The state of stress at a point on an element is shown in figure (a). The same state of stress is shown in another coordinate system in figure (b).
The components (τxx, τyy, τxy) are given by
1
(p/√2, -p/√2, 0)
2
(0, 0, p)
3
(p, -p, p/√2)
4
(0, 0, p/√2)