This project is a collection of modules for solving mechanics models. So far, its capable of solving the plane problem using the Finite Element Method with a simple quadrilateral element with linear shape functions.
scikit-mechanics was designed so its really simple to perform a mechanical analysis.
The first step is to set up a mesh file, I recommed using gmsh for that.
The mesh file (.msh) follows the formatting:
$MeshFormat 2.2 0 8 $EndMeshFormat $Nodes 4 1 0 0 0 2 0.001 0 0 3 0.001 0.001 0 4 0 0.001 0 $EndNodes $Elements 5 1 1 2 2 1 1 2 2 1 2 3 2 2 3 3 1 2 4 3 3 4 4 1 2 1 4 4 1 5 3 2 3 10 1 2 3 4 $EndElements
which represents a single element with 4 nodes, and 5 elements. The elements with type 1 (second number) indicates lines with two nodes, are specified as physical elements for applying boundary conditions. The element type 3 is the quadrilateral element.
This file is then used to perform a static analysis:
import skmech
E, nu, H, sig_y = 250e9, 0.25, 50e9, 2.5e6 # Pa, -, Pa, Pa
msh = skmech.Mesh('one.msh')
displbc = {1: (0, None), 2: (None, 0)}
mat = skmech.Material(E={3: E},
nu={3: nu},
H={3: H},
sig_y0={3: sig_y},
case='strain')
trac = {3: (5e6, 0)} # boundary condition on physical element 3
model = skmech.Model(
msh, material=mat, displacement_bc=displbc,
thickness=1e-3, traction=trac)
u = skmech.statics.solver(model)
sig = skmech.postprocess.stress_recovery_smoothed(model)
sig_x = {nid: sig[nid][0] for nid in model.nodes.keys()} # x-component
# save to post processing file
skmech.gmshio.write_field(u, 'one', 'Displacement', ndim=2)
skmech.gmshio.write_field(sig_x, 'one', 'Sigma x', ndim=1)which can be visualized in gmsh,
