Struct BrinsonModel 

pub struct BrinsonModel {
    pub temps: TransformationTemperatures,
    pub cm: f64,
    pub ca: f64,
    pub h_max: f64,
    pub e_a: f64,
    pub e_m: f64,
    pub theta: f64,
    pub sigma_crit_s: f64,
    pub sigma_crit_f: f64,
}

Brinson model for SMA — separates stress-induced (ξ_S) and temperature-induced (ξ_T) martensite fractions.

The total martensite fraction is ξ = ξ_S + ξ_T, where each component follows cosine kinetics with separate evolution rules. This allows capturing both superelasticity and shape memory effect within a single unified framework.

Fields

temps: TransformationTemperatures

Transformation temperatures.

cm: f64

Clausius-Clapeyron slope for martensite (Pa / K).

ca: f64

Clausius-Clapeyron slope for austenite (Pa / K).

h_max: f64

Maximum transformation strain ε_L.

e_a: f64

Austenite elastic modulus (Pa).

e_m: f64

Martensite elastic modulus (Pa).

theta: f64

Thermoelastic tensor Θ (Pa / K).

sigma_crit_s: f64

Critical start stress for detwinning at T < Ms (Pa).

sigma_crit_f: f64

Critical finish stress for detwinning at T < Ms (Pa).

Implementations

impl BrinsonModel

pub fn new( temps: TransformationTemperatures, cm: f64, ca: f64, h_max: f64, e_a: f64, e_m: f64, theta: f64, sigma_crit_s: f64, sigma_crit_f: f64, ) -> Self

Create a new Brinson model.

pub fn effective_modulus(&self, xi: f64) -> f64

Effective elastic modulus via the rule of mixtures.

pub fn critical_stresses_at_temp(&self, temp: f64) -> (f64, f64)

Phase diagram critical stress at temperature T (stress-induced).

Returns (sigma_ms, sigma_mf) — the start and finish stresses for stress-induced martensitic transformation at temperature T.

pub fn xi_s_loading( &self, temp: f64, stress: f64, xi_s_prev: f64, _xi_t_prev: f64, ) -> f64

Compute stress-induced martensite fraction ξ_S for the loading branch.

Uses cosine kinetics between sigma_crit_s and sigma_crit_f shifted by temperature.

pub fn xi_t_cooling(&self, temp: f64, stress: f64, xi_t_prev: f64) -> f64

Compute temperature-induced martensite fraction ξ_T for cooling.

pub fn reverse_fractions( &self, temp: f64, stress: f64, xi_s_prev: f64, xi_t_prev: f64, ) -> (f64, f64)

Reverse transformation (M → A): both ξ_S and ξ_T decrease.

pub fn stress_response( &self, strain: f64, xi_s: f64, xi_t: f64, temp: f64, temp_ref: f64, ) -> f64

Integrated constitutive relation: σ = E(ξ)(ε − ε_L ξ_S) + Θ(T − T₀).

pub fn update_state( &self, state: &mut SmaPhaseState, strain_new: f64, temp_new: f64, )

Incremental update for a full Brinson loading step.

Trait Implementations

impl Clone for BrinsonModel

fn clone(&self) -> BrinsonModel

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for BrinsonModel

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.