Intermediate : Wave Impact on Elastic structure — Welcome to LS-DYNA Examples

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A water column collapses and impacts an elastic structure. This is a frequently used validation problem for which no experimental results were found. It uses mesh adaptivity to reduce the size of the mesh is zones were few flow features needs to be captured in order to save calculation tim

Animated Result

Fluid pressure fringes

dam

 

 

Keywords

*KEYWORD
*TITLE
*BOUNDARY_SPC_SET_BIRTH_DEATH
*CONTROL_IMPLICIT_DYNAMICS
*CONTROL_IMPLICIT_GENERAL
*CONTROL_IMPLICIT_SOLUTION
*CONTROL_TERMINATION
*DATABASE_BINARY_D3PLOT
*DATABASE_HISTORY_NODE
*DATABASE_NODOUT
*DEFINE_CURVE_TITLE
*DEFINE_FUNCTION
*ELEMENT_SHELL
*ICFD_BOUNDARY_FREESLIP
*ICFD_BOUNDARY_FSI
*ICFD_BOUNDARY_NONSLIP
*ICFD_CONTROL_ADAPT
*ICFD_CONTROL_FSI
*ICFD_CONTROL_OUTPUT
*ICFD_CONTROL_TIME
*ICFD_DATABASE_DRAG
*ICFD_MAT
*ICFD_PART
*ICFD_PART_VOL
*ICFD_SECTION
*INCLUDE
*INITIAL_VELOCITY_RIGID_BODY
*LOAD_BODY_Y
*MAT_ELASTIC
*MESH_INTERF
*MESH_SURFACE_ELEMENT
*MESH_SURFACE_NODE
*MESH_VOLUME
*NODE
*PARAMETER
*PART
*SECTION_SHELL
*SET_NODE_LIST
*END

