Example 2a. Elastic Cantilever Column with variables


The objective of this example is to demonstrate the use of variables in defining the OpenSees input.
a. Static Pushover	b. Dynamic EQ Ground Motion
Ex2a.Canti2D.ElasticElement.Push.tcl	Ex2a.Canti2D.ElasticElement.EQ.tcl BM68elc.acc (ground-motion file)

In this example, all input values for Example 1a are replaced by variables.

For example, the following series of commands from Example 1a:

# define GEOMETRY # nodal coordinates:

node 1 0 0; # node#, X Y

node 2 0 432

was replace with the following series of commands in Example 2a:

# define GEOMETRY

set LCol 432; # column length

# nodal coordinates:

node 1 0 0; # node#, X, Y

node 2 0 $LCol

While the use of variables may seem more time consuming in the simple examples, it is very effective in large examples. The following is a list of some of the advantages of using variables:

Reduced error and easier error checking because values are defined one time only.
Easy to change values of model parameters
Reduced amount of documentation within a file

The response curves for this example (obtained from the recorders' files DFree.out RBase.out) are as follows:

Ex2a.Canti2D.ElasticElement.Push.tcl:

Ex2a.Canti2D.ElasticElement.EQ.tcl: