Struct CdmDamage 

pub struct CdmDamage {
    pub d: f64,
    pub eps0: f64,
    pub eps_f: f64,
    pub param: f64,
    pub law: DamageEvolutionLaw,
    pub kappa: f64,
}

General CDM model with selectable damage evolution law.

Tracks a scalar damage variable D that degrades effective stress and stiffness according to the principle of strain equivalence.

Fields

d: f64

Current damage variable D ∈ [0, 1].

eps0: f64

Damage initiation strain ε_0.

eps_f: f64

Failure strain ε_f (used in linear and power-law).

param: f64

Evolution rate parameter (exponential: a, power-law: n).

law: DamageEvolutionLaw

The damage evolution law to use.

kappa: f64

Maximum historical equivalent strain (for irreversibility).

Implementations

impl CdmDamage

pub fn new(eps0: f64, eps_f: f64, param: f64, law: DamageEvolutionLaw) -> Self

Create a new CDM damage model.

Arguments

• eps0 - Damage initiation strain
• eps_f - Failure strain (for Linear/PowerLaw)
• param - Rate parameter (exponential: a, power-law exponent: n)
• law - Which evolution law to use

pub fn update(&mut self, equivalent_strain: f64)

Update damage based on current equivalent strain.

Damage only increases (irreversibility via internal variable κ).

pub fn effective_stiffness(&self, young_modulus: f64) -> f64

Effective stiffness: E_eff = (1 - D) * E.

pub fn effective_stress(&self, nominal_stress: f64) -> f64

Effective stress: σ_eff = σ / (1 - D).

pub fn compute_localization_indicator( &self, young_modulus: f64, poisson_ratio: f64, ) -> f64

Compute the strain localization indicator based on acoustic tensor analysis.

In continuum damage mechanics, strain localization (shear band initiation) occurs when the acoustic tensor Q(n) becomes singular. The indicator is:

L = D * E / ((1-D)² * (1 - 2ν) * (1 + ν) / (3*(1-ν)))

or more precisely the determinant-like measure derived from the damaged tangent modulus. Here we use a practical scalar indicator:

L = D / ((1-D)² + ε_reg)

scaled by the ratio of shear to bulk modulus terms for 3D isotropy.

Arguments

• young_modulus - Undamaged Young’s modulus E [Pa]
• poisson_ratio - Poisson’s ratio ν (0 ≤ ν < 0.5)

Returns

Localization indicator L (dimensionless, positive; → ∞ near full damage)

Trait Implementations

impl Clone for CdmDamage

fn clone(&self) -> CdmDamage

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for CdmDamage

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

Formats the value using the given formatter.