I'm new to STAAD and attempting to model a simple roof frame for a 1-story home with a tie beam. For some reason I am getting exceptionally large displacements (52") even though my loading is pretty light (dead, snow, wind) total of ~100plf max.
Of note: The furthest out supports are the walls w/ a 1' overhang. The inner two supports are "girders" going in the Z-direction which the rafters will be notched and attached too.
Here is my command file:
STAAD SPACESTART JOB INFORMATIONJOB NAME PSU ProjectJOB CLIENT PSUJOB REV 0ENGINEER NAME Hunter BrooksENGINEER DATE 8/21/2023END JOB INFORMATIONINPUT WIDTH 79UNIT INCHES KIPJOINT COORDINATES1 408 0 0; 2 180 38 0; 3 0 -37 0; 4 396 2 0; 5 12 -32 0; 6 318 15 0;7 124.8 15 0; 8 93.25 1.854 0; 9 340.75 11.208 0;MEMBER INCIDENCES1 1 4; 2 2 7; 3 4 9; 4 5 3; 5 6 2; 6 7 8; 7 7 6; 8 8 5; 9 9 6;DEFINE PMEMBER2 6 8 4 PMEMBER 11 3 9 5 PMEMBER 2SUPPORTS4 5 8 9 PINNEDUNIT INCHES POUNDDEFINE MATERIAL STARTISOTROPIC TIMBERE 1.5e+06POISSON 0.15DENSITY 0.0144676ALPHA 3e-06DAMP 0.06G 652174TYPE TIMBERISOTROPIC DFLE 1600POISSON 0.15DENSITY 0.01806ALPHA 3e-06DAMP 0.06G 652174TYPE TIMBEREND DEFINE MATERIALMEMBER PROPERTY1 TO 6 8 9 PRIS YD 9.25 ZD 1.57 PRIS YD 3.5 ZD 1.5CONSTANTSMATERIAL DFL ALLMEMBER RELEASE7 END MX MY MZ7 START MX MY MZDEFINE REFERENCE LOADSLOAD R1 LOADTYPE Dead TITLE DEADLOAD R2 LOADTYPE Snow TITLE SNOWLOAD R3 LOADTYPE Wind TITLE WINDEND DEFINE REFERENCE LOADSLOAD 1 LOADTYPE Dead TITLE DEADPMEMBER LOAD1 UNI GY -22 UNI GY -1.167LOAD 2 LOADTYPE Snow TITLE SNOWPMEMBER LOAD1 2 UNI GY -3.333LOAD 3 LOADTYPE Wind TITLE WINDPMEMBER LOAD1 2 UNI GY -3.133LOAD COMB 4 D+S1 1.0 2 1.0 LOAD COMB 5 D+.75S+.45W1 1.0 2 1.0 3 1.0 PERFORM ANALYSISDEFINE ENVELOPE4 ENVELOPE 15 ENVELOPE 2END DEFINE ENVELOPEFINISH
Any help would be appreciated! Thanks!
No solution here yet. I did end up changing the beam fixity at the ridge to pinned connections instead of how I accidentally had it as fixed but the deflection issue was still present. Guessing something is very off in terms of supports/stability but I have been unable to figure it out.
Young's modulus (E value) in your created material is off by 1000 I think. Increase the value by 1000 and the results should become more reasonable.