Bogdan Mateescu IMSAT SA

Buna ziua,

As avea o intrebare despre modelizarea elementelor de tip tirant. Aceste elemente nu ar trebui sa aiba inertie 0 la compresiune?

 

Bogdan MATEESCU

I have a problem that i don't know how to explain
I modelised a structure like in the picture attached and i defined different cases of loadings.
loads from wind, seismic loads and permanent loads.
in 2 similar combination of loads i changed the sign for the horizontal loads
E.g.: 1) 1x[horizontal loads]+1x[vertical loads]+1x[wind loads]
         2) 1x[horizontal loads]-1x[vertical loads]+1x[wind loads]
when i run the analysis in the case no. 2) i obtained at the bottom of the pole in the rigid fixing point  a positive vertical effort.
After that, i changed and i replaced the weight of the element by vertical efforts bottom oriented. When i run the analysis i obtain the same value for the vertical effort at the bottom of the pole, which i consider normal.
can anyone explain to me what is happening actually



modification : it was an error at my post. The correct version is like that
E.g.: 1) 1x[horizontal loads]+1x[vertical loads]+1x[wind loads]
         2) -1x[horizontal loads]+1x[vertical loads]+1x[wind loads]

I have a problem that i don't know how to explain
I modelised a structure like in the picture attached and i defined different cases of loadings.
loads from wind, seismic loads and permanent loads.
in 2 similar combination of loads i changed the sign for the horizontal loads
E.g.: 1) 1x[horizontal loads]+1x[vertical loads]+1x[wind loads]
         2) 1x[horizontal loads]-1x[vertical loads]+1x[wind loads]
when i run the analysis in the case no. 2) i obtained at the bottom of the pole in the rigid fixing point  a positive vertical effort.
After that, i changed and i replaced the weight of the element by vertical efforts bottom oriented. When i run the analysis i obtain the same value for the vertical effort at the bottom of the pole, which i consider normal.
can anyone explain to me what is happening actually

Attachment: 1_2.bmp

thank you for your answer. I figured out what i did wrong.
it was an another element in my structure which was defined as a cable (the pole - my mistake) :) and i didn't saw it. Now it works fine. i was able to obtain the result that i was looking for.
your answer was instructive though, thank you

i modelised the structure in the image attached. the beam that you see there is attached to that pole by a cable.
when i analyse the structure i receive the next message "vous avez maille des elements modelise en cable" (i have the french version of advance design). at the cables properties panel  for the "maillage" section i have unchecked the "automatic maillage" and at the parameters  i have put "1" at number so that it will be a single piece.
what have i did wrong and what should i do so that it works?

Attachment: 1_0.bmp