Propellant and other viscoelastic materials respond across broad time scales, and their constitutive behavior can evolve with operating conditions. A compact standard Prony model may not reproduce that changing response with sufficient fidelity.
Solid rocket motor response
Capture broadband, history-dependent material response with a compact fractional-hybrid model.

The challenge and the Phractals approach.
Phractals combines fractional and classical model elements to represent long material memory without requiring a large expansion of discrete relaxation branches. The comparison keeps the numerical reference, hybrid prediction, and integer-order baseline visible together.
The animation compares ground-truth displacement with a fractional-hybrid model and a standard integer-order Prony model using the same parameter count, while the lower panels expose normalized error across the motor section.
Fractional-hybrid versus Prony response
Ground truth, fractional-hybrid, and integer-order Prony displacement fields are paired with their normalized errors.
RMS material-fit error comparison
The hybrid formulation preserves the material-fit reference while requiring far fewer model parameters and reducing the RMS error compared with the equivalent Prony baseline.
Why this application matters.
Represent broadband creep, relaxation, and damping with compact models.
Expose where a conventional constitutive baseline diverges from the numerical reference.
Improve confidence in simulations that depend on long loading and operating histories.

Reduced-order thermal conduction
Retain thermal-memory effects and microscale behavior without resolving every feature in the production model.
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Biomaterial dynamics
Study transient deformation in compliant, heterogeneous materials where damping and history shape the response.
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Coupled thermo-mechanics
Couple temperature and deformation in a two-way workflow without building a custom coupling chain.
Explore the caseBring us your data and modeling challenges.
We will identify whether this Phractals workflow fits your engineering decision.