Mohr's Circle Labeled

How this list was compiled: Every name checked on 2026-10-03 and kept only where two of these texts use it. (1) Wikipedia, text only, Mohr's circle: normal stress as the abscissa and shear stress as the ordinate; the two points plotted for the two perpendicular faces and the diameter drawn by joining them; the center where that line meets the normal stress axis, at the average normal stress; the radius; the principal stresses where the circle meets the normal stress axis; the maximum shear stress at the highest point, equal to the radius; the angle at the center as double the angle to the principal plane; the sign conventions for plotting shear. (2) David Roylance, Mechanics of Materials (a university course text published as an open textbook), section on transformations of stress: a graph with shear stress as the ordinate and normal stress as the abscissa; the x-face and y-face stresses plotted as two points labeled x and y and joined by a straight line; the circle drawn on that line as a diameter; the center at half the sum of the two normal stresses; the radius; the principal stresses, where shear is zero; the maximum shear stress, equal to the radius; the angle 2 theta to the principal planes; clockwise shear counted positive for the circle. (3) An online engineering formula reference, Mohr's circle for plane stress: the circle's center is the average stress and its radius equals the maximum shear stress. Licence: own work

The drawing: Drawn for this site on 2026-10-03 from plain geometry. The circle is computed from one made-up stress state; nothing is traced or copied. Licence: own work