What type of Analysis?

[ctassi1]

I will soon be analyzing a pump baseplate that will be pinned within a steel module at the 4 corners. The module will be shipped without the pump and motor attached, they will be attached later. When the module is lifted/lowered, forces and displacements will be experienced at the pin locations of the plate. There is concern that permanent deformation will be experienced due to these loads, and the pump performace could be affected.

The baseplates do have half symmetry, but the loading at the 4 corners are not symmetrical. The only BC's are at the 4 pinned corners where the forces and displacements are experienced.

My questions are how could I model this in linear static, should I use MES with prescribed displacements at the 4 pin locations, or is their another recommended way?

Thanks in advance!!

 

[GBor]

If the 4 corners are asymmetrically loaded, you will have to model the entire plate. I'm a bit confused on the "4 pinned corners where the forces and displacements are experienced". If you are saying that these are the "lift points" and the load is the baseplate self-weight, you should be able to apply some static g factor on the weight (like 1.3...depends on how slowly you are lifting), pin the corners as you suggest, and run the static analysis. See if the stresses are beyond yield. If so, you may have a problem. If not, you should be OK.

I wouldn't think an MES would be necessary regardless. If you are willing to allow some permenant deformation, but want to know just how much you should experience, a non-linear static should be acceptable unless you are looking for actual inertial loads...then the MES may be required.

 

[ctassi1]

Im sorry, I was a little vague on my description.

The pump base plate will be temporarily mounted in a 20'x40'x20' steel framed module. This module will house all piping components for the pump (valves, flanges, pipe, ect.) but will not be connectd to the pump nozzle. The base plates will be supported by two temporary steel beams spanning the width of the module. The base plates will be bolted at all 4 corners to these two temporary steel beams. During lifting of these modules, by crane to be installed in the refinery, I have the forces, moments and displacements that will be experienced at the 4 corners of the baseplate. The speed at which it is lifted or lowered shouldnt be a problem since it will be done slowely by crane.

Once the module is installed the temporary steel will be removed and the plate will be bolted to the pedestal it was lowered onto. There is concern that during this lifting/lowering the base plate may exceed yield and contain some permanent deformation affecting the performace of the pump.

The base plates are half symmetrical, but im unsure how I can restrain the plate in a linear static analysis and apply the necessary forces and moments. Or is an MES needed with the diplacements at 4 corners?

Im working on the cad file now, I can attach later if this is still confusing/unclear.

Thanks

 

[GBor]

Based on what you are saying, it looks like a fairly straight forward linear analysis. I would think you could model the beams under the plate as either plate elements or beam elements, pin the nodes that are held by the cables, place a "block" representing the pump, piping, etc. and attach it to the plate in a fashion similar to reality, place a gravity load on it with a "safety factor" for a load multiplier and see what you get, but send the CAD file and let's have a look.