§1.4 Unsymmetrical Bending 7 2a D Fig.1.5.Mohr's circle of second moments of area. The procedure is therefore identical to that for determining the direct stress on some plane inclined at a to the plane on which ox acts in Mohr's stress circle construction,i.e.angles are DOUBLED on Mohr's circle. 1.4.Land's circle of second moments of area An alternative graphical solution to the Mohr procedure has been developed by Land as follows (Fig.1.6): 0 Fig.1.6.Land's circle of second moments of area. (1)From O as origin of the given XY axes mark off lengths OA =I and AB =lyy on the vertical axis.$1.4 Unsymmetrical Bending YV 7 Fig. 1.5. Mohr's circle of second moments of area. The procedure is therefore identical to that for determining the direct stress on some plane inclined at CY to the plane on which uX acts in Mohr's stress circle construction, i.e. angles are DOUBLED on Mohr's circle. 1.4. Land's circle of second moments of area An alternative graphical solution to the Mohr procedure has been developed by Land as follows (Fig. 1.6): Y t V Fig. 1.6. Land's circle of second moments of area. (1) From 0 as origin of the given XY axes mark off lengths OA = I, and AB = I,, on the vertical axis