Struct FiberSection 

pub struct FiberSection { /* private fields */ }

A fiber-discretized cross-section: given the section’s axial strain eps0 (at the centroid) and curvature kappa, each fiber’s strain is eps0 - y*kappa. Work-conjugate to [eps0, kappa] is [N, M] (N = sum(stress*area), M = -sum(stress*area*y)) — derived directly from virtual work, not assumed: d(stress power) = integral(stress * d(strain)) dA = integral(stress*(d(eps0) - y*d(kappa))) dA = d(eps0)*N + d(kappa)*M with M as defined above.

Each DispBeamColumn integration point owns its own FiberSection (independent material history — see Element’s commit/trial split), even when every point starts from an identical fiber layout (the prismatic-member assumption this element makes: same cross-section everywhere along the length — a tapered/non-prismatic member is a natural extension, not built until needed).

Implementations

impl FiberSection

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

pub fn trial(&self, eps0: f64, kappa: f64) -> (f64, f64, [[f64; 2]; 2])

Trial evaluation at (eps0, kappa) — read-only, safe every Newton iteration; see Material’s doc comment for why this must not mutate any fiber’s material.

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

Commit every fiber’s material at (eps0, kappa) — called once per converged step, by DispBeamColumn::commit.

pub fn total_area(&self) -> f64

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

Every fiber’s (strain, stress) at (eps0, kappa), in the same order fibers were originally passed to new — the same evaluation trial sums into (N, M), broken out per fiber instead of aggregated. Read-only, safe every Newton iteration (trial’s own doc comment); calling it at a section’s current committed (eps0, kappa) reproduces that fiber’s committed stress exactly, the same “recompute, don’t cache” pattern ZeroLength::local_force relies on.

Trait Implementations

impl Clone for FiberSection

fn clone(&self) -> FiberSection

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for FiberSection

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

Formats the value using the given formatter.