Multi Section Columns 1

[Allen]

Hi All

Is there or anybody knows any formula/reference for analysis a multi section slender column buckling? or finite element is the only solution?

e.g. a column made up of two rod sections, one phi=60mm and the other phi=100mm ( with the same material ) welded at ends. or a phi=100mm connected with a pipe and loaded axially.

I searched in my books and the web but nothing found.

Cheers

 

[trainguy]

Try Roark's formulas for stress & strain. There are effective slenderness ratios & lengths you can use.

Alternatively, the Design of Aluminum (Alcan, 1983) handbook has some expressions as well.

tg

 

[Allen]

Thanks alot trainguy,

Our office doesn't have those books, but I will try to find them in a liberary or somewhere else.

 

[JStephen]

Possibly just design using the more flexible of the two.

 

[Allen]

Possibly just design using the more flexible of the two.

We can not, because, the first portion is a fixed diameter and the entire length is fixed also, so the only design unknown is the second portion section which should be a pipe.

 

[rb1957]

i think you can still use the smaller section ... one section of the column is (by the sound of it) a solid bar, and the other is a tube, ok ?

then assume the tube is the full length of the column, and use euler, or euler-johnson, or whatever you prefer for a column buckling calc. this is going to be conservative.