Struct DelamCriterion 

pub struct DelamCriterion {
    pub z_t: f64,
    pub s_xz: f64,
    pub s_yz: f64,
    pub g1c: f64,
    pub g2c: f64,
    pub g3c: f64,
    pub bk_eta: f64,
}

Delamination fracture criterion for composite laminates.

Implements:

1. Quadratic stress criterion (interlaminar stresses).
2. Linear fracture mechanics criterion (G vs G_c).
3. Benzeggagh-Kenane (B-K) mixed-mode criterion.

Fields

z_t: f64

Interlaminar tensile strength Z_t (Pa).

s_xz: f64

Interlaminar shear strength S_xz (Pa).

s_yz: f64

Interlaminar shear strength S_yz (Pa).

g1c: f64

Mode I critical ERR G_Ic (J/m²).

g2c: f64

Mode II critical ERR G_IIc (J/m²).

g3c: f64

Mode III critical ERR G_IIIc (J/m²).

bk_eta: f64

Benzeggagh-Kenane exponent η (C/E: ≈ 1.75).

Implementations

impl DelamCriterion

pub fn new( z_t: f64, s_xz: f64, s_yz: f64, g1c: f64, g2c: f64, g3c: f64, bk_eta: f64, ) -> Self

Constructs a DelamCriterion.

pub fn carbon_epoxy_default() -> Self

Returns default values for carbon/epoxy (T300/914).

pub fn quadratic_stress_index(&self, stress: InterlaminaStress) -> f64

Computes the quadratic interlaminar stress criterion.

(⟨σ_z⟩/Z_t)² + (τ_xz/S_xz)² + (τ_yz/S_yz)² ≥ 1 → delamination

where ⟨·⟩ is the Macaulay bracket (only tensile σ_z contributes).

pub fn stress_delamination(&self, stress: InterlaminaStress) -> bool

Returns true if the quadratic stress criterion is violated.

pub fn linear_err_index(&self, err: EnergyReleaseRate) -> f64

Computes the linear ERR criterion.

G_I/G_Ic + G_II/G_IIc + G_III/G_IIIc ≥ 1 → delamination

pub fn err_delamination(&self, err: EnergyReleaseRate) -> bool

Returns true if the linear ERR criterion is violated.

pub fn bk_criterion(&self, err: EnergyReleaseRate) -> f64

Computes the mixed-mode B-K criterion (Benzeggagh–Kenane 1996).

G_Ic + (G_IIc − G_Ic) * (G_shear/G_total)^η = G_c(mm) Delamination when G_total ≥ G_c(mm).

pub fn bk_delamination(&self, err: EnergyReleaseRate) -> bool

Returns true if B-K criterion is violated.

pub fn stress_intensity_mode1(&self, sigma_z: f64, half_crack: f64) -> f64

Computes the mode I stress intensity factor K_I from σ_z and half-crack a (m).

K_I = σ_z √(π a)

pub fn g1c_from_k1c(k1c: f64, ez: f64) -> f64

Returns the critical G_I from mode I fracture toughness K_Ic using G = K²/E.

G_Ic = K_Ic² / E_z where E_z is the through-thickness modulus (Pa).

pub fn j_integral_proxy(&self, err: EnergyReleaseRate) -> f64

Computes the crack driving force (J-integral proxy) from ERR (J/m²).

pub fn paris_growth_rate( &self, delta_g1: f64, delta_g2: f64, paris_c: f64, paris_m: f64, ) -> f64

Estimates the delamination growth rate da/dN (m/cycle) using a Paris law.

da/dN = C (ΔG_equiv)^m

where ΔG_equiv = ΔG_I + ΔG_II * (G_IIc/G_Ic)^α (approximate).

Trait Implementations

impl Clone for DelamCriterion

fn clone(&self) -> DelamCriterion

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DelamCriterion

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

Formats the value using the given formatter.