|
Yes, CAST can be used to design statically indeterminate strut-and-tie
models. However, the current version of CAST only permits elastic distribution of forces in the Strut-and-Tie Model components, i.e., Struts and Ties. In order to obtain reasonable force distribution in this manner, you must first
estimate the Relative Stiffnesses between the Strut-and-Tie components and then supply the values to
CAST. Note that Relative Stiffness of an STM Element represents compressive or tensile rigidity, EA, of an STM Element relative to other STM Elements, where: E = modulus of elasticity and A = effective area.
By default, CAST assumes that all
Struts and Ties have a Relative Stiffness of 1.0. To supply Relative Stiffnesses of Struts or Ties:
- Click
 on the button
from the Selecting toolbar to be in the Select mode.
- Select the Struts and Ties whose Relative Stiffnesses are to be
changed to the same level.
- Click
on the
 button from the
Assigning toolbar (or click the Relative Stiffnesses and Widths menu from the Assign
menu). The Assign Relative Stiffnesses and Widths dialog box as shown in
Figure 1.1 will appear on the screen.
Figure 1.1 The Assign Relative Stiffnesses and Widths Dialog Box
- Type in the level of Relative Stiffness in the Relative Stiffness text box.
- Leave the Provided Effective Width text box blank.
- Uncheck the Automatic Calculation of Effective Width of Struts checkbox.
- Click the OK button to confirm the change and close the dialog box.
- Repeat the above steps for other Struts and Ties having the
same level of Relative Stiffness.
|
Q & A