Containers Get Beat Up.
Like a rookie MMA fighter, shipping containers take a serious beating. It’s normally not much of a concern, except when you have to ship something hazardous. This is where the design of specialty containers comes in. When these containers are being designed, they need to be either tested, or an impact analysis needs to be done to make sure the containers will survive the beating.
Test & Design Requirements
The options are simple. Test or Analyze. Testing containers is fun, but there are drawbacks:
- Very Expensive
- Dangerous
- Damages Equipment
- Unable to determine margin
Analysis doesn’t have these drawbacks, so it’s the obvious choice, specifically, Finite Element Analysis.
FEA can be used to actually see stresses in shipping containers. Since you’re able to see the stresses, it means that the designer can iterate on the design, each time cutting down on the peak stress. This is a key benefit to using FEA. When you do a drop test, you can’t see margin, but with FEA, you can!
Design Example
We looked at a simple shipping container for a horizontal tank (industry name tanktainer). Inside this tank could be any hazardous material, and damage could spell disaster. First, we looked at a simple static problem, lifting the tank from the top. You can see that the tank saddles are loading the frame, causing some localized stresses (red).
Next, we looked at dropping the container. For this tank, one of the worst cases would be a drop on the corner. Below, you can see the drop again caused some localized stresses near the saddle, but there are also stresses in the vertical support.
More Information: Design and Testing Requirements of Robust Shipping Containers
If you’re interested in reading more about shipping containers, here are a few good sources of information.
