INCLINED COLUMN DES|GN 1

[malikasal]

GUYS I HAVE A PROJECT WITH INCLINED PARAMETER COLUMNS, AFTER MODELLING THE STRUCTURE USING RAM ELEMENT I NOTICED THAT THE COLUMNS DON'T TRANSFER THE AXIAL LOADS TO EACH OTHER I MEAN EVERY COLUMN CARRIES THE LOAD TAKEN FROM THE SLAB AND DOESN'T TAKE ANY LOAD FROM THE COLUMN ABOVE, I ASKED MY SUPERVISOR AND HE JUST ASSUMED THAT THIS IS THE ACTUAL CASE, BUT I AM NOT CONVINCED !!!. SO I AM HOPING THAT WE CAN DISCUSS THE BEHAVIOR OF THE INCLINED COLUMNS .

 

[CELinOttawa]

Please STOP YELLING.

What is the incline? IE: Is this more beam than column?

I cannot see why a column directly below another would not see the upper column's axial load (as well as a deal load due to the column directly above).

A sketch would help. Oh, and in general the behaviour of significantly inclided columns is as a beam-column (thus analysed both as a flexural element and a (slender, medium, stout) compressive member through a combined actions formula).

 

[JLNJ]

It sounds like there may be errors in your model. Serious errors.

 

[paddingtongreen]

There must be reaction points picking up the missing load, they cannot just disappear. Look at the deflection graphics, when exaggerated, they usually tells the story.

Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin

 

[malikasal]

CELinOttawa Thank you dude i will uppload a snapshot for the model when i get to the office .

JLNJ : I thought that first , and then i modelled a small structure just with four columns and it gave me the same results!!

on one side the columsn transfered the loads to each other and in the other side the load wasnt transfered!!1

I am using RAM ELEMENTS V 13 .

 

[RFreund]

Do your base reactions add up to the total load applied?
Make sure you are not applying support at the column joints.

EIT

http://www.HowToEngineer.com

 

[CELinOttawa]

Malikasal: You're doing the right thing by checking through the load paths, and finding this error is a major red flag!

I'm not much of a software guy, prefering my own spreadsheets and old fashioned graphics statics and hung loads for seismic. I have designed a stadium's stands this way, so you can do nearly anything that the computer can do... And you can see immediately when something doesn't look "right".

I can't help you debug your model, but I can give you a great tip for *how* to bebug your model: Create a table of the load values, live and dead, from the highest level on down. For each column work out what the tributary area would be, and run the loads down. If the computer says anything more than 20% different from this basic check (keeing in mind you need to track your loads for continuity accross supports and fixity at columns, etc) then the model is wrong.

 

[AELLC]

Be aware inclined columns create very large horizontal components at each floor and roof level.

 

[johnbridge231]

Moreover, their deformation capacity and thus plasticity are both limited.​

Analysis and Design of arbitrary cross sections
Reinforcement design to all major codes
Moment Curvature analysis

http://www.engissol.com/cross-section-analysis-design.html

 

[dtex]

Try Debugging your model....

Delete or Cancel out ALL of the loads in your model (as I'm guessing you have all member self weights, etc, and probably other loads applied also).

Then... place a single concentrated point load on your model at some location, such that it will be incredibly easy to follow the load path. Run your analysis again and see what you get. Does the answer make sense. If not, figure out what in your model... or your thinking... is off.

Dan

 

[malikasal]

Than you guys . That was so helpfull