Struct FiberSection3 

pub struct FiberSection3 { /* private fields */ }

Biaxial fiber-discretized cross-section: given axial strain eps0, curvature about local z kappa_z (bending that displaces local y, the plane FiberSection/ElasticBeamColumn3’s Iz governs), and curvature about local y kappa_y (displaces local z, Iy’s plane), each fiber’s strain is eps0 - y*kappa_z + z*kappa_y — the natural biaxial extension of FiberSection’s eps0 - y*kappa, verified against Xara’s FiberSection3d::addFiber/getStressResultant (matData/sData layout: strain = e0 - y*e1 + z*e2, N = sum(stress*A), Mz = sum(-y*stress*A), My = sum(z*stress*A)) rather than re-derived from scratch.

Work-conjugate to [eps0, kappa_z, kappa_y] is [N, Mz, My], and the tangent’s off-diagonal terms follow directly from differentiating those three sums (see FiberSection3::trial’s body) — independently reproducing Xara’s kData layout (kData[1]=-y*EA summed → -EQz, kData[2]=z*EA summed → EQy, kData[6]=-y*z*EA summed → -EIyz) gives useful cross-confirmation that the sign convention here matches the reference exactly, not just plausibly.

Implementations

impl FiberSection3

pub fn new(fibers: Vec<Fiber3>) -> Self

pub fn trial( &self, eps0: f64, kappa_z: f64, kappa_y: f64, ) -> (f64, f64, f64, [[f64; 3]; 3])

Trial evaluation at (eps0, kappa_z, kappa_y) — read-only, safe every Newton iteration (see FiberSection::trial’s doc comment for why).

pub fn commit(&mut self, eps0: f64, kappa_z: f64, kappa_y: f64)

Commit every fiber’s material at (eps0, kappa_z, kappa_y) — called once per converged step.

pub fn total_area(&self) -> f64

pub fn fiber_responses( &self, eps0: f64, kappa_z: f64, kappa_y: f64, ) -> Vec<(f64, f64)>

See FiberSection::fiber_responses’s doc comment — same contract, biaxial strain field.

Trait Implementations

impl Clone for FiberSection3

fn clone(&self) -> FiberSection3

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FiberSection3

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

Formats the value using the given formatter.