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几个ansys流固耦合的例子


一般说来,ANSYS 的流固耦合主要有 4 种方式: 1,sequential 这需要用户进行 APDL 编程进行流固耦合 sequentia 指的是顺序耦合 以采用 MpCCI 为例,你可以利用 ANSYS 和一个第三方 CFD 产品执行流固耦合分析。 在这个 方法中,基于网格的平行代码耦合界面(MpCCI) 将 ANSYS 和 CFD 程序耦合起来。即使网 格上存在差别, MpCCI 也能够实现流固界面的数据转换。 ANSYS CD 中包含有 MpCCI 库和 一个相关实例。关于该方法的详细信息,参见 ANSYS Coupled-Field Analysis Guide 中的 Sequential Couplin 2,FSI solver 流固耦合的设置过程非常简单,推荐你使用这种方式 3,multi-field solver 这是 FSI solver 的扩展,你可以使用它实现流体,结构,热,电磁等的耦合 4,直接采用特殊的单元进行直接耦合,耦合计算直接发生在单元刚度矩阵 一个流固耦合的例子 length=2 width=3 height=2 /prep7 et,1,63 et,2,30 !选用 FLUID30 单元,用于流固耦合问题 r,1,0.01 mp,ex,1,2e11 mp,nuxy,1,0.3 mp,dens,1,7800 mp,dens,2,1000 !定义 Acoustics 材料来描述流体材料-水 mp,sonc,2,1400 mp,mu,0, ! block,,length,,width,,height esize,0.5 mshkey,1 ! type,1 mat,1 real,1 asel,u,loc,y,width amesh,all alls ! type,2 mat,2 vmesh,all

fini /solu antype,2 modopt,unsym,10 !非对称模态提取方法处理流固耦合问题 eqslv,front mxpand,10,,,1 nsel,s,loc,x, nsel,a,loc,x,length nsel,r,loc,y d,all,,,,,,ux,uy,uz, nsel,s,loc,y,width, d,all,pres,0 alls asel,u,loc,y,width, sfa,all,,fsi !定义流固耦合界面 alls solv fini /post1 set,first plnsol,u,sum,2,1 fini

再给大家一个实例! 考虑结构在水中的自振频率:例子是一加筋板在水中的模态分析。 命令流如下: FINISH /CLEAR /FILENAME,plane /UNITS,SI /TITLE,plane /PREP7 !*********ELEMENT DEFINE******** ET,63,63 ET,4,beam4 et,30,fluid30 !****MATERIAL DEFINE********* MP,EX,1,2.10E11 MP,DENS,1,7850

MP,NUXY,1,0.3 mp,dens,30,1025 mp,sonc,30,1500 mp,mu,30,0.5 !*******REAL CONSTANT*********** r,30,1e-06 r,50,0.05 r,75,0.375e-02,0.78125e-06,0.000016406 k,1 k,4,1 kfill,1,4,2,,1 kgen,4,1,4,1,,1/3,,10 a,1,2,12,11 *do,i,0,2 *do,j,0,2*10,10 a,1+i+j,2+i+j,12+i+j,11+i+j *enddo *enddo !***************************fluid element**************** k,100,-14.5,-14.5 k,101,-14.5,15.5 k,102,15.5,15.5 k,103,15.5,-14.5 k,140,-14.5,-14.5,30 k,141,-14.5,15.5,30 k,142,15.5,15.5,30 k,143,15.5,-14.5,30 a,100,101,102,103,4,14,24,34,33,32,31,21,11,1 a,1,2,3,4,103,100 a,140,141,142,143 a,100,101,141,140 a,101,102,142,141 a,142,143,103,102 a,140,143,103,100 a,14,24,34,33,32,31,21,11,1,2,3,4 asel,u,,,1, FLST,2,8,5,ORDE,2okok.org FITEM,2,10okok.org FITEM,2,-17okok.org VA,P51Xokok.org nummrg,all alls

