V. 2D Portal Reactions 2

Find the maximum moment due to a uniform load on the horizontal member in a 1x1 bay plane frame.

Reference

McCormac, J. C., Structural Analysis, Intext Educational Publishers, 3^rd edition, 1975, page 383, example 22 - 5.

Problem

Determine the maximum moment in the frame.

E and I same for all members.

L = 20 ft

w = 2 kips/ft

1x1 bay plane frame

Comparison

Table 1. Comparison of results
Result Type	Theory	STAAD.Pro	Difference
M_Max (kip·ft)	44.40	44.44	negligible

STAAD Input

The file C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\Samples\ Verification Models\03 Frames\2D Portal Reactions 2.STD is typically installed with the program.

STAAD PLANE : 2D PORTAL REACTIONS
START JOB INFORMATION
ENGINEER DATE 17-Sep-18
END JOB INFORMATION
*
*  REFERENCE 'STRUCTURAL ANALYSIS' BY JACK C. McCORMACK,
*  PAGE 383 EXAMPLE 22-5, PLANE FRAME WITH NO SIDESWAY
*  ANSWER - MAX BENDING = 44.4 FT-KIP
*
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 0 20 0; 3 20 20 0; 4 20 0 0;
MEMBER INCIDENCES
1 1 2; 2 2 3; 3 3 4;
MEMBER PROPERTY AMERICAN
1 TO 3 PRIS AX 1 IZ 0.05
DEFINE MATERIAL START
ISOTROPIC MATERIAL1
E 4.132e+06
POISSON 0.3
END DEFINE MATERIAL
CONSTANTS
MATERIAL MATERIAL1 ALL
SUPPORTS
1 4 FIXED
LOAD 1
MEMBER LOAD
2 UNI Y -2
PERFORM ANALYSIS
PRINT MEMBER FORCES
FINISH

STAAD Output

   MEMBER END FORCES    STRUCTURE TYPE = PLANE
   -----------------
   ALL UNITS ARE -- KIP  FEET     (LOCAL )
  MEMBER  LOAD  JT     AXIAL   SHEAR-Y  SHEAR-Z   TORSION     MOM-Y      MOM-Z
      1    1     1     20.00     -3.33     0.00      0.00      0.00     -22.21
                 2    -20.00      3.33     0.00      0.00      0.00     -44.44
      2    1     2      3.33     20.00     0.00      0.00      0.00      44.44
                 3     -3.33     20.00     0.00      0.00      0.00     -44.44
      3    1     3     20.00      3.33     0.00      0.00      0.00      44.44
                 4    -20.00     -3.33     0.00      0.00      0.00      22.21