Hi friends,
I have to model the structure for foundation of machine. The structure is only beam column and I need to input the vibration of machine on top. I assumed the vibration is 30% of machine' weight (4 ton). And I devided by 4 because each machine are supported by 4 columns.
I have followed the example problem 16 but the resulted moment for beam is quite strange. The moment is not like a sagging and hogging.
************************************************************************************DEFINE TIME HISTORY DT 0.0013888TYPE 1 FORCE0 0 0.1 60 0.2 120 0.3 180 0.4 240 0.5 300 0.6 240 0.7 180 0.8 120 0.9 601 0TYPE 2 FORCE0 0 0.1 120 0.2 240 0.3 360 0.4 480 0.5 600 0.6 480 0.7 360 0.8 240 0.9 1201 0ARRIVAL TIME0
***********************************************************************************LOAD 1 LOADTYPE None TITLE DEADSELFWEIGHT Y -1 MEMBER LOAD9 11 13 15 18 22 25 29 31 33 35 37 64 TO 68 74 TO 78 83 TO 87 93 TO 97 181 -183 184 186 UNI GY -4.5711 13 21 28 33 35 69 TO 73 88 TO 92 182 185 UNI GY -4.32LOAD 2 LOADTYPE None TITLE LIFEELEMENT LOAD101 TO 180 PR GY -2.5LOAD 6 LOADTYPE None TITLE VIBSELFWEIGHT X 1 SELFWEIGHT Z 1 TIME LOAD2 8 10 16 18 24 26 32 FX 1 1 1.000000TIME LOAD4 6 12 14 20 22 28 30 FX 2 1 1.000000TIME LOAD2 8 10 16 18 24 26 32 FZ 1 1 1.000000TIME LOAD4 6 12 14 20 22 28 30 FZ 2 1 1.000000***********************************************************************************LOAD COMB 3 1.4D+VIB1 1.4 6 1.0 LOAD COMB 4 1.2D+1.6L+VIB1 1.2 2 1.6 6 1.0 LOAD COMB 5 D+L+VIB1 1.0 2 1.0 6 1.0 PERFORM ANALYSISDEFINE ENVELOPE3 4 ENVELOPE 1 TYPE STRESSEND DEFINE ENVELOPEFINISH
Do I have a correct assumption about this? Is there any command that I missed?
Please help me on this problem.
Thanks and Regards
Yusak