# EX. US-20 Generating a Structure in Cylindrical Coordinates

This example generates the geometry of a cylindrical tank structure using the cylindrical coordinate system. The tank lies on its side in this example.

This problem is installed with the program by default to C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\Samples\Sample Models\US\US-20 Generating a Structure in Cylindrical Coordinates.STD when you install the program.

### Example Problem No. 20

In this example, a cylindrical tank is modeled using finite elements. The radial direction is in the XY plane and longitudinal direction is along the Z-axis. Hence, the coordinates in the XY plane are generated using the cylindrical coordinate system.

```    STAAD SPACE
```
```    UNIT KIP FEET
```

The type of structure (space frame) and length and force units for data to follow are specified.

```    JOINT COORD CYLINDRICAL
```

The above command instructs the program that the coordinate data that follows is in the cylindrical coordinate system (r,theta,z).

```    1 10 0 0 8 10 315 0
```

Joint 1 has an 'r' of 10 feet, theta of 0 degrees and Z of 0 ft. Joint 8 has an 'r' of 10 feet, theta of 315 degrees and Z of 0 ft. The 315 degrees angle is measured counter-clockwise from the +ve direction of the X-axis. Joints 2 to 7 are generated by equal increments of the coordinate values between joints 1 and 8.

```    REPEAT 2 0 0 8.5
```

The REPEAT command is used to generate joints 9 through 24 by repeating twice, the pattern of joints 1 to 8 at Z-increments of 8.5 ft for each REPEAT.

```    PRINT JOINT COORD
```

The above command is used to produce a report consisting of the coordinates of all the joints in the Cartesian coordinate system. Note that even though the input data was in the cylindrical coordinate system, the output is in the Cartesian coordinate system.

```    ELEMENT INCIDENCES
1 1 2 10 9 TO 7 1 1
8 8 1 9 16
REPEAT ALL 1 8 8
```

The above 4 lines identify the element incidences of all 16 elements. Incidences of element 1 is defined as 1 2 10 9. Incidences of element 2 is generated by incrementing the joint numbers of element 1 by 1, incidences of element 3 is generated by incrementing the incidences of element 2 by 1 and so on up to element 7. Incidences of element 8 has been defined above as 8 1 9 16. The REPEAT ALL command states that the pattern of all the elements defined by the previous 2 lines, namely elements 1 to 8, must be repeated once with an element number increment of 8 and a joint number increment of 8 to generate elements 9 through 16.

```    PRINT ELEMENT INFO
```

The above command is self-explanatory.

```    FINISH
```

## Input File

``````STAAD SPACE
UNIT KIP FEET
JOINT COORD CYLINDRICAL
1 10 0 0 8 10 315 0
REPEAT 2 0 0 8.5
PRINT JOINT COORD
ELEMENT INCIDENCES
1 1 2 10 9 TO 7 1 1
8 8 1 9 16
REPEAT ALL 1 8 8
PRINT ELEMENT INFO
FINISH
``````

```                                                                  PAGE NO.    1
****************************************************
*                                                  *
*           Version  22.08.00.***                  *
*           Proprietary Program of                 *
*           Bentley Systems, Inc.                  *
*           Date=    OCT 19, 2021                  *
*           Time=    17:55:13                      *
*                                                  *
*  Licensed to: Bentley Systems Inc                *
****************************************************
INPUT FILE: US-20 Generating a Structure in Cylindrical Coordinates.STD
2. UNIT KIP FEET
3. JOINT COORD CYLINDRICAL
4. 1 10 0 0 8 10 315 0
5. REPEAT 2 0 0 8.5
6. PRINT JOINT COORD
JOINT    COORD
STAAD SPACE                                              -- PAGE NO.    2
JOINT COORDINATES
-----------------
COORDINATES ARE FEET UNIT
JOINT            X              Y              Z
1           10.000          0.000          0.000
2            7.071          7.071          0.000
3            0.000         10.000          0.000
4           -7.071          7.071          0.000
5          -10.000          0.000          0.000
6           -7.071         -7.071          0.000
7           -0.000        -10.000          0.000
8            7.071         -7.071          0.000
9           10.000          0.000          8.500
10            7.071          7.071          8.500
11            0.000         10.000          8.500
12           -7.071          7.071          8.500
13          -10.000          0.000          8.500
14           -7.071         -7.071          8.500
15           -0.000        -10.000          8.500
16            7.071         -7.071          8.500
17           10.000          0.000         17.000
18            7.071          7.071         17.000
19            0.000         10.000         17.000
20           -7.071          7.071         17.000
21          -10.000          0.000         17.000
22           -7.071         -7.071         17.000
23           -0.000        -10.000         17.000
24            7.071         -7.071         17.000
************ END OF DATA FROM INTERNAL STORAGE ************
7. ELEMENT INCIDENCES
8. 1 1 2 10 9 TO 7 1 1
9. 8 8 1 9 16
10. REPEAT ALL 1 8 8
11. PRINT ELEMENT INFO
ELEMENT  INFO
STAAD SPACE                                              -- PAGE NO.    3
ELEMENT INFORMATION
-------------------
ELEMENT           INCIDENCES         THICK   POISS    E1/E2        G1/G2        AREA
NO.                                (FEET)
1       1      2     10      9    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
2       2      3     11     10    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
3       3      4     12     11    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
4       4      5     13     12    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
5       5      6     14     13    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
6       6      7     15     14    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
7       7      8     16     15    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
8       8      1      9     16    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
9       9     10     18     17    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
10      10     11     19     18    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
11      11     12     20     19    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
12      12     13     21     20    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
13      13     14     22     21    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
14      14     15     23     22    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
15      15     16     24     23    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
16      16      9     17     24    0.000  0.000 0.000000E+00 0.000000E+00 6.505619E+01
0.000000E+00 0.000000E+00
******************END OF ELEMENT INFO******************
12. FINISH
STAAD SPACE                                              -- PAGE NO.    4
*********** END OF THE STAAD.Pro RUN ***********
**** DATE= OCT 19,2021   TIME= 17:55:13 ****
************************************************************