conspire/domain/fem/block/element/surface/linear/triangle/
mod.rs1#[cfg(test)]
2pub mod test;
3
4use crate::{
5 fem::block::element::{
6 ElementNodalEitherCoordinates, FiniteElement, ParametricCoordinate, ParametricCoordinates,
7 ParametricReference, ShapeFunctions, ShapeFunctionsGradients,
8 surface::{M, linear::LinearSurfaceElement},
9 },
10 math::{ScalarList, Tensor},
11};
12use std::f64::consts::FRAC_PI_3;
13
14const G: usize = 1;
17const N: usize = 3;
18const P: usize = N;
19
20pub type Triangle = LinearSurfaceElement<G, N>;
21
22impl FiniteElement<G, M, N, P> for Triangle {
23 fn integration_points() -> ParametricCoordinates<G, M> {
24 [[1.0 / 3.0; M]].into()
25 }
26 fn integration_weights(&self) -> &ScalarList<G> {
27 &self.integration_weights
28 }
29 fn parametric_reference() -> ParametricReference<M, N> {
30 [[0.0, 0.0], [1.0, 0.0], [0.0, 1.0]].into()
31 }
32 fn parametric_weights() -> ScalarList<G> {
33 [1.0 / 2.0; G].into()
34 }
35 fn scaled_jacobians<const I: usize>(
36 nodal_coordinates: ElementNodalEitherCoordinates<I, N>,
37 ) -> ScalarList<P> {
38 let sin_60 = FRAC_PI_3.sin();
39 angles(nodal_coordinates)
40 .into_iter()
41 .map(|angle| angle.sin() / sin_60)
42 .collect()
43 }
44 fn shape_functions(parametric_coordinate: ParametricCoordinate<M>) -> ShapeFunctions<N> {
45 let [xi_1, xi_2] = parametric_coordinate.into();
46 [1.0 - xi_1 - xi_2, xi_1, xi_2].into()
47 }
48 fn shape_functions_gradients(
49 _parametric_coordinate: ParametricCoordinate<M>,
50 ) -> ShapeFunctionsGradients<M, N> {
51 [[-1.0, -1.0], [1.0, 0.0], [0.0, 1.0]].into()
52 }
53}
54
55fn angles<const I: usize>(nodal_coordinates: ElementNodalEitherCoordinates<I, N>) -> ScalarList<N> {
56 let l_10 = (&nodal_coordinates[1] - &nodal_coordinates[0]).normalized();
57 let l_02 = (&nodal_coordinates[0] - &nodal_coordinates[2]).normalized();
58 let l_21 = (&nodal_coordinates[2] - &nodal_coordinates[1]).normalized();
59 [
60 (-&l_02 * &l_10).acos(),
61 (-l_10 * &l_21).acos(),
62 (-l_21 * l_02).acos(),
63 ]
64 .into()
65}