Coilgun — Welcome to LS-DYNA Examples

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This example shows a coilgun simulation, also known as a Gauss rifle. It is a type of projectile accelerator consisting of one or more coils used as electromagnets in the configuration of a linear motor that accelerate a ferromagnetic or conducting projectile to high velocity. The EM solver is coupled to the Solid mechanics LS-DYNA solver.

Description

This example shows a Full 3-dimensional Eddy current Coilgun simulation. The Simulation is based on a symmetric monolithic FEM-BEM coupling (instead the classic Richardson a.ka weak FEM-BEM coupling used for metal forming applications). No airbox is needed. The computational model consists of the solid parts only. The projectile is made out of VACOFLUX 48. A Newton-Raphson method with linesearch is used to tackle the nonlinearity

Animated Result

EM magnetic field :

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Keywords

*CONTROL_TERMINATION
*CONTROL_TIMESTEP
*DATABASE_BINARY_D3PLOT
*DEFINE_CURVE_TITLE
*EM_CIRCUIT
*EM_CONTROL
*EM_CONTROL_COUPLING
*EM_CONTROL_TIMESTEP
*EM_MAT_001
*EM_MAT_002
*EM_OUTPUT
*EM_SOLVER_BEM
*EM_SOLVER_BEMMAT
*EM_SOLVER_FEM
*EM_SOLVER_FEMBEM_MONOLITHIC
*END
*KEYWORD
*MAT_RIGID
*PARAMETER
*PART
*SECTION_SOLID
*TITLE

Reduced Input

$-----------------------------------------------------------------------------
$
$ Example provided by Iñaki (LSTC)
$
$
$
$X------------------------------------------------------------------------------
$X
$X 1. Run file as is.
$X    Requires LS-DYNA MPP Dev dated Aug 2020 (or more recent) with double precision 
$X
$X------------------------------------------------------------------------------
$# UNITS: (kg/m/s) 
$X------------------------------------------------------------------------------
$X
$ ******************************************************************************
$
$ E L E C T R O M A G N E T I C   M A T E R I A L
$
$ ******************************************************************************
*EM_CONTROL
$--------1---------2---------3---------4---------5---------6---------7---------8
$#   emsol     numls        dt              
         1              &dt_em
*EM_CONTROL_COUPLING
                   2 
*EM_CONTROL_TIMESTEP
$--------1---------2---------3---------4---------5---------6---------7---------8
$#  tstype    dtcons      lcid    factor      
         1    &dt_em         0       1.0
*EM_SOLVER_FEM
$--------1---------2---------3---------4---------5---------6---------7---------8
$#  reltol    maxite     stype    precon   uselast  ncyclfem        
      1e-8     10000         1         1         1      
*EM_SOLVER_BEM
$--------1---------2---------3---------4---------5---------6---------7---------8
$#  reltol    maxite     stype    precon    uselas  ncyclbem        
     1.e-8     10000         2         2         1         
*DEFINE_CURVE
111
0,100
5.e-4,100
1.e-3,50
2.e-3,10
2.5e-3,5
3.e-3,2
5.e-3,2
*EM_SOLVER_FEMBEM
$--------1---------2---------3---------4---------5---------6---------7---------8
$   relTol   maxIter  forceCon alphaImpl solveType
     1.e-4        50                            
*EM_SOLVER_FEMBEM_MONOLITHIC
0,,1.e-8,1.e-8,10000
*EM_OUTPUT
$--------1---------2---------3---------4---------5---------6---------7---------8
$#    mats      matf      sols      solf      mesh       mem    timing      
         2         2         2         2         0         0         0         0
*EM_SOLVER_BEMMAT
$--------1---------2---------3---------4---------5---------6---------7---------8
         1                                                                 1.e-8
*EM_SOLVER_BEMMAT
         2                                                                 1.e-8
*EM_SOLVER_BEMMAT
         3                                                                 1.e-8
*EM_EOS_PERMEABILITY
$--------1---------2---------3---------4---------5---------6---------7---------8
$#   eosid   eostype      lcid    
       102         1       402
*EM_MAT_001
$--------1---------2---------3---------4---------5---------6---------7---------8
$#     mid     mtype     sigma     eosid
 &mid_coil         1
*EM_MAT_002
$--------1---------2---------3---------4---------5---------6---------7---------8
$#     mid     mtype     sigma     eosid     murel     eosmu
 &mid_proj         2    &sigma         0    &murel       102
*EM_CIRCUIT_SOURCE
$--------1---------2---------3---------4---------5---------6---------7---------8
$#  circid   circtyp      lcid       r/f       l/a      c/t0        v0  
         1         1       101
$# sidcurr    sidvin   sidvout    partid      
         3                             2
*END

Figures

 

coilgun.png

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