Coupled bend–twist mechanics of biomimetic scale substrate

We develop the mechanics of combined bending and twisting deformation a one-dimensional filamentous structure with protruding stiff fish-scale-like plates embedded at an angle on surface. Cosserat kinematic formulation along scale contact constraints. This geometrically exact model allows us to bypass limitations small deflection finite element computations, thereby preserving accuracy kinematics. The derived structure–property relationships reveal, for first time, effect slender fish-scale inspired substrate. subsumes previous models pure twisting, but also shows previously unobserved phenomena that arise due coupled effects these loads. These include new interpretation locking behavior, multiple regimes, asymmetric sensitivities one curvature over other, discontinuous transitions in nonlinear moment–curvature torque–twist behaviors, reflecting complex engagement patterns.