FEA & STAAD.Pro

[hungrydinosaur]

Hi All,

I am doing an analysis in STAAD.Pro for a container. The container is modeled and lifted with four lifting slings. To stabilise the model, normally springs are used at the bottom in horizontal planes at the four corners. This is a 25 Metric Tonne container. There are 8 springs in total (2 on each corner).
The container becomes stable when I give a stiffness of 100 kN/m to each spring. Is there any rule of thumb on what should be a reasonable value of spring stiffness for each spring at the corner?

Regards,

HD

 

[jayrod12]

What are the real life conditions you are trying to model? If you need stability in the model then in theory you should need it in real life, how is it being provided?

 

[JoshPlumSE]

I look at it as what would be reasonable force for a worker to use when guiding the object during a lift. That way, you can give your results a reality check.

If you're getting lots of deflection, require a very stiff spring, or require a lot of force at each point, then doing a 1st order static analysis on the lift may not be appropriate.