Struct GridShell 

pub struct GridShell {
    pub rows: usize,
    pub cols: usize,
    pub nodes: Vec<V3>,
    pub members: Vec<(usize, usize)>,
    pub rest_lengths: Vec<f64>,
    pub stiffnesses: Vec<f64>,
    pub fixed_nodes: Vec<usize>,
    pub nodal_mass: Vec<f64>,
}

A doubly-curved grid shell structure.

Nodes are arranged in a regular grid (rows × cols) with initial positions on a parametric surface. Members connect neighbouring nodes. Form-finding is performed via dynamic relaxation — nodes are moved iteratively towards equilibrium under prestress and applied loads.

Fields

rows: usize

Number of rows in the grid.

cols: usize

Number of columns in the grid.

nodes: Vec<V3>

Current 3-D positions of all nodes (row-major).

members: Vec<(usize, usize)>

Member connectivity: pairs of node indices.

rest_lengths: Vec<f64>

Natural (unstressed) length of each member (m).

stiffnesses: Vec<f64>

Axial stiffness EA for each member (N).

fixed_nodes: Vec<usize>

Pinned (fixed) node indices.

nodal_mass: Vec<f64>

Lumped mass at each node (kg) — used in dynamic relaxation.

Implementations

impl GridShell

pub fn parabolic( rows: usize, cols: usize, span_x: f64, span_y: f64, sag: f64, ) -> Self

Construct a parabolic grid shell spanning span_x × span_y metres, with a rise of sag metres at the centre.

rows and cols define the number of grid points in each direction. The boundary nodes are automatically pinned.

pub fn dynamic_relaxation( &mut self, max_iter: usize, dt: f64, damping: f64, tol: f64, ) -> f64

Run max_iter steps of dynamic relaxation.

Returns the maximum residual force at any free node after convergence. A value below tol (N) indicates equilibrium has been achieved.

pub fn max_member_force(&self) -> f64

Compute maximum member force (N) in the current configuration.

pub fn node_count(&self) -> usize

Total number of nodes.

pub fn member_count(&self) -> usize

Total number of members.

Trait Implementations

impl Clone for GridShell

fn clone(&self) -> GridShell

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for GridShell

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

Formats the value using the given formatter.