Reduced Input

$-----------------------------------------------------------------------------
$
$ Example provided by Iñaki (LSTC)
$
$ E-Mail: info@dynamore.de
$ Web: http://www.dynamore.de
$
$ Copyright, 2015 DYNAmore GmbH
$ Copying for non-commercial usage allowed if
$ copy bears this notice completely.
$
$X------------------------------------------------------------------------------
$X
$X 1. Run file as is.
$X    Requires LS-DYNA MPP R9 (or higher) with double precision 
$X
$X------------------------------------------------------------------------------
$# UNITS: (kg/m/s) 
$X------------------------------------------------------------------------------
$X
*KEYWORD
*TITLE
ICFD Impact on hypoelastic structure
*INCLUDE
mesh.k
*INCLUDE
struc.k
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$                                                                              $
$                             PARAMETERS                                       $
$                                                                              $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*PARAMETER
R    T_end         2
R  dt_plot      5e-3
$
$--- Fluid
$
Rrho_fluid      1000
R mu_fluid     0.001 
R dt_fluid      1e-3
R  grav         9.81
R  fsi_bt        0.1
$
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$                                                                              $
$                           ICFD CONTROL CARDS                                 $
$                                                                              $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*ICFD_CONTROL_TIME
$#     ttm        dt
    &T_end &dt_fluid
*ICFD_CONTROL_FSI
$#     owc        bt
         0   &fsi_bt
*ICFD_CONTROL_OUTPUT
$#   msglv
         3
*ICFD_CONTROL_ADAPT
$#    minh      maxh       err       mth       nit
      2e-3      1e-2         5         0         3
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$                                                                              $
$                       ICFD PARTS/ SECTION/ MATERIAL                          $
$                                                                              $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*ICFD_SECTION
$#     sid   
         1
*ICFD_MAT
$#     mid       flg        ro       vis          
         1         1&rho_fluid &mu_fluid 
*ICFD_MAT
$#     mid       flg        ro       vis          
         2         0        
*ICFD_PART
$#     pid     secid       mid 
         1         1         1
*ICFD_PART
$#     pid     secid       mid 
         2         1         1
*ICFD_PART
$#     pid     secid       mid 
         3         1         1
*ICFD_PART
$#     pid     secid       mid 
         4         1         2
*ICFD_PART
$#     pid     secid       mid 
         5         1         2
*ICFD_PART
$#     pid     secid       mid 
         6         1         2
*ICFD_PART
$#     pid     secid       mid 
         7         1         2
*ICFD_PART
$#     pid     secid       mid 
         8         1         2
*ICFD_PART
$#     pid     secid       mid 
         9         1         2
*ICFD_PART_VOL
$#     pid     secid       mid 
        10         1         1
$#   spid1     spid2     spid3     spid4
         1         2         3   
*ICFD_PART_VOL
$#     pid     secid       mid 
        11         1         2
$#   spid1     spid2     spid3     spid4     spid5     spid6     spid7
         3         4         5         6         7         8         9
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$                                                                              $
$                    ICFD BOUNDARY/INITIAL CONDITIONS                          $
$                                                                              $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*ICFD_BOUNDARY_FREESLIP
$#     pid   
         1
*ICFD_BOUNDARY_FREESLIP
$#     pid   
         2
*ICFD_BOUNDARY_FREESLIP
$#     pid   
         4
*ICFD_BOUNDARY_NONSLIP
$#     pid   
         5
*ICFD_BOUNDARY_FSI
$#     pid   
         5
*ICFD_BOUNDARY_FREESLIP
$#     pid   
         6
*ICFD_BOUNDARY_FREESLIP
$#     pid   
         7
*ICFD_BOUNDARY_FREESLIP
$#     pid   
         8
*ICFD_BOUNDARY_FREESLIP
$#     pid   
         9
*LOAD_BODY_Y
$#    lcid        sf       
         1        1          
*DEFINE_CURVE_TITLE
Gravity force
$#    lcid      sidr       sfa       sfo      offa      offo    dattyp
         1                    &grav
$#                a1                  o1
                 0.0                 1.0
             10000.0                 1.0
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$                                                                              $
$                            ICFD MESH KEYWORDS                                $
$                                                                              $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*MESH_VOLUME
$#   volid     
        10
$#    pid1      pid2      pid3      pid4      pid5      pid6      pid7      pid8    
         1         2         4         5         6         7         8         9
*MESH_INTERF
$#     pid     
        10
$#   spid1
         3
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
$                                                                              $
$                             DATABASE (OUTPUT)                                $
$                                                                              $
$---+----1----+----2----+----3----+----4----+----5----+----6----+----7----+----8
*ICFD_DATABASE_DRAG
$#     pid
         5
*DATABASE_BINARY_D3PLOT
&dt_plot
*END

Figures

figure_001

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Description

A  water column collapses and impacts an elastic structure. This is a frequently used validation problem for which no experimental results were found. It uses mesh adaptivity to reduce the size of the mesh is zones were few flow features needs to be captured in order to save calculation time.

References :

[1] World Congress on Engineering, An SPH Approach for
Fluid-Hypoelastic Structure Interactions with Free Surfaces, (London,
U.K), WCE, July 2011

[2] S. Idelsohn, J. Marti, A. Limache, and E. Oñate, “Unified lagrangian
formulation for elastic solids and incompressible fluids: Application to
fluid–structure interaction problems via the {PFEM},” Computer
Methods in Applied Mechanics and Engineering, vol. 197, no. 19–20,
pp. 1762 – 1776, 2008.
Computational Methods in Fluid–Structure Interaction

[3] J. Marti, S. Idelsohn, A. Limache, N. Calvo, and J. D’Elía, “A fully
coupled particle method for quasi-incompressible fluid-hypoelastic
structure interactions,” Mechanica Computacional, vol. 25,
pp. 809–827, 2006.

[4] E. Walhorn, A. Kölke, B. Hübner, and D. Dinkler, “Fluid–structure
coupling within a monolithic model involving free surface flows,”
Computers and Structures, vol. 83, no. 25–26, pp. 2100 – 2111, 2005.