An aluminum tube of 90-mm outer diameter is to carry a centric load of 120 kN. Knowing that the stock of tubes available for use are made of alloy 2014-T6 and with wall thicknesses in increments of 3 mm from 6 mm to 15 mm, determine the lightest tube that can be used.

9mm tube

Explanation:

Given data:

Outer diameter = 90-mm   therefore outer radius ( R ) = 90/2 = 45-mm

centric load = 120kN

wall thickness of tubes = 3mm from 6 mm to 15 mm

length of column = 2.25 m

Inner radius ( r )  = 45 - 6 = 39-mm

Determine the lightest tube to be used

we calculate the area of the column = 1.593 * 10^-3 m^2

next we determine the moment of Inertia = 1.4036 * 10^-6 m^4

determine radius of Gyration = 0.02977 m

slenderness ratio = 75.57

Allowable stress = 65.14

Allowable load = ( allowable stress * Area ) = (65.14 * 10^6 * 1.583 * 10^-3) = 103.12 kN

Attached below is a detailed solution

In order to make the right choice the given value Pall will be greater than 120Kn hence we will use 9mm thickness as the lightest tube

do you have any options?

answer:

i cant give me a pic

explanation: