Stress concentration patterns in the mineral layer 2 as a function of the stiffness ratio of the collagen phase vs. the mineral phase (G/Em) For a more compliant collagen phase (G/Em = 0.01), the stress concentration region is significantly expanded compared with a stiffer collagen phase (G/Em = 0.1) For ease of analysis, the following material and spatial properties of the mineral and collagen phases are employed: Em = 100 GPa, n = 3, h/d = 1.0, where G is the shear stiffness of the collagen phase, Em is the elastic modulus of the mineral phase, n is the collagen non-linearity factor, h and d are the thickness of the collagen and mineral phases, respectively.