calculate 2d beam element stiffness matrix

src/bin/two_d.rs

@@ -0,0 +1,70 @@
+use fea::two_d::beam_elements::*;
+use fea::two_d::*;
+
+fn main() {
+    let student_id_last_digit = 9 as f32;
+    let d = student_id_last_digit / 100.0;
+    let r = d/2.0;
+    let e = 210e9;
+    let p = (25.0 - student_id_last_digit)*1000.0;
+    let theta = 30.0_f32.to_radians();
+    let l = 2.0/theta.cos();
+
+    let p1 = Point{
+        id: 1,
+        pos: Vector(0.0, 0.0),
+        bc: BoundaryCondition::Fixed,
+        beams: vec![],
+    };
+
+    let p2 = Point {
+        id: 2,
+        pos: Vector(0.0, l * theta.sin()),
+        bc: BoundaryCondition::Force(Vector(0.0, 1000.0)),
+        beams: vec![],
+    };
+
+    let l_e3 = 2.0/theta.sin();
+    println!("l_e3 {l_e3}");
+
+    let p3 = Point {
+        id: 3,
+        pos: Vector(0.0, (l * theta.sin()) + (l_e3 * theta.cos())),
+        bc: BoundaryCondition::Fixed,
+        beams: vec![],
+    };
+
+    let p4 = Point {
+        id: 4,
+        pos: Vector(l * theta.cos(), l * theta.sin()),
+        bc: BoundaryCondition::Force(Vector::from_mag_angle(p, 45_f32.to_radians())),
+        beams: vec![]
+    };
+
+    let mut w = World::from(vec![p1, p2, p3, p4]);
+
+    w.link(1,4, NewBeam {
+        cross_section: CrossSection::Circular(r),
+        material: fea::Material {
+            yield_stress: 95e6,
+            youngs_modulus: e,
+        }
+    }).unwrap();
+    w.link(2,4, NewBeam {
+        cross_section: CrossSection::Circular(r),
+        material: fea::Material {
+            yield_stress: 95e6,
+            youngs_modulus: e,
+        }
+    }).unwrap();
+    w.link(3,4, NewBeam {
+        cross_section: CrossSection::Circular(r),
+        material: fea::Material {
+            yield_stress: 95e6,
+            youngs_modulus: e,
+        }
+    }).unwrap();
+
+    println!("{:?}", w);
+    println!("{:?}", w.stiffness_matrix().unwrap());
+}