关于流固耦合在ANSYS建模中的实现！

sysh320

最后给出一个典型算例－水箱跌落的部分关键字：
*KEYWORD
*TITLE
boxwater2.k: dropping a water box onto a rigid platform
$========================================================================
$ [1] EXECUTION CONTROLS
$========================================================================
*CONTROL_TERMINATION
$ ENDTIM ENDCYC DTMIN ENDENG ENDMAS
0.0500000 0 0.0000000 0 0.0000000
*CONTROL_TIMESTEP
$ DTINIT TSSFAC ISDO TSLIMT DT2MS LCTM ERODE MS1ST
0.0000000 0.2000000 0 0.0000000 0.0000000 0 0 0
*CONTROL_ENERGY
$ HGEN RWEN SLNTEN RYLEN
2 2 2 2
$========================================================================
$ [3] OUTPUT CONTROLS
$========================================================================
*DATABASE_BINARY_D3PLOT
$ DT CYCL LCDT BEAM
0.0005000 0
*DATABASE_GLSTAT
0.0001000
$========================================================================
$ [5] |SECTIONS|PARTS| DEFs
$========================================================================
*PART
water in the box
$ PID SECID MID EOSID HGID GRAV ADPOPT TMID
1 1 1 1 0 0 0 0
*SECTION_SOLID_ALE
$ SECID ELFORM AET
1 12
$ AFAC BFAC CFAC DFAC START END AAFAC
0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000
$-------------------------------------------------------------------------------
*MAT_NULL
$ MID RHO PC MU TEROD CEROD YM PR
1 1000.0000 -1.000+10 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000
*EOS_LINEAR_POLYNOMIAL
$ EOSID C0 C1 C2 C3 C4 C5 C6
1 0.0000000 1.50000+9 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000
$ E0 V0
0.0000000 1.0000000
$========================================================================
*PART
void portion in the box
2 1 1 1 0 0 0 0
*INITIAL_VOID_PART
2
$========================================================================
*PART
rigid box containing water
$ PID SECID MID EOSID HGID GRAV ADPOPT TMID
3 3 3 0 0 0 0 0
*SECTION_SOLID
$ SECID ELFORM AET
3 0
*MAT_RIGID
3 2000.0000 1.00000+8 0.0000000 0.0000000 0.0000000 0.0000000
0.0000000 0.0000000 0.0000000
0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000 0.0000000
$========================================================================
*PART
rigid super-heavy platform
$ PID SECID MID EOSID HGID GRAV ADPOPT TMID
4 4 4
*SECTION_SHELL
$ SID ELFORM SHRF NIP PROPT QR/IRID ICOMP
4 0
$ T1 T2 T3 T4 NLOC
0.011 0.011 0.011 0.011
*MAT_ELASTIC
$ MID RHO E PR DA DB K
4 1000000.0 1.0000+14
$========================================================================
$ [8] BC's + IC's + BODY LOADS + FORCE FIELDS
$========================================================================
*INITIAL_VELOCITY
$ NSID NSIDEX BOXID
0
$ VX VY VZ VXR VYR VZR
0.0 -20.0 0.0
$-------------------------------------------------------------------------------
*LOAD_BODY_Y
$ LCID SF LCIDDR XC YC ZC
1 1.00
*DEFINE_CURVE
$ LCID SIDR SFO OFFA OFFO DATTYP
1
$ X=abcissa Y=ordinate
0.0 981.0
1.0 981.0
$========================================================================
$ [9] LAGRANGIAN CONTACTS CONSTRAINTS, ...
$========================================================================
$ SFS = scale fact on dflt SLAVE penal stifns (see CONTROLL_CONTACT)
$ SFM = scale fact on dflt MASTER penal stifns (see CONTROLL_CONTACT)
*CONTACT_AUTOMATIC_NODES_TO_SURFACE
$ SSID MSID SSTYP MSTYP SBOXID MBOXID SPR MPR
3 4 3 3
$ FS FD DC VC VDC PENCHK BT DT

$ SFS SFM SST MST SFST SFMT FSF VSF
100. 100.
$========================================================================
$ [10] EULERIAN & ALE CONTACTS CONSTRAINTS, ...
$========================================================================
*CONTROL_ALE
$ DCT NADV METH AFAC BFAC CFAC DFAC EFAC
2 1 4-1.0000000 0.0000000 0.0000000 0.0000000
$ START END AAFAC VFACT VLIMIT EBC
0.0000000 0.0000000 0.0000000 0.0
*ALE_REFERENCE_SYSTEM_GROUP
$ SID STYPE PRTYP PRID BCTRAN BCEXP BCROT ICOORD
1 0 5 1
$ XC YC ZC EXPLIM

