Civil Engineering Reference
In-Depth Information
nf
nodal freedom matrix
no
fixed freedoms vector
node
fixed nodes vector
element node numbers vector
num
Dynamic real arrays:
action
element nodal action vector
element displacement vector
eld
element lengths vector
ell
element stiffness matrix
km
global stiffness matrix
kv
global load (displacement) vector
loads
element properties matrix
prop
fixed displacements vector
value
The main features of this program are the elastic rod element stiffness matrix (2.11)
and the global stiffness matrix assembly described in Section 3.7. The structure chart in
Figure 4.1 gives the main sequence of operations.
Program 4.1 is illustrated by two examples shown in Figures 4.2 and 4.3. In both cases,
the rod is restrained at one end and free at the other. The rod in Figure 4.2 is subjected to
a uniformly distributed axial force of 5.0/unit length, and the rod in Figure 4.3 is subjected
to a fixed displacement of 0.05 at its tip.
Read data.
Allocate arrays.
Find problem size.
Null global stiffness matrix.
For all elements
Find steering vector.
Compute element stiffness matrix.
Assemble global stiffness matrix.
Factorise the global stiffness matrix.
Read the loads and/or displacements.
Complete equation solution.
Print displacements.
For all elements
Find the element nodal displacements.
Compute and print nodal "actions".
Figure 4.1
Structure chart for Program 4.1
