Struct BoneModel 

pub struct BoneModel {
    pub density: f64,
    pub mineral_fraction: f64,
    pub e_axial: f64,
    pub e_transverse: f64,
    pub shear_modulus: f64,
    pub trabecular_thickness: f64,
    pub trabecular_length: f64,
}

Bone tissue constitutive model (cortical + cancellous).

Implements:

• Transversely isotropic elasticity for cortical bone.
• Gibson-Ashby cellular foam model for trabecular bone.
• Kopperdahl-Keaveny mineral-density to modulus correlation.
• Simplified Wolff’s law density adaptation.

Fields

density: f64

Apparent density ρ [g/cm³] (0.1–2.0 for cancellous, ~1.9 for cortical).

mineral_fraction: f64

Mineral volume fraction (ash fraction) [0..1].

e_axial: f64

Axial Young’s modulus E_axial [GPa] (cortical, along osteons).

e_transverse: f64

Transverse Young’s modulus E_transverse [GPa] (cortical).

shear_modulus: f64

Shear modulus G [GPa] (cortical).

trabecular_thickness: f64

Trabecular thickness t_b [mm].

trabecular_length: f64

Trabecular length l_b [mm].

Implementations

impl BoneModel

pub fn new( density: f64, mineral_fraction: f64, e_axial: f64, e_transverse: f64, shear_modulus: f64, ) -> Self

Construct a BoneModel with explicit mechanical properties.

pub fn density_to_modulus_kk(density: f64) -> f64

Kopperdahl-Keaveny correlation: density [g/cm³] → Young’s modulus [MPa].

E = 6850 * ρ^1.49 for apparent density in g/cm³ (trabecular bone).

pub fn gibson_ashby_modulus(&self, solid_modulus_gpa: f64) -> f64

Gibson-Ashby foam model: relative density → relative Young’s modulus.

E/E_s = C * (ρ/ρ_s)^2 where C ≈ 1.0, ρ_s = solid bone density (~1.9 g/cm³).

pub fn trabecular_modulus(&self) -> f64

Compute trabecular bone apparent modulus using Gibson-Ashby.

Returns modulus in GPa.

pub fn wolff_adapt( &mut self, sigma_actual: f64, sigma_ref: f64, k: f64, s: f64, dt: f64, )

Apply Wolff’s law density adaptation.

Updates the apparent density based on the daily stress stimulus σ_ref compared to the homeostatic stimulus σ_ref.

dρ/dt = k * (σ_actual - σ_ref) with lazy zone ±s.

pub fn yield_strength(&self) -> f64

Compute bone yield strength [MPa] from mineral fraction (Currey).

σ_y = 94.0 * mineral_fraction^3.84

Trait Implementations

impl Clone for BoneModel

fn clone(&self) -> BoneModel

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for BoneModel

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

Formats the value using the given formatter.