5 EXAMPLES
5.0 OVERVIEW
You will find several examples in this chapter along with their
respective input files B*.* on the Z88 diskettes. The examples
4, 6 and 7 can be calculated analytically by hand.
Work with the examples which resemble your own applications. Also
look at the protocol files *.LOG produced by the Z88 modules.
Plot the various examples and results on
your plotter or your laser printer capable of HP-GL. Vary the
input files, especially the net generator-input files for the
examples 1, 5 and 7. Doing so gives you a smart feeling for the
howtos of Z88 very quick.
If examples do not run, first search for memory problems.
Are there any other programs in the computer's memory, especially
those fat and greedy memory eaters like office packages? All examples
were tested on various computer equipment and operating systems,
and all examples do run even on oldfashioned 386s with 8 MB of
RAM along with Windows 95 or the powerful LINUX. Additionally,
Z88 is running very large structures on a Silicon Graphics UNIX
machine with 6 GB of RAM without any problems. If necessary, adjust
Z88.DYN. Investigate the *.LOG files:
It is shown here if Z88 modules run out of memory. UNIX: Check
file and directory permissions.
After you have investigated the ready-to-run examples, try to
draw the examples in your CAD program. Export to DXF files and
convert them into Z88 files. If the CAD converter
does not convert your DXF files properly, then redo the steps
3 and 5 of chapter 2.6.2, pg. 40 & 41. Did you "snap"
the points cleanly ? If nothing works try another CAD program.
Example 1: Fork wrench. Plane stress
problem with Serendipity Plane Stress No.7
and net generator use. Learning objectives: CAD and net generator
use at curvilinear plane structures, displaying stresses in the
plot program. This example is fixed on the Z88 diskette ready
to run as the first introduction example with Z88X.DXF, Z88I2.TXT
and Z88I3.TXT.
Example 2: Crane truss. Modelled
with Trusses No.4. Learning objectives:
Use of the different views and rotation possibilities in space
within the plot program.
Example 3: Transmission cam. Cam
with different diameters, forces and moments in different planes
with cam elements No.5, statically overdefined.
Learning objectives: Use of the cam elements, especially for the
boundary conditions at finite elements with 6 degrees of freedom
per node, use of the different views in the plot program.
Example 4: Beam in plane, repeatedly
statically overdefined. On both sides firmly fixed Beam No.13.
Learning objectives: Use of Beams No.13, choice of the boundary
conditions and the interpretation of the results.
Example 5: Disk segment in cake
form. General spatial problem with Hexahedrons No.10
(20 nodes) as super elements and net generation of Hexahedrons No.1
(8 nodes). Learning objectives: Use of the net generator at curvilinear
spatial elements, showing stresses, different views and spatial
rotation possibilities in the plot program. After running this
example successfully it is a nice idea to make the net generator
generating Hexahedrons No.10 instead of Hexahedrons No.1, what
is just a breeze. But you must define new nodes for the boundary
conditions.
Example 6: Pipe under inner pressure
of 1,000 bar. Axially symmetric problem, solved as plane stress
problem with Plane Stress Elements No.7.
Learning objectives: Clever use of symmetry qualities of a structure
and choice of the proper boundary conditions, showing stresses
in the plot program.
Example 7: Press fit. Axially symmetric
problem with Tori No.8 and use of net
generator. Learning objectives: Work with torus elements, use
of the net generator with net compression, stress display in the
plot program.
Example 8: Crankshaft. Space structure
with Tetrahedrons No.16. Learning objectives:
Starting with a COSMOS file from Pro/ENGINEER, we will use the
COSMOS converter Z88G, the Cuthill- McKee program Z88H and both
the solvers, i.e. the direct Cholesky solver Z88F and the iteration
solver Z88I1/Z88I2. This is an example for a larger FEA structure
imported from a CAD system.
Example 9: Rectangular plate with
16 nodes Lagrange plate elements No.19.
Learning objectives: Starting with an AutoCAD drawing for a super
structure with plates No.20, we'll export the DXF file to the
CAD converter Z88X. Running the mesh generator Z88N will generate
a mesh of plates No.19. The system will be solved by the iteration
solver.
Notes: