Struct NeuberRule 

pub struct NeuberRule {
    pub kt: f64,
    pub e_modulus: f64,
    pub k_prime: f64,
    pub n_prime: f64,
}

Neuber’s rule for notch analysis.

Neuber’s rule relates the theoretical (elastic) stress/strain at a notch to the actual local elastic-plastic stress and strain:

(Kt * σ_nom)² / E = σ_local * ε_local

i.e., the geometric mean of local stress and strain energy equals the nominal elastic value scaled by Kt².

Given nominal stress σ_nom, stress concentration factor Kt, and Young’s modulus E, the Neuber hyperbola is: σ_local * ε_local = (Kt * σ_nom)² / E

When combined with a cyclic stress-strain curve (e.g., Ramberg-Osgood) the intersection gives the actual local stress and strain.

Fields

kt: f64

Stress concentration factor Kt.

e_modulus: f64

Young’s modulus E (Pa).

k_prime: f64

Ramberg-Osgood cyclic strength coefficient K’ (Pa).

n_prime: f64

Ramberg-Osgood cyclic strain hardening exponent n’.

Implementations

impl NeuberRule

pub fn new(kt: f64, e_modulus: f64, k_prime: f64, n_prime: f64) -> Self

Create a new Neuber rule model.

pub fn neuber_product(&self, sigma_nom: f64) -> f64

Neuber hyperbola product: (Kt * σ_nom)² / E

pub fn ramberg_osgood_strain(&self, sigma_local: f64) -> f64

Ramberg-Osgood total strain for a given local stress.

ε = σ/E + (σ/K’)^(1/n’)

pub fn local_stress(&self, sigma_nom: f64, max_iter: usize) -> f64

Solve for local stress using Neuber’s rule + Ramberg-Osgood (bisection).

Finds σ_local such that σ_local * ε(σ_local) = (Kt * σ_nom)² / E.

pub fn local_strain(&self, sigma_local: f64) -> f64

Solve for local strain from local stress (direct Ramberg-Osgood).

pub fn cyclic_local_stress_strain( &self, sigma_nom_amp: f64, max_iter: usize, ) -> (f64, f64)

Cyclic Neuber analysis: compute local stress and strain amplitudes for a given nominal stress amplitude using Masing’s hypothesis.

For cyclic loading, the cyclic Ramberg-Osgood uses factor 2: Δε = Δσ/E + 2*(Δσ/2K’)^(1/n’)

Returns (sigma_a_local, epsilon_a_local).

Trait Implementations

impl Clone for NeuberRule

fn clone(&self) -> NeuberRule

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for NeuberRule

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

Formats the value using the given formatter.