Simplified Calculations for Nylon66 Composite Material Supporting Heavy Loads

[NNM]

TL;DR

Seeking guidance on manually calculating composite material performance for a Nylon66 structure supporting heavy loads. The box, intended for intermediate storage, will withstand approximately 30,000 N of force, primarily in the Y-direction, with support along the X-direction. Dimensions include 15mm for outer walls and 5mm for ribs. Assistance with simplified calculations and considerations for buckling, bulging, moment, von Mises stress, etc., is appreciated

I've conducted Finite Element Analysis (FEA) tests but have limited experience with composite materials. I need guidance on what calculations to perform manually, as my FEA results yield very small values.

Specifically, I need advice on how to approach analyzing a box filled with ribs. What calculations should I prioritize? The box is intended to support a pipe with a weight of approximately 480 kg per meter in smaller increments at a time, acting as a sort of intermediate storage. Thus, it will be subjected to roughly 30,000 N of total force, with forces primarily in the Y-direction and support along the side walls in the X-direction due to high friction, assuming it's stationary (fixed).

The material I've chosen is Nylon66, as in Inventor, with dimensions of 15mm for the outer walls and upper section, and 5mm for the ribs. I'm also considering simplified calculations where appropriate. Any tips on confirming these calculations? Considerations for buckling, bulging, moment, von Mises stresses, etc.?

Appreciate any help I can get.

 

[jrmichler]

Specifically, I need advice on how to approach analyzing a box filled with ribs.

Your question raises a few questions. You mention composite materials and Nylon 66. Which is it? Is it a fiber reinforced Nylon 66 or pure Nylon? If pure Nylon, that's a plastic, not a composite.

You mention friction, or are you trying to say that the sides are confined? Friction is very difficult to model properly, while confining the sides is easy to model.

Detailed manual calculations of your structure are unrealistic. The realistic manual calculation is a simple P/A for the portion of the structure that is in contact with the pipe, combined with a sufficient safety factor. Your Image 1 shows a structure with a saddle for the pipe, while your Image 4 shows a simple rectangular block structure. Which is it? Is the pipe laying flat on the structure, or is it at an angle as indicated in your Image 2?

What is the criteria for a good design? Is it a failure if the structure deflects elastically by 0.01 mm, or is it a failure only if it collapses completely?

 

[Lnewqban]

Being pipes, they may be carrying fluids at relative high velocities, which induce strong lateral forces on any support when pipes are changing direction and dilatating-contracting under changes of temperature.
Please, consider that additional load for designing anchoring of the blocks to either pipes or ground, footings, etc.

 

[NNM]

Your question raises a few questions. You mention composite materials and Nylon 66. Which is it? Is it a fiber reinforced Nylon 66 or pure Nylon? If pure Nylon, that's a plastic, not a composite.

You mention friction, or are you trying to say that the sides are confined? Friction is very difficult to model properly, while confining the sides is easy to model.

Detailed manual calculations of your structure are unrealistic. The realistic manual calculation is a simple P/A for the portion of the structure that is in contact with the pipe, combined with a sufficient safety factor. Your Image 1 shows a structure with a saddle for the pipe, while your Image 4 shows a simple rectangular block structure. Which is it? Is the pipe laying flat on the structure, or is it at an angle as indicated in your Image 2?

What is the criteria for a good design? Is it a failure if the structure deflects elastically by 0.01 mm, or is it a failure only if it collapses completely?

The idea is that the construction should indeed be rounded to achieve an evenly distributed load. The images are somewhat unrealistic in terms of the lengths of the pipes. The product is intended to hold the pipes for only up to 1 minute during the movement of pipes in production. Therefore, the product is only meant to hold the pipe at a certain height to attach another tool before moving. The material is somewhat uncertain, but fiber-reinforced Nylon 6 is being considered, as well as regular Nylon. PP is also being considered. In a simple P/A calculation, is it the cross-sectional area of a region, or the full area of the structure of the delimited region? The criterion is that it should be able to operate and minimize the time used to move the pipe, so if it bends elastically, it doesn't matter much as long as it doesn't collapse for safety reasons