Tested with CGX 2.16 / CCX 2.15
- Test of beam elements
| File | Contents |
|---|---|
| b32.inp | CCX input for B32 element |
| b32.fbd | CGX pre/post input for B32 element |
| u1general.inp | CCX input for user element U1 with general beam section |
| u1.plt | Gnuplot script for the U1 example |
| test.py | Python script to run the full simulation |
Structure: Cantilever beam (length 100 mm, square section 10 x 10 mm) with a point load of 1 kN at the free end. Material is steel with E = 210 GPa and nu = 0.3.
Click the image below to open a life worksheet:
This element is internally expanded into C3D20R solid elements. Prescribed rotations are internally converted into mean rotation MPCs.
> cgx -b b32.fbd
For the given mesh density, the displacement is 3% lower than the reference value and converges to it for higher density.
This element is mentioned in the CCX handbook version 2.15 in section 6.2.45.
*ELEMENT, TYPE=U1, ELSET=Eall
1, 1, 2,
...
*USER ELEMENT,TYPE=U1,NODES=2,INTEGRATION POINTS=2,MAXDOF=6
...
*BEAM SECTION,ELSET=Eall,MATERIAL=EL,SECTION=GENERAL
100.,833.3,0.,833.3,0.8333
0.,1.,0.
...
For meshing you can specify be2 elements in CGX and then rename the element type to U1 in the mesh file. In the given example, the mesh was generated manually directly in the INP file.
Run the analyis, extract the data and plot the displacement:
> ccx u1general
> sed -n '4,14 p' u1general.dat > u1.txt
> gnuplot u1.gpl
The field results (FRD) are unusable. They neither contain the mesh nor any results. For results checking you have to rely on the DAT file.
The following image shows the displacement UZ and the rotation RY along the beam.
