Dynamic Mechanical Damping and Viscoelastic Energy Dissipation in Vat-Printed Photopolymers: Frequency, Temperature, Cure State, Architecture and Qualification

Vat-photopolymerised thermosets are frequently described using static tensile modulus, Shore hardness, elongation or impact strength, yet vibration control and dynamic energy dissipation require a different measurement architecture. In linear viscoelastic response, an oscillatory strain produces a phase-shifted stress that can be decomposed into storage and loss components; the ratio of loss to storage response is commonly expressed as tan delta. Primary DLP research demonstrates that the dynamic mechanical response of printed photopolymers depends on temperature, loading frequency and degree of cure, while recent VPP-specific methodological work shows that specimen preparation, linear-viscoelastic-region determination, residual stress and print protocol can materially affect intercomparison. Composite studies further show effects of filler loading, alignment, post-print thermal treatment and semicrystalline morphology. This Engineering Review develops a state-aware qualification architecture for dynamic damping in VPP. It separates DMA material loss from structural damping, cyclic hysteresis and high-strain-rate energy absorption; defines frequency, temperature, amplitude, deformation mode, cure state, orientation and architecture as mandatory reporting variables; and positions time-temperature superposition as a conditional extrapolation tool rather than a universal prediction method. ISO 6721-1:2019, ISO 6721-4:2019, ISO 6721-12:2022 and ASTM D4065-20 are used as current method anchors. 3Dresyns elastomeric and damping-oriented products are included only as manufacturer implementation examples; no tan delta, damping coefficient, resonance attenuation or service-life claim is inferred from commercial positioning.