run.jl

# ===========================================================================
#  PhaseFieldFracture — a readable, pure-Julia phase-field fracture solver
#
#  Author:     Yang Bai — Materials Mechanics Laboratory (MMLab)
#  Contact:    yangbai90@outlook.com
#  Copyright:  © 2026 Materials Mechanics Laboratory (MMLab). All rights reserved.
# ===========================================================================

# ===========================================================================
#  Driver: single-edge-notched tension test (SENT)
# ===========================================================================
#
#  Run with:   julia run.jl
#
#  A square plate [-0.5,0.5]² with a horizontal pre-crack from the left edge to
#  the centre is pulled apart by prescribing a vertical displacement on the top
#  edge while the bottom edge is clamped.  The crack grows to the right.

include("PhaseFieldFracture.jl")
using .PhaseFieldFracture

# ---------------------------------------------------------------------------
#  Geometry and mesh  (keep ny even so mesh nodes lie on the crack line y = 0)
# ---------------------------------------------------------------------------
mesh  = rectangle_mesh(100, 100; x0 = -0.5, x1 = 0.5, y0 = -0.5, y1 = 0.5)
crack = crack_line_nodes(mesh; crack_y = 0.0, tip_x = 0.0)

# ---------------------------------------------------------------------------
#  Material  (E in MPa, lengths in mm, Gc in N/mm are a consistent unit set)
# ---------------------------------------------------------------------------
#  `split` selects the tension/compression model of the elastic energy:
#    :spectral  Miehe's principal-strain split — only tension drives/degrades the
#               crack (the physically correct default; see strainsplit.jl), or
#    :none      no split — the whole energy drives and is degraded (classic model;
#               will also crack under compression, which is unphysical).
material = Material(E = 210_000.0, ν = 0.30, Gc = 2.7, ℓ = 0.04, k = 1e-8, split = :spectral)

# ---------------------------------------------------------------------------
#  Solver settings
# ---------------------------------------------------------------------------
settings = Settings(nsteps = 50, umax = 8e-3, max_iter = 50, tol = 1e-6, out_every = 5)

# ---------------------------------------------------------------------------
#  Assemble the problem and run
# ---------------------------------------------------------------------------
problem = Problem(mesh, material, settings, crack, "output", "HistoryOutput.txt")

println("Running the clean phase-field fracture example (", nnodes(mesh), " nodes)...")
@time u, φ, H = run_simulation(problem)

println()
println("Finished.")
println("History file:     ", problem.histfile)
println("ParaView series:  ", joinpath(problem.outdir, "timeseries.pvd"), "  (open this in ParaView)")
println("Snapshots:        ", joinpath(problem.outdir, "field_XXXX.vtu"))
println("Final max φ:      ", maximum(φ))