This program determines section properties for built up sections with rectangles, hollow circles, solid circles, and standard AISC steel sections.

AISC sections can be recalled from the database files and included in the built-up section. W and C sections from the 6th, 7th, 8th, and 9th edition handbooks are available. They can be rotated 90 deg, 180 deg, or 270270 deg desired

Calculated section property values are area, moments of inertia, center of gravity location, extreme fiber distances, section moduli, and radius of gyration.

 

 

Basic Usage

Before starting data entry, be sure you have set up an X/Y coordinate system to consistently reference all component locations.

For each rectangular shape, enter the height, width, and center of area from the datum.

Circular sections are entered by specifying the outside radius and thickness. The radius is measured from the center to the outside of the circular shape. Set thickness to zero for solid sections, or non-zero for hollow pipes.

For AISC sections, this distance will locate the section's centroid position. The program knows the centroid location of AISC members with respect to their own extreme fiber locations. However, you need to enter the location of the shape's actual centroid in relation to the other rectangular and/or circular shapes. Be careful, as this can be tricky when entering channels, angles, and tee sections that are rotated.

This program will allow entry of solid circular or pipe sections. When a solid circular section is to be used, the user simply enters 0" for thickness of the circular shape.

A unique feature allows the user to specify whether the X and Y axes of AISC sections should be turned +/-90 degrees.

 

Assumptions & Limitations

The program operates on a simple calculation procedure:

 

More complex analysis such as polar moment of inertia, plastic moduli, and buckling constants are beyond the scope of the program.

To calculate the section modulus, the program checks for the most distant portion of any shape from the calculated neutral axis on all four sides. The appropriate X-X or Y-Y moment of inertia is then divided by this distance (fiber distance) to get the section modulus for each of the four sides.

 

Example

The data entry for this example is shown in the screen captures that accompany the Data Entry Tabs and Results & Graphics Tabs sections to follow.

 

 

Data Entry Tabs

This set of tabs provides entries for all input in this calculation. While you are entering data and switching between these tabs you can view the desired resulting information on the tabs on the right-hand side of the screen (calculated values, sketches, diagrams, etc.). A recalculation is performed after any entry data is changed. After each data entry you can view the results on the right-hand set of tabs.

 

General Tab

This tab provides all the data entry locations. It is divided into two areas: (1) to define rectangular and circular shapes and (2) To add AISC rolled sections.

 

 

 

General Shapes

This area contains small tabs #1 thru #10 which each are used to define a rectangular or circular item. The screen image above shows data entry for a rectangular section. By changing the drop-down box to "Circular" you would see the entry prompts below:

 

 

Each shape input provides for the size of the item and the X & Y distance from a datum point where the CENTER OF GRAVITY of the section is located.

 

Also note that for "Circular" section types you can enter the inside diameter thus allowing solid circles and hollow pipes.

 

Rectangles

Enter the dimensions of square or rectangular shapes to be included in the analysis on each line. Also, enter the location of the center of gravity of this shape with respect to a datum point you have chosen. Distances from the datum can be positive or negative.

 

Circular Sections

Enter the dimensions of solid circular or hollow pipe shapes to be included in the analysis in this location. Also, enter the location of the center of gravity of this shape with respect to a datum point you have chosen. Distances from the datum can be positive or negative. The Radius entry means the outside radius.

To specify a solid circular section, set the entry for Thickness equal to zero. This will signal the program that the circular section is solid. For any other circular shape that has a hollow circular core, enter the wall thickness (not the inner diameter).

 

Distance to C.G.

This distance locates the center of area of each shape with respect to a datum. Locations may be positive or negative.

 

       AISC Rolled Shapes

In the lower area of the tab you see five smaller tabs that provide data entry locations for up to five rolled AISC sections. To specify a section t be used either type in the section name in the entry area and press the [Tab] key -or- use the [Section] button to use the built in steel section database.

 

Angle 0/90 deg.

This entry allows you to orient the section at 0, 90, or -90 degrees. 0 degrees specifies the typical orientation with the Y-Y axis vertical. 90 degrees rotates the section counterclockwise 90 degrees. -90 degrees will rotate the section clockwise 90 degrees (to allow channels to be oriented open end down).

 

Results & Graphics Tabs

This set of tabs provides the calculated values resulting from your input on the "Data Entry Tabs". Because a recalculation is performed with each data entry, the information on these tabs always reflects the accurate and current results, problem sketch, or stress/deflection diagram.

 

 

Total Area

The total area of all defined shapes, including the area of any AISC sections which have been included in the analysis.

 

X Distance to Center of Gravity

Using the locations of the center of gravity of each entered shape and AISC section data, static moments are taken about each  X  and  Y  datum and the center of gravity distance from the datum is determined.

 

Edge Distance from C.G.

This is the distance from the Center of Gravity (more properly the center of area) of the composite section to the most extreme fiber in each direction.

 

Inertia : Ixx & Iyy

The overall moment of inertia of the composite section is determined by applying the following equation to all the defined shapes:

                            I-xx + (A * dy2) and I-yy + (A * dx2)

where  d  = Distance from the shape's C.G. to the overall C.G. of the composite section.

 

Radius of Gyration

The radius of gyration of the composite section is determined using the typical equation:  ( Ixx / A )½  and ( Iyy / A )½

 

Section Modulus : S

These values are the calculated section moduli of the composite section. The values are determined by dividing Ixx or Iyy by the fiber distances above, below, right, and left of the center of gravity of the section.

 

Sketch Tab

This tab provides a sketch of the beam with loads and resulting values shown. Using the [Print Sketch] button will print the sketch in large scale on a single sheet of paper.

 

 

Sample Printout