To determine the state of stress at $D$ in the cantilever beam, we will need to do several things:

1. Draw the shear-force and bending-moment diagrams for the cantilever. From these diagrams, we will determine the internal shear force $V$ and the internal bending moment $M$ acting at the point of interest.

2. Determine the section properties for the tee shape. Since the shape is not symmetric about a horizontal axis, we must first determine the location of the centroid. Then, we will compute the moment of inertia and $Q$.