How can I calculate the bending moment of a pin in double shear?

AI Thread Summary
The discussion centers on calculating the bending moment of a pin in double shear under the load of a hydraulic cylinder. One participant suggests using pre-engineered clevis systems designed by manufacturers for optimal load handling. However, another contributor highlights the need for custom-engineered solutions due to specific requirements, such as high force and unique material needs for offshore applications. They emphasize the importance of consulting hydraulic manufacturers for tailored options rather than attempting to design custom mountings independently. The conversation concludes with an acknowledgment of the need for further research and manufacturer consultation.
itsBart
Messages
3
Reaction score
2
TL;DR Summary
I'm trying to calculate the diameter required for a pin in double shear, but I'm having a brain fart for the calculation of the bending moment.
I have attached an Excel-worksheet in which the problem should be clearified. The problem concerns the calculation of the bending moment acting in a pin in double shear, experiencing a certain load from a hydraulic cylinder. The plate thicknesses should be taken into account. Specifications and material properties are visible inside the Excel file.
Thanks in advance for any assistance.
 

Attachments

Engineering news on Phys.org
There is an easier way. Hydraulic cylinder end fittings and pins are designed by the cylinder manufacturer for the loads from the cylinder. Buy a cylinder with a clevis end and the matching clevis fitting and pin, then you will have an engineered system designed for any load that the cylinder can apply.
 
jrmichler said:
There is an easier way. Hydraulic cylinder end fittings and pins are designed by the cylinder manufacturer for the loads from the cylinder. Buy a cylinder with a clevis end and the matching clevis fitting and pin, then you will have an engineered system designed for any load that the cylinder can apply.

Thank you for your answer.
I think you have a viable solution for simple designs indeed. In my case though, I'm looking at multiple cylinders with a bore of 200 mm applying almost 500 kN of force used for the rotation of a big platform. This requires bearings and possibly less customary pin material such as duplex (1.4462) or such, which arenot included in the cylinder options. At least our customary supplier does not offer them (or any clevis design for that matter). I don't think clevis systems come with the bearings required for the product, which in turn will differ in size and properties depending on the environment (off-shore, in my case).
In short: I'm pretty sure I need a custom engineered system contrary to a pre-engineered clevis system (my apologies if you disagree).
 
I took a quick look at the Parker hydraulic cylinder catalog. They have catalog options for underwater use to 5000 feet depth. That's salt water, so their anticorrosion options should be good for offshore above water use.

Your force and cylinder bore require a pressure of "only" 2300 PSI, which is well below the 3000 PSI rating of Parker cylinders. Parker is not the only manufacturer of top quality hydraulic cylinders, just the one that I have had experience with.

You may need to look at other hydraulic cylinder manufacturers. I suggest contacting the hydraulic manufacturer directly before designing your own cylinder mountings. Designing your own mountings should be an absolute last resort.
 
  • Like
Likes itsBart
jrmichler said:
I took a quick look at the Parker hydraulic cylinder catalog. They have catalog options for underwater use to 5000 feet depth. That's salt water, so their anticorrosion options should be good for offshore above water use.

Your force and cylinder bore require a pressure of "only" 2300 PSI, which is well below the 3000 PSI rating of Parker cylinders. Parker is not the only manufacturer of top quality hydraulic cylinders, just the one that I have had experience with.

You may need to look at other hydraulic cylinder manufacturers. I suggest contacting the hydraulic manufacturer directly before designing your own cylinder mountings. Designing your own mountings should be an absolute last resort.

Alright, I think you're right. I started off with my project without much in-depth knowledge about cylinders, so my apologies for not looking into it sufficiently. I will contact the hydraulic manfucturer(s). Thank you for your help.
 
  • Like
Likes jrmichler and Tom.G
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...
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
Thread 'What's the most likely cause for this carbon seal crack?'
We have a molded carbon graphite seal that is used in an inline axial piston, variable displacement hydraulic pump. One of our customers reported that, when using the “A” parts in the past, they only needed to replace them due to normal wear. However, after switching to our parts, the replacement cycle seems to be much shorter due to “broken” or “cracked” failures. This issue was identified after hydraulic fluid leakage was observed. According to their records, the same problem has occurred...
Back
Top