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out-of-range velocities

out-of-range velocities

out-of-range velocities

(OP)
Dear all,

I'm simulating an impact test using ansys/ls-dyna, when I change an imput data  "out-of-range velocities" error appears: for example,since  I tried to insert the following soil  and gravity datas


N,300000 ,8000,0,50,,,,
N, 300001,8000,0,7000,,,,
N,300002 ,-17000,0,7000,,,,   
N,300003 ,-17000,0,50,,,,

EDMP,RIGI,5,7,7
MP,DENS,5,1.57e-7   
MP,EX,5,200e3   
MP,NUXY,5,0.33  




TYPE,   2   
MAT,       5
REAL,       1   
ESYS,       0   
SECNUM,
!*  
FLST,2,4,1  
FITEM,2,300001
FITEM,2,300000
FITEM,2,300003  
FITEM,2,300002
E,P51X  


ESEL,S, , ,   12248
NSLE,S  
CM,suolo,NODE   
NPLOT   
ALLSEL,ALL  

ASEL,S, , ,       1
NSLA,S,1
CM,surfsoil,NODE
NPLOT   
ALLSEL,ALL  



*DIM,TIME,ARRAY,2,1,1, , ,  
!*  
*SET,TIME(2,1,1) , 1
*DIM,gravity,ARRAY,2,1,1, , ,   
!*  
*SET,gravity(1,1,1) , -8820000  
*SET,gravity(2,1,1) , -8820000
!gravity

EDLOAD,ADD,RBFY,0,8,TIME,gravity, 0, , , , ,  


!contact


EDCGEN,STS,surfsoil,soil,0,0,0,0,0, , , , ,0,10000000,0,0

 

my model goes in instability:


"node #  ... has out-of-range velocities"



Is there a certain reason why instability appears?

I tried to semplify my model, but I obtained no results

Is there literature about this problem? Is it contained in ansys help?


Oh I forgot... if possible, I'd like to maintain initial velocity for impacting body (20-30 Km/h) , target body thickness and mat prop (steel, 5mm)


tnx to all for attention, regards

RE: out-of-range velocities

(OP)
Can it be a coarse mesh problem?

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