Auxetic Photopolymer Structures: Geometry, Manufacturing Defects, Strain Range and Failure

Auxetic response is a geometric mechanism that can be lost through small changes in hinge thickness, re-entrant angle, node shape or material nonlinearity. ER-362 focuses on the conditions under which a negative Poisson response remains measurable, repeatable and structurally useful after photopolymer manufacture. Full-field strain measurements are coupled to as-built geometry and local damage inspection so that kinematic rotation can be distinguished from hinge bending, fracture or out-of-plane buckling. Strain-range, orientation and defect perturbations establish the usable auxetic window. Qualification therefore requires not only a negative Poisson ratio, but retention of the intended deformation mode and an explicit limit on damage accumulation and manufacturing sensitivity.

ER-362.