
#1
Aug113, 05:23 PM


#2
Aug213, 04:01 PM

Sci Advisor
HW Helper
P: 2,110

sudnak: Ensure d2/t does not exceed 40, and then your steel pipe will not flexurally buckle, where d2 = pipe outside diameter (OD), and t = pipe wall thickness.
Yes, compute moment of inertia (I). Also compute bending moment (M) on the pipe at the cable. Then compute sigma = M*c/I. Ensure sigma does not exceed 170 MPa. Because you have the cable tensile force, you can compute bending moment M, but you will need the distance from the pivot to the cable attach point, the distance from the pivot to the mass, the mass of the mass, and the angle between a vertical line and the pipe when the cable tensile force is 2800 N. 



#3
Aug213, 06:27 PM

P: 3

What is c in your M*c/I?




#4
Aug213, 10:17 PM

HW Helper
Thanks
P: 5,542

Calculating buckling strength of steel pipe for nonaxial load
c = OD/2, where OD is outside diameter of the pipe.




#5
Aug213, 10:25 PM

HW Helper
Thanks
P: 5,542

You haven't specified the type of piping material or grade you are using. For ordinary pipe material, the maximum tensile strength is lower than that for ordinary steel (30 ksi for Grade A pipe v 36 ksi for ASTM A36 steel). I would limit the max. bending stress to 120125 MPa (18 ksi) to give yourself a reasonable factor of safety.




#6
Aug213, 10:57 PM

P: 3

Awesome, thank you so much for the recommendations, I cannot tell you how much it helps!




#7
Aug813, 09:14 AM

P: 2

Hi, i have some annotations:
 In this case, the kind of stress is bending, not buckling.  I recommend you to consult the "Specification for Structural Steel Buildings (ANSI/AISC 36010)": http://www.aisc.org/WorkArea/showcontent.aspx?id=26516 (go to F.8 chapter). 



#8
Aug913, 09:18 AM

Sci Advisor
HW Helper
P: 2,110

mauchitoq: No, sudnak is correctly referring to flexural buckling, as well as bending stress. This was covered in post 2. Recheck, e.g., the subject title of the thread.




#9
Aug913, 11:18 AM

P: 2

nvn: it's true. But in steel structural engineering, buckling usually is about the behavior explained with Euler formula, and not with the stress failure criteria.



Register to reply 
Related Discussions  
Cylindre buckling under axial load  Mechanical Engineering  6  
axial load strength of PVC pipe  Mechanical Engineering  5  
Minimum strength of pipe for load bearing  General Engineering  1  
what size square mild steel pipe will support load  Mechanical Engineering  4  
slenderness ratio and axial load of steel question..pls help  Mechanical Engineering  9 