Dimensioning of hollow square and circular rod

AI Thread Summary
To determine the dimensions of square and circular hollow rods for a telescopic assembly, the load type—whether axial compression, tension, torque, or sideways deflection—must be considered. The design must balance outer dimensions and wall thickness while accounting for applied loads, including compression and bending. The specific application involves supporting a boat in a rack, factoring in both the boat's weight and wind forces. For a rod length of 2.26 m, suggested dimensions for the circular rod include options ranging from 155 mm outer diameter with 10 mm wall thickness to 216 mm with 5 mm thickness. Proper dimensioning is crucial for ensuring structural integrity and safety.
JohnnyR
Messages
3
Reaction score
0
Hi

Can someone tell me how to determine dimensions for a square hollow rod and circular hollow rod when the material and maximum load is known?
 
Engineering news on Phys.org
This will depend on the way the load is applied to the hollow member.
Is it axial compression or tension, torque or a sideways deflection ?
There is also a trade-off between outer dimension and wall thickness.
 
The applied load is compression and there is also bending.
It´s a telescopic rod with the circular rod inside the square rod and it´s standing vertically with an angle. The rod has to support a boat standing in a boat rack so it has to support the weight of the boat and the force from wind gust. The material is set to be S235JR Low Carbon Steel.
I hope you can help. Thanks.

http://imagizer.imageshack.us/v2/1024x768q90/833/drpm.jpg
 
Last edited by a moderator:
JohnnyR: If the length of your telescopic rod assembly is 2,26 m, and if your member forces in post 3 are correct, then it currently appears the round tube would need to have cross-sectional dimensions (outside diameter by wall thickness) as listed in any of the following options.

(1) 216 x 5 mm
(2) 197 x 6
(3) 182 x 7
(4) 171 x 8
(5) 155 x 10​
 
Last edited:

Thread 'Race car suspension Class'

Posted June 2024 - 15 years after starting this class. I have learned a whole lot. To get to the short course on making your stock car, late model, hobby stock E-mod handle, look at the index below. Read all posts on Roll Center, Jacking effect and Why does car drive straight to the wall when I gas it? Also read You really have two race cars. This will cover 90% of problems you have. Simply put, the car pushes going in and is loose coming out. You do not have enuff downforce on the right...
View full post »
Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'

Thread 'Physics of Stretch: What pressure does a band apply on a cylinder?'

Scenario 1 (figure 1) A continuous loop of elastic material is stretched around two metal bars. The top bar is attached to a load cell that reads force. The lower bar can be moved downwards to stretch the elastic material. The lower bar is moved downwards until the two bars are 1190mm apart, stretching the elastic material. The bars are 5mm thick, so the total internal loop length is 1200mm (1190mm + 5mm + 5mm). At this level of stretch, the load cell reads 45N tensile force. Key numbers...
View full post »

Thread 'Cantilever help'

I'm trying to decide what size and type of galvanized steel I need for 2 cantilever extensions. The cantilever is 5 ft. The space between the two cantilever arms is a 17 ft Gap the center 7 ft of the 17 ft Gap we'll need to Bear approximately 17,000 lb spread evenly from the front of the cantilever to the back of the cantilever over 5 ft. I will put support beams across these cantilever arms to support the load evenly
View full post »

Similar threads

B Vertical Compression Strength of Different Hollow Rods
Replies
24
Views
2K
Stronger or Stiffer? Tube vs Rod: Answers Here!
Replies
2
Views
2K
Maximum combustion chamber pressure and connector rod length
Replies
12
Views
1K
Can you me understand this mechanism?
Replies
5
Views
2K
How to calculate the weight of a submerged hollow cylinder?
Replies
3
Views
4K
Question about the mechanism of a fishing rod
Replies
7
Views
2K
Calculating Max Pull for M30x2mm Threads on Chrome Rod
Replies
7
Views
2K
Panel Structure vs. Solid Rod Structure
Replies
2
Views
2K
How Can Innovative Wheelchairs and Mobility Solutions Meet Client Needs?
Replies
23
Views
2K
Calculating Where to Push to Straighten a Rod
Replies
5
Views
3K

Hot Threads

Recent Insights

Back
Top