MSHKEY,0 MSHAPE,0 esize,1 lsel,s,loc,y,1/3 lsel,r,loc,x,0,1 lsel,r,loc,z,0 latt,1,75,4 lmesh,all lsel,s,loc,y,2/3 lsel,r,loc,x,0,1 lsel,r,loc,z,0 latt,1,75,4 lmesh,all lsel,s,loc,x,1/3 lsel,r,loc,y,0,1 lsel,r,loc,z,0 latt,1,75,4 lmesh,all lsel,s,loc,x,2/3 lsel,r,loc,y,0,1 lsel,r,loc,z,0 latt,1,75,4 lmesh,all asel,s,,,1,9 aatt,1,50,63 amesh,all alls MSHAPE,1,3d esize,3 vsel,s,,,1 type,30 $mat,30 $real,30 vmesh,all alls FINISH /solu alls !**** 求解 *********** !********************* ANTYPE,MODAL MODOPT,lanb,25,0 SOLVE FINISH

总是出现 error 说矩阵不对称,不可以用 lanb 计算。 总结:流体单元不能用对称的解法 应该采用非对称解法。

例子是一圆环在水中的模态分析。命令流如下: finish /clear /PREP7 !定义单元类型 ET,1,PLANE42 ! structural element ET,2,FLUID29 ! acoustic fluid element with ux & uy ET,3,129 ! acoustic infinite line element r,3,0.31242,0,0 ET,4,FLUID29,,1,0 ! acoustic fluid element without ux & uy !材料属性 MP,EX,1,2.068e11 MP,DENS,1,7929 MP,NUXY,1,0 MP,DENS,2,1030 MP,SONC,2,1460 ! 创建四分之一模型 CYL4,0,0,0.254,0,0.26035,90 CYL4,0,0,0.26035,0,0.31242,90 ! 选择属性,网格划分 ASEL,S,AREA,,1 AATT,1,1,1,0 LESIZE,1,,,16,1 LESIZE,3,,,16,1 LESIZE,2,,,1,1 LESIZE,4,,,1,1 MSHKEY,1 MSHAPE,0,2D ! mapped quad mesh AMESH,1 ASEL,S,AREA,,2 AATT,2,1,2,0 LESIZE,5,,,16,1 LESIZE,7,,,16,1 LESIZE,6,,,5 LESIZE,8,,,5 MSHKEY,0 MSHAPE,0,2D ! mapped quad mesh

AMESH,2 ! 关于 Y 轴镜像 nsym,x,1000,all ! offset node number by 1000 esym,,1000,all ! 关于 y 轴镜像 nsym,y,2000,all ! offset node number by 2000 esym,,2000,all NUMMRG,ALL ! merge all quantities esel,s,type,,1 nsle,s esln,s,0 nsle,s esel,inve nsle,s emodif,all,type,4 esel,all nsel,all ! 指定无限吸收边界 csys,1 nsel,s,loc,x,0.31242 type,3 real,3 mat,2 esurf esel,all nsel,all ! 标识流固交接面 nsel,s,loc,x,0.26035 esel,s,type,,2 sf,all,fsi,1 nsel,all esel,all FINISH /solu antype,modal modopt,damp,10 mxpand,10,,,yes solve finish 为了便于对比,也对圆环在空气中做了模态分析 finish /clear /PREP7 !定义单元类型

ET,1,PLANE42 ! structural element !材料属性 MP,EX,1,2.068e11 MP,DENS,1,7929 MP,NUXY,1,0 ! 创建四分之一模型 CYL4,0,0,0.254,0,0.26035,90 ! 选择属性,网格划分 ASEL,S,AREA,,1 AATT,1,1,1,0 LESIZE,1,,,16,1 LESIZE,3,,,16,1 LESIZE,2,,,1,1 LESIZE,4,,,1,1 MSHKEY,1 MSHAPE,0,2D ! mapped quad mesh AMESH,1 ! 关于 Y 轴镜像 nsym,x,1000,all ! offset node number by 1000 esym,,1000,all ! 关于 y 轴镜像 nsym,y,2000,all ! offset node number by 2000 esym,,2000,all NUMMRG,ALL /solu antype,modal modopt,lanb,10 mxpand,10,,,yes solve finish 在水中的自振频率为 SET TIME/FREQ LOAD STEP SUBSTEP CUMULATIVE 1-0.19544E-10 1 1 1 2 0.29640E-03 1 1 1 3-0.21663E-10 1 2 2 4-0.29640E-03 1 2 2 5 0.30870E-03 1 3 3 6 0.0000 1 3 3 7-0.30870E-03 1 4 4 8 0.0000 1 4 4 9-0.53726E-03 1 5 5 10 0.57522E-11 1 5 5 11 0.53726E-03 1 6 6 12-0.89057E-11 1 6 6

13 0.98059E-01 1 7 7 14 35.232 1 7 7 15 0.98059E-01 1 8 8 16 -35.232 1 8 8 17 0.98061E-01 1 9 9 18 35.233 1 9 9 19 0.98061E-01 1 10 10 20 -35.233 1 10 10 在空气中的自振频率为 SET TIME/FREQ LOAD STEP SUBSTEP CUMULATIVE 1 0.0000 1 1 1 2 0.0000 1 2 2 3 0.73609E-03 1 3 3 4 60.805 1 4 4 5 60.805 1 5 5 6 172.97 1 6 6 7 172.97 1 7 7 8 334.40 1 8 8 9 334.40 1 9 9 10 546.59 1 10 10 主要有以下疑问: 1) 考虑流固耦合, 做模态分析时流体单元是否只能用 fluid29 2d) fluid30 3d),对于 fluid129 ( 和 ( 和 fluid130 在耦合中具体起到什么作用,能不能不设,而用边界约束条件代替? 2)流体范围怎样确定,如本例中(CYL4,0,0,0.26035,0,0.31242,90) ,外半径为 0.31242。如 果不是环形的,如一块当水板,该怎样考虑? 3)如果不考虑流体的压缩性,把声速设的很大,MP,SONC,2,1e20,就可以了。 4)从自振频率可以看出,在水中和在空气中,圆环的自振频率差别特别大,且振型也大相 径庭,为什么?在水中时,模态提取方法用 damp(为什么不能用 unsym) ,特征值的虚部代 表角频率,为什么第一阶为正,第二阶为负,而第三阶和第四阶都为 0,第六阶、八阶、十 阶都为负。应该是从小到大才对? 5)在空气中时,模态提取方法用 lanb,为什么第一阶第二阶的频率都为 0。 请高手指点迷津,急盼中 对以上问题的解答: 频率为零,一般是发生了刚体位移,估计你是把水抽走,而没有限制圆环。 1。圆环在水中振动必然导致波动(其实就是声波)在水中传播,当声波到达水的另一个界面 时就会发生反射(除非水和另一个相邻体的声阻抗是匹配的)。水和金属中的声速相差不大, 即可压缩性相差不大。 两种可压缩性相差不大的物质的相互作用对两者影响都很大。 圆环在 水中振动,水对圆环的反作用是由于反射波引起的,流固耦合中采用 fluid129 和 130 就是最 大程度的减弱反射波。 2。声波从圆环开始传播,随着传播距离的增加,波阵面不断增大,振幅不断减小。同时由 于水的衰减,声波也不断减弱。如果水的空间越大,则反射波返回圆环的路径越长,衰减也 就越多,影响也就越小。fluid129 和 130 对反射波的衰减(通过很小的反射实现)有限,因此

还需要水要有足够的空间。fluid129 和 130 离结构应该大于 0.2λ(λ=c/f,c 为水中声速)。以上 的做法在误差允许的情况下等效于水在无限大水空间中的情况。 如果是挡水板, 水就是有限 空间了,情况也不一样。 3。声速加大情况也不一样,就是不知是不是你所要的情况? 4。空气作为介质,由于其声速比金属小很多,可压缩性大很多,影响可以忽略不计。而水 的影响就不同了。 这可能就是频率和振型不同的原因吧?我试了你的例子, 各种提取方法都 可以。 5。空气的影响忽略不计,因此需要对圆环进行约束。你没有约束,那么就会发生静态位移 即频率为零。圆环有两个对称轴,因此会发生频率成对出现的情况。也就是说,两个方向上 有同样的振型。

接触分析实例---包含初始间隙 fini /clear,nostart /prep7 et,1,82 KEYOPT,1,3,3 r,1,0.5 mp,ex,1,1e9 mp,prxy,1,0.3 k,1,0,0 k,2,10,0 k,3,10,5 k,4,6.2,5 k,5,7.5,3.4 k,6,2.5,3.4 k,7,3.8,5 k,8,0,5 a,1,2,3,4,5,6,7,8 LFILLT,6,5,0.18, , LFILLT