dytran案例15

WS14-2
Problem Description
● The effect of a blast wave on a structure will be simulated
using the graded mesh technique.
● If the distance between the explosive and target is large, then the
● Please refer „Blast Wave with a Graded Mesh, page 214‟
in Chapter 4, Fluid-structural Interaction from Examples Problems Manual.
DYT101, Workshop 14, February 2008 Copyright 2008 MSC.Software Corporation WS14-3
$ --- Material definitions --$ PEULER1,1,,MMHYDRO,19 $ DMAT,100,1,2 $ EOSGAM,2,1.4$ DYT101, Workshop 14, February 2008 Copyright 2008 MSC.Software Corporation
DYT101, Workshop 14, February 2008 Copyright 2008 MSC.Software Corporation
WS14-5
Step 1. Input File (Cont.)
SPC=1 $ TYPE (ALLEULER) = ARCHIVE ELEMENTS (ALLEULER) = 2 SET 2 = ALLMULTIEULHYDRO ELOUT (ALLEULER) = DENSITY,SIE,PRESSURE,XVEL,YVEL,ZVEL, FMAT,FVUNC STEPS(ALLEULER) = 0,thru,end,by,20 SAVE (ALLEULER) = 10000 $ TYPE (BOX) = ARCHIVE $------- Parameter Section -----PARAM,INISTEP,1.E-8 $
simulation takes a lot of CPU time. ● To run the simulation more efficiently, part of the fine mesh is replaced by a coarser mesh. The initial stage of the expansion takes place in a small fine mesh. This mesh is then glued to a larger mesh with coarser elements by using the graded mesh capability. ● The effect of a detonation on the environment can be simulated by assuming that the detonated material can be idealized by a sphere of hot gas with a homogenous density and specific internal energy. This approach is suited for problems in which the processes inside the explosive material are not investigated. The technique is called the “Blast Wave” approach.
PARAM,BULKL,0.1 $ PARAM,COSUBMAX,100 PARAM,COSUBCYC,100 $ PARAM,FASTCOUP PARAM,MICRO,30 PARAM,FMULTI,1.0 $ PARAM,GRADED-MESH
Glues fine meshes to coarse meshes.
This section of the Dytran input file describes the initial value sets for Eulerian regions which are defined by geometric shapes..
The coarse and fine meshes are created using Mesh entry.
WS14-4
Step 1. Input File
● Review the input file, gas.dat from Example Problems
Hale Waihona Puke under EP4_15.
START CEND ENDSTEP = 660 CHECK=NO TITLE= Blast wave Graded Mesh TIC=1 SPC=1 $ TYPE (ALLEULER) = ARCHIVE ELEMENTS (ALLEULER) = 2 SET 2 = ALLMULTIEULHYDRO ELOUT (ALLEULER) = DENSITY,SIE,PRESSURE,XVEL,YVEL,ZVEL, FMAT,FVUNC STEPS(ALLEULER) = 0,thru,end,by,20 SAVE (ALLEULER) = 10000 $ TYPE (BOX) = ARCHIVE CPLSURFS (BOX) = 3 SET 3 = 300 CPLSOUT (BOX) = PRESSURE,XVEL STEPS (BOX) = 0,thru,end,by,20 SAVE (BOX) = 10000 $ TYPE (LAG) = ARCHIVE ELEMENTS (LAG) = 4 SET 4 = ALLSHQUAD ELOUT (LAG) = EFFST-MID,EFFPL-MID STEPS (LAG) = 0,thru,end,by,20 SAVE (LAG) = 10000 $ TYPE (ARCMAT) = TIMEHIS MATS (ARCMAT) = 15 SET 15 = 100 MATOUT (ARCMAT) = EKIN,MASS,ZMOM,XMOM,YMOM STEPS (ARCMAT) = 0,THRU,END,BY,10 SAVE (ARCMAT) = 99999 $ $ $------- Parameter Section -----PARAM,INISTEP,1.E-8 $ $------- BULK DATA SECTION ------BEGIN BULK $ ============ Euler ================================== $ PARAM,BULKL,0.1 PARAM,COSUBMAX,100 PARAM,COSUBCYC,100 $ PARAM,FASTCOUP PARAM,MICRO,30 PARAM,FMULTI,1.0 $ PARAM,GRADED-MESH $ $ --- Material definitions --$ PEULER1,1,,MMHYDRO,19 $ DMAT,100,1,2 $ EOSGAM,2,1.4 $ --- Initial conditions --TICEUL,19,,,,,,,,+ +,SPHERE,3,100,8,4.0,,,,+ +,SPHERE,4,100,9,6.0 SPHERE,3,,0.0,0.0,0,10000 SPHERE,4,,1.125,0.0,7.5,1 TICVAL,8,,density,1,sie,3e+5 TICVAL,9,,density,1,sie,9e+5 $ MESH,1,BOX,,,,,,,+ +,-4.5,-0.18,0.0,18,0.36,15,,,+ +,48,1,30,,,,EULER,1 $ MESH,2,BOX,,,,,,,+ +,-1.5,-0.18,5,5.25,0.36,5,,,+ +,18,1,18,,,,EULER,1 $ $ --- Boundary conditions --------$ FLOWDEF,1,,MMHYDRO,,,,,,+ +,FLOW,OUT $ $ COUPLE,200,300,INSIDE,ON,ON, SURFACE,300,,PROP,5 SET1,5,5
$ --- Boundary conditions --------$ FLOWDEF,1,,MMHYDRO,,,,,,+ +,FLOW,OUT $ $ COUPLE,200,300,INSIDE,ON,ON, SURFACE,300,,PROP,5 SET1,5,5 $
● The material of the structure (box) is steel:
● Density = 7800 kg/m3
● Young‟s modulus = 2.1E+11 Pa ● Poison‟s ratio = 0.3 ● Yield Stress = 2.E+8 Pa
DYT101, Workshop 14, February 2008 Copyright 2008 MSC.Software Corporation
This section of the Dytran input file describes the Output requests.
This section of the Dytran input file describes the Initial Time Step of the simulation. Defines the default value of the linear bulk viscosity coefficient. Defines and controls the maximum number of subcycles that occur in Euler/Lagrange coupling.