be the value of the shear stress formula:
or does this formula only work for the vectors along the vertical axis?
Any help is appreciated.
