Learning Forum

[jhon9]

Hello. im try to simulate polymer by sph method in ls dyana. but the error about material type 102 is not implemented is accourd. Where the bug might be? ls dyna can solve this type of mat by sph method ? i have private data and temperature dependent viscosity for my polymer and i also have stress&strain temperature dependent data for my polymer. what mat i must use for sph method?n quit ls-dyna terminates.n stop ls-dyna terminates.n sw1. a restart file is written and ls-dyna terminates.n sw2. ls-dyna responds with time and cycle numbers. n sw3. a restart file is written and ls-dyna continues calculations.n sw4. a plot state is written and ls-dyna continues calculations.n lpri toggle implicit lin. alg. solver output on/off.n nlpr toggle implicit nonlinear solver output on/off.n iter toggle implicit output to d3iter database on/off.n prof output timing data to messag and continue.n conv force implicit nonlinear convergence for current time step.n ttrm terminate implicit time step, reduce time step, retry time step.n rtrm terminate implicit at end of current time step.nnError 30281 (INI+281)n SPH initializationn Material number 3n material type 102 is not implementednn

[ramgopisetti]

Based on your information, I came into conclusion as followsnFirst Thing, MAT102/MAT_INV_HYPERBOLIC_SIN_{OPTIONAL} is not supported by SPH element. Please check the followign link for supported SPH formulations.nBased on the Material properties that are defined in above comment, like nTemperature Vs Viscosity ----> Looks more like a Fluid Formulation. nStress Vs Strain as function of Temperature nThis is supported in MAT_106[MT_ELASTIC_VISCOPLASTIC_THERMAL] but the Temperature VS Viscosity is to be modelled as Harding (Isotropic and Kinematic) Coefficients, That said, the flowablity of the material ,mainly plastics, is defined by how soft they are for their respective temperatures so why not model them as function of VISCOELASTIC terms.nAlternative solution,nIf you remove the constriaints of SPH, you can unlock more straight forward material cards which will directly support your data natively, for the hot plastics use the following Material Cardsn*MAT_60 (*MAT_ELASTIC_WITH_VISCOSITY)-------********The Best Solution********nn*MAT_106 (*MAT_ELASTIC_VISCOPLASTIC_THERMAL)nComment down your response for futher support.nAll the best, Cheers,nRamn

[jhon9]

thank you. my polymer properties is something like picture below. also i build Eos linear polynomial model for simulation. ncan i combine this data in one mat ? (my simulation start in room temperature an it goes up over 500 k). my problem is about material flow. and im solved in fluent. but i want use sph method for better result in simulation. nbest regards.n

[ramgopisetti]

Can you elaborate your study like what are you trying to find out and implement. SPH also support MAT_NULL which has Density , Dynamic Viscosity at room temperature , Pressure cut-off and this model needs EOS, more like an fluid type . This is one such approach to workaround the your problem. Can u able to show an instance of the results for better assistance. nCheers, nRamn

[jhon9]

hello . im research about friction stir welding material flow. i want to give some output like below from sph method.nthy use jhonson cook mat. but i dont have failure parameter(d) how to buld d1 to d5 ? simple curve fit or something else ?nbest regards.n

[ramgopisetti]

finally you need to model the FSW using SPH, Can you able to specify the process conditions and what version of LSDYNA do you have so i can upload you an form of solved file to run in your lsdynan