Impact and High-Rate Response of Printed Photopolymers: Strain Rate, Temperature, Specimen Geometry and Failure Mode

Impact resistance and high-rate response are not single properties of a printed photopolymer. Pendulum impact energy, drop-weight force history, rapid servo-hydraulic stress–strain response and split-Hopkinson measurements interrogate different geometries, rate histories and failure processes. Their results depend on resin chemistry, print orientation, exposure, wash, post-cure, conditioning, specimen dimensions, notch state, temperature, stress state and data-reduction assumptions. A higher response at rapid loading does not establish a universal dynamic increase factor, and absorbed impact energy is not interchangeable with a constitutive law. This review defines a non-compensatory qualification framework for printed photopolymers under impact and rapid loading. It requires the loading device and specimen rate history to be identified, separates apparatus response from specimen response, and treats dynamic equilibrium, wave dispersion, pulse shaping, inertia and adiabatic heating as validity questions rather than reporting details. Rate and temperature are coupled, while build and cure state can change both failure stress and morphology. Constitutive calibration must be separated from prediction and validated at an additional rate or temperature. The primary corpus supports this state-resolved approach but does not establish universal impact strengths, strain-rate exponents, failure thresholds or transferable crashworthiness values.