*SET_PART_LIST
$ SID DA1 DA2 DA3 DA4
1
$ PID1 PID2 PID3 PID4 PID5 PID6 PID7 PID8
1 2
*ALE_REFERENCE_SYSTEM_NODE
$ NSID
1
$ N1 N2 N3 N4 N5 N6 N7 N8
5 6 7

sysh320

2、 SPH算法
SPH算法作为DYNA中第一种无网格（meshfree）算法，在连续体的破碎或分离分析中得到了广泛的关注和应用。在解决极度

变形和破坏类型的问题上SPH有着其他方法无法比拟的优势，可以说无网格算法正在成为数值分析领域的研究热点，具有很

好的发展前景。
我们知道传统的有限单元法中，单元的形状对结果的精度影响很大，如果单元因为变形过大可能造成矩阵奇异，使得精度降

低甚至无法计算下去。而SPH算法则是把每个粒子作为一个物质的插值点，各个粒子间通过规则的内插函数计算全部质点即

可得到整个问题的解。
主要的关键字如下：
*section_sph
提供算法选择，以及sph粒子的滑顺长度的定义；
*control_sph
提供sph算法的控制，如粒子排序后的循环次数、计算空间、中止时间以及维数；
处理sph粒子与其它结构的相互作用采用接触算法。
下面给出某一算例的部分命令流：
*KEYWORD
*TITLE
sph test
$
*DATABASE_FORMAT
0
$units:cm,gm,us
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ CONTROL OPTIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*CONTROL_PARALLEL
1
*CONTROL_ENERGY
2 2 2 2
*CONTROL_SHELL
20.0 1 -1 1 2 2 1
*CONTROL_TIMESTEP
0.0000 0.9000 0 0.00 0.00
*CONTROL_TERMINATION
$1000.0000 0 0.00000 0.00000 0.00000
0.800E+05 0 0.00000 0.00000 0.00000
*CONTROL_SPH
2 0
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ TIME HISTORY $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*DATABASE_BINARY_D3PLOT
200.0E+00
$0.500E+00
*DATABASE_BINARY_D3THDT
0.8000E+02
*DATABASE_EXTENT_BINARY
0 0 3 1 0 0 0 0
0 0 4 0 0 0
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ SECTION DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*SECTION_SOLID
2 1
*SECTION_SPH
1
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ MATERIAL DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*MAT_RIGID
2 7.80 2.10 0.300000 0.0 0.0 0.0
1.00 7.00 7.00

*MAT_RIGID
3 7.80 2.10 0.300000 0.0 0.0 0.0
1.00 6.00 7.00

*MAT_RIGID
4 7.80 2.10 0.300000 0.0 0.0 0.0
1.00 6.00 7.00

*MAT_NULL
1 1.00
*EOS_GRUNEISEN
1 .1484000 1.9790000 .0000000 .0000000 .1100000 3.0000000 .0000000
.0000000
$
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ PARTS DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$
*PART
Part 1 for Mat 4 and Elem Type 1
1 1 1 1 0 0 0
$
*PART
Part 2 for Mat 2 and Elem Type 1
2 2 2 0 0 0 0
$
*PART
Part 3 for Mat 3 and Elem Type 1
3 2 3 0 0 0 0
*PART
Part 3 for Mat 3 and Elem Type 1
4 2 4 0 0 0 0
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ RIGID BOUNDRIES $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*LOAD_BODY_Y
2,1.0
*DEFINE_CURVE
2
0.0,9.8E-10
1.0,9.8E-10
$
*DEFINE_CURVE
1 0 1.000 1.000 0.000 0.000
0.000000000000E+00 1.000000000000E-04
1.000000000000E+05 1.000000000000E-04
*BOUNDARY_PRESCRIBED_MOTION_RIGID
3 2 0 1 -1.00 0 0.000 0.000
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ NODE DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*CONTACT_AUTOMATIC_NODES_TO_SURFACE
1 1 3 2 0 0 0 0
0.000 0.000 0.000 0.000 0.000 0 0.000 0.0000E+08
0.000 0.000 0.100 0.000 0.000 0.000 0.000 0.000
1 0.1000000 3
*SET_PART_LIST
1
2,3,4
*INCLUDE
mesh.k
*END

sysh320

3、 ALE（接触算法）
采用接触算法分析流固耦合问题也是一种选择，在液面波动幅度较小时可以采用此种方法进行分析，流体用ALE算法描述，

结构采用Lagrange算法；需要注意的一点：对ALE网格要进行滑顺处理，以控制网格形态，保证求解精度。
下面是某算例的部分命令流：

*KEYWORD
*TITLE
ALE
$
*DATABASE_FORMAT
0
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ CONTROL OPTIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*CONTROL_PARALLEL
1
*CONTROL_ENERGY
2 2 2 2
*CONTROL_ALE
3 1 2 1.0000000 1.0000000 0.000000 1.0000000
1.0000e+9 0.000000 0.000000 2
*CONTROL_TIMESTEP
0.0000 0.9000 0 0.00 0.00
*CONTROL_CONTACT
0.0000000 0.0000000 1 0 2 0 0
0 0 0 0
*CONTROL_TERMINATION
0.100E+05 0 0.00000 0.00000 0.00000
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ TIME HISTORY $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*DATABASE_BINARY_D3PLOT
0.1000E+03
*DATABASE_BINARY_D3THDT
0.1000E+02
*DATABASE_EXTENT_BINARY
0 0 3 1 0 0 0 0
0 0 4 0 0 0
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ SECTION DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*SECTION_SOLID
2 1
*SECTION_SOLID_ALE
1 5
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ MATERIAL DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*MAT_RIGID
2 7.80 2.10 0.280000 0.0 0.0 0.0
1.00 7.00 7.00

*MAT_RIGID
3 7.80 2.10 0.280000 0.0 0.0 0.0
1.00 6.00 7.00

*MAT_RIGID
4 7.80 2.10 0.280000 0.0 0.0 0.0
1.00 6.00 7.00

*MAT_NULL
1 1.0000000 0.0000000 1.00000-8 0.0000000 0.0000000 0.0000000 0.0000000
*EOS_LINEAR_POLYNOMIAL
1 1.00000-6 1.92100-3 0.0000000 0.0000000 0.4000000 0.4000000 0.0000000
0.0000000 0.0000000
$
$
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ PARTS DEFINITIONS $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
$
*PART
Part 1 for Mat 4 and Elem Type 1
1 1 1 1 0 0 0
$
*PART
Part 2 for Mat 2 and Elem Type 1
2 2 2 0 0 0 0
$
*PART
Part 3 for Mat 3 and Elem Type 1
3 2 3 0 0 0 0
*PART
Part 3 for Mat 3 and Elem Type 1
4 2 4 0 0 0 0
$
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$ RIGID BOUNDRIES $
$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
$
*CONTACT_SURFACE_TO_SURFACE
1 2 3 3 0 0 0 0
0.0000 0.0000 0.0000 0.0000 0.0000 0 0.00000.1000E+08
1.0000 0.0001 0.0000 0.0000 1.0000 1.0000 1.0000 1.0000
*CONTACT_SURFACE_TO_SURFACE
1 3 3 3 0 0 0 0
0.0000 0.0000 0.0000 0.0000 0.0000 0 0.00000.1000E+08
1.0000 0.0001 0.0000 0.0000 1.0000 1.0000 1.0000 1.0000
*CONTACT_SURFACE_TO_SURFACE
1 4 3 3 0 0 0 0
0.0000 0.0000 0.0000 0.0000 0.0000 0 0.00000.1000E+08
1.0000 0.0001 0.0000 0.0000 1.0000 1.0000 1.0000 1.0000
$
*DEFINE_CURVE
1 0 1.000 1.000 0.000 0.000
0.000000000000E+00 1.000000000000E-04
1.000000000000E+05 1.000000000000E-04
*BOUNDARY_PRESCRIBED_MOTION_RIGID
3 2 0 1 -1.00 0 0.000 5.00e3
*BOUNDARY_PRESCRIBED_MOTION_RIGID
4 2 0 1 -1.00 0 5.00e3 0.000
$
通常我们处理液面晃动采用上述方法，LS-DYNA求解器在下一个版本LS970中在MESHFREE功能上增加了更为稳定和高效的EFG

技术，在解决此类问题上将给予我们更大的灵活性和更多的选择。

xuweirong

今天刚发现这个论坛，好开心！
和楼主一样，我也在做脱流塔和浆液耦合的分析，之前没做过，所以遇到不少问题！
我的壳单元选用的是181，流体单元选用的是30，我想用FSI solver 法进行分析，但是现在卡在设置边界条件和标记耦合界面上，不知道怎样做。最近两天一直在研究ansys帮助，不过具体怎样做还不是很清楚，不知道楼主是怎样处理的，希望能得到你的帮助！

sysh320

我是通过设置流体单元的关键字还实现接触与非接触的，边界条件的话，我是用的底部固结，当然也可以在地脚锚栓处固结。这个差别都不是很大的
我还想再用80号单元再做做耦合，有问题咱们一起交流

陶乐子

sysh320你好
我也是搞结构与液体耦合的，但是新手
我想请问你几个基本的问题，对液体中的某结构进行模态分析的话，应该在哪种环境中实现？液体应该用什么单元？
请赐教！
谢谢！

xuweirong

我在网上看到有人说ansys公司技术人员建议对流固耦合模态分析使用fluid80单元，然后看了以下ansys帮助中说 The fluid80 element is particularly well suited for calculating hydrostatic pressures and fluid/solid interactions，我也想用fluid80试试。

张静娜

为什么不用fluid141单元？我也在做结构流体耦合的东西，探讨中。

jht0421

没接触过流固耦合，但是感觉如果有需要的时候在这里边肯定有很多自己需要的，谢谢楼主

Antony21

如将压电薄板至入水中，观测其共振频率，该使用何种方法呢
目前是采用Fluids Analysis中的Acoustics，不知道方向对不对， 因为按照HELP上面的方式操作，不管有没有加入水，频率都是一样的， 正确结果频率应该是要改变的，就是不知道哪里出了错，不知前辈有否做过类似的问题， 牵涉了结构、电及流体

[ 本帖最后由 Antony21 于 2007-6-22 17:28 编辑 ]

jsp613

这个例子在哪？

yaolonghe

刚开完第五届国际非线性力学会议，碰到了国际水波动力学的巨牛c.c.mei。我跟他交流过这方面的问题，最后讨论的结果是边界交换技术，大家可以继续讨论……

xfyoung

[quote]原帖由 Antony21 于 2007-6-22 17:23 发表

                               
登录/注册后可看大图

如将压电薄板至入水中，观测其共振频率，该使用何种方法呢
目前是采用Fluids Analysis中的Acoustics，不知道方向对不对， 因为按照HELP上面的方式操作，不管有没有加入水，频率都是一样的， 正确结果频率应该是 ... [/quot、

    同样问题，有没有大虾研究水下压电换能器特性的？请指点一二。

xuweirong

sysh320你好：
    上次做的脱硫塔于浆液耦合的分析中间有事就一直停下来没做，前两天又拾起来接着做。现在遇到了一些问题，我也查不出是什么原因造成的：就是我在用sf家族命令标记耦合界面时，出现了这样的错误                        *** ERROR ***                           CP=     29.297   TIME= 22:15:44
Number of FLUID/SOLID interfaces do not match for FSIN boundary         
condition.                                                              

*** ERROR ***                           CP=     29.641   TIME= 22:15:48
Error during fsi setup - Skipping the remaining FSI analysis.           
下面是我标记耦合界面的命令流：
!对塔体底部加约束
lsel,s,,,54,63
nsll,s,1
d,all,all
!求解
!*** FSI interfaces
!!fluid  side

asel,s,,,16,37,3
allsel,below,area
nsla,s,1
sf,all,fsin,1

!structural side

asel,s,,,39,78
allsel,below,area
nsla,s,1
sf,all,fsin,1

allsel
/solu
fldata,solu,flow,1
fldata,solu,ale,1     
fldata,solu,turb,1
fldata,solu,tran,1
fldata,iter,exec,50
!Fluid Properties
fldata7,prot,dens,constant
fldata7,prot,visc,constant

fldata8,nomi,dens,1000.   ! 1000 kg/m3 for density - water
fldata8,nomi,visc,4.6E-4  ! 4.6E-4 kg-s/m (viscosity of water)
fldata8,conv,pres,1.E-8   ! Tighten pressure equation convergence

fsan,on                  !FSI analysis on
fsco,all,1.0e-1          !FSI convergence criteria
fsre,all,0.5             !FSI relaxation
fsou,1                   !FSI output frequency
fsit,5                  !Number of stagger loops
fsti,0.05                !FSI end time
fsdt,0.01                !FSI delta time
fsor,fluid               !FSI order of solution
fstr,solid,              !Transient fluid for FSI analysis
fstr,fluid,              !Transient structural for FSI analysis
deltim,0.01
fldata,time,step,0.01
save
solve
真诚的希望你有时间能帮我看看，是不是我哪里设置的不对，还是其它什么原因？非常感谢！

张静娜

流固耦合专区的群，大家进来一起讨论。