DESCRIPTION - FOLDED PLATE PROGRAM

(Note:  This program was wrtten in English Units: Input = Feet, Kips (1000 pounds), Output = PSI (pounds per square foot) and foot pounds. International useres becareful..)

1.  This program comes is two sections.
FOLDP-PR.BAS, for the preparation of data, and
FOLDP-AN.BAS, for the analysis.

2.   Data input for the first part is in DATA statements at locations, 2000, and 3000. (Two sets).  Both examples are described by REM statements. The program to be analysed can be changed by altering the RESTORE statement at location 45.  It is suggested that you RUN this program to show the operation.  This program allows you to save the data for the next part and you must select the name of the file (I have use the code D-filename, (omit .BAS).  The program shows all the files in your folder so you can see what you have.

3.   The program has the following features: (1) You can vary the thickness of a member. (2)  You can change the moment of inertia without changing the thickness, thus allowing waffle slabs. (3) You can eliminate the shell action of a member, thus allowing the edge to be supported by a column.  (4) You can allow almost any end or support condition. (Fixed, symmetry, free, etc.)  (5) You can perform a geometric non-linear analysis of the structure by successive re-analysis using the new deflections at each step.  Study the DATA statements carefully to see how these features are obtained.

4.  The analysis program accepts the input from the first part. Run the program to see how this is done.  First the program make a frame analysis of the structure assuming that locations at folds are fixed but others are free to move.  Then the program uses this data to make the folded plate analysis. 

Description of Examples (See drawing for sketches)

Four Element Folded Plate (Location 3000)

This structure is a typical interior bay of a folded plate. The span is 40 feet and the spacing is 20 feet.  The folded plate is generally 4 inches thick and is composed of four elements.  At the valleys the shell is thickened to 8 inches for a distance of 2.5 feet from the valleys.  Note that the nodes are labeled with their characteristic function: (SY=symmetry. N= no fold F=fold.  See the program for these labels).  The live load is 20psf.  The program calculates the dead load, except for the roofing etc.  Run the example and see the results.

Folded Plate Vault (Location 2000)

This is a vault (single barrel) with a span of 300 feet and a width of 90 feet. Other dimensions are shown on the sketch. The slab is a waffle slab except near the nodes where it is solid for strength purposes.  The edges are supported by columns which do not participate in the folded plate action. The analysis for a unit width, so the stiffness of the columns must  be divided by the spacing.  The columns are partially fixed by  extending the column below the base.  The live loads for this example are ultimate loads.

 



