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Tutorial 02

Solid Cantilever

Goal

Solve the same cantilever problem from Tutorial 01, but with solid elements.

The purpose is:

  • to understand why solid models require more input than beam models
  • to experience the result-review advantages of a solid model

When a solid model is more appropriate

Use solids when:

  • you want direct stress distribution through the section
  • you need to inspect local stress concentration
  • the geometry is too complex for simple section assumptions

Tutorial case

This tutorial uses the same reinforced-concrete cantilever from Tutorial 01, but models the full 3D block.

  • geometry: 2.4 m x 0.30 m x 0.60 m
  • element type: C3D8
  • mesh: 8 x 2 x 4
  • support: full fixity on the x=0 face
  • load: 60 kPa downward pressure on the top face

Because the beam width is 0.30 m, the 60 kPa top pressure corresponds to the same 18 kN/m line load used in the beam tutorial. That makes the two tutorial models directly comparable.

Working input file

Repository file: Example/Tutorials/tutorial-solid-cantilever.inp

*Material, Type=IsoElasticity, Name=Concrete
 30e9, 0.2, 0, 2500   # E, nu, alpha, density

*Section, Type=Solid, Name=ConcreteSolid
 Concrete, 1

*Model, Type=Block3D
 Cantilever, Auto, Auto, C3D8, ConcreteSolid
 0.0, 2.4, 8
 0.0, 0.30, 2
 0.0, 0.60, 4

*Constraint, Type=Support, Name=FixedEnd
 Cantilever-NX, X|Y|Z

*Load, Type=SurfaceDistributed, Name=DeckPressure
 Cantilever-PZ, Pressure, 60000

*Step, Type=Static, Name=Service
 Uniform, 0.1, 1
*Activate, Type=Element
 Cantilever
*Activate, Type=Constraint
 FixedEnd
*Activate, Type=Load
 DeckPressure
*Output
 D, S
*Print, File=tutorial-solid-cantilever.prn
 D@Cantilever

Modeling sequence

  1. define the material and solid section
  2. Material
  3. Solid Elements
  4. generate the 3D block mesh
  5. Model
  6. define the fixed-end support on the left face
  7. define the top-face pressure load
  8. define the static service step and run the solver

What changes relative to the beam model

  • the number of nodes and elements grows quickly
  • both modeling time and analysis time increase
  • in return, stress contours are much more direct

Run the analysis

Remote Control example:

hfVisualizer --remote import D:\Work\tutorial-solid-cantilever.inp --type Hyfeast
hfVisualizer --remote save D:\Work\tutorial-solid-cantilever.h5.hdb
hfVisualizer --remote run-analysis

What to review

  • whether the free-end displacement is in the same range as the beam model
  • how the stress distribution appears near the fixed end
  • how sensitive the result is to mesh refinement

Postprocessing example:

hfVisualizer --remote post-step Service
hfVisualizer --remote post-frame 1
hfVisualizer --remote post-plot contour on
hfVisualizer --remote post-plot deformed on
hfVisualizer --remote post-scalar S.Mises
hfVisualizer --remote post-display scalarbar on

The following image shows the same cantilever in hfVisualizer with deformed shape and von Mises stress contour.

Solid cantilever contour result in hfVisualizer

Practical takeaway

  • If you only need global behavior, beam modeling is faster.
  • If detailed stress review matters, solid modeling is more persuasive.
  • A common workflow is beam first, solid later for local detail.

Next step