Correct constraints for stress analysis of a frame supported by four floats in floating condition.

[M_BHATTA]

Stress analysis of a frame (includes parts not generated by frame generator) which four legs are supported by four floats and in floating condition (waves, wind, etc. external factors are assumed to be negligent at this phase, please suggest a constraint method to find the correct results. I tried to fix one leg and rest 3 frictionless constraints as they are floats. But the deformation is too large on adjacent leg of fixed leg. can anyone suggest the right constraint method for this. we have loads acting at center to lift the pump, weight of floats and buoyant force from float at each leg.

[johnsonshiue]

Hi! Typically, either Fixed or Pinned constraint is used.

Many thanks!

[blair]

I generally will fix one leg in XYZ and then pin support the other 3 legs. Goes back to the old days of using Algor which is now Simulation Mechanical since Autodesk bought them. 

[Frederick_Law]

Or fix where the load is.

Put upward load (1/4 of (pump weight + frame weight)) on the floats/legs and see how legs stretch.

[M_BHATTA]

@Frederick_Law I have used Buoyant force 1/4 of total load. fixing where the load does not give any deformation on the fixed part area. which is unlikely happen in practical. 

[M_BHATTA]

do you mean fixing all legs? float may displace horizontally in x,y direction upon act of load. float provides enough buoyant force to float so my assumption is it won't displace vertically. don't have proper cylindrical part to apply pinned constraint.

[M_BHATTA]

I normally fix the one leg and put frictionless constraint to other. didnt give appropriate results. as you suggested if pin constraint used to rest legs what type of pin constraint do you mean, fix axial, longitudinal, or tangential?