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Quasi-static Indentations FSI with RADIOSS

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I am trying to perform a quasi-static simulation using radioss. The initial model entailing solely hyper-elastic materials is working fine. Now I replaced a material type 42 with material type 37 that is a bi-phase material. My problem is that when enabling a mass scaling through /DT/NODA/CST in order to reduce the kinetic energy of the model and perform a quasistatic analysis, the model doesn't follow the requested time step. And then the solver stops due to negative volumes. Is there a way perform a quasistatic FSI with radioss? If so which are the appropriate values for MAT37? Is it better to choose a different material? or it isn't possible to perform such an analysis and thus move it to acusolve.


Here is my .hm file


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the mass scaling technique will not reduce the kinetic energy- to the contrary, it will increase by adding mass. The timestep imposed is too high, increasing the mass of the model by 380% (normally only 1-2% mass increase is feasible)- probably the run fails due to this. Check INITIAL ADDED MASS ESTIMATION  in the starter out file: at scale factor 0.9 for a 1% increase in mass the imposed timestep should be 1.174E-06 instead of 1E-4. 


Although I haven't found this in the Radioss manual, it looks like MAT 37 is not supported for mass scaling (mass scaling in your model applies to other components and interfaces).


Fluid-Structure Interaction Analysis with Radioss and AcuSolve is possible (check the attached document from Radioss manual).


There are initial penetrations in your model and should be cleared before running. 

Fluid-Structure Interaction Analysis with Radioss and AcuSolve.pdf

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 @Hyperman ty very much for your response. For a quasi static simulation with an explicit solver it is required mass increase but the balance is fragile between the added mass the solution time and the time step. But if mat 37 is not suited for such an application I probably move the analysis to optisturct acusolve coupling for a  DC-DFI.


Thx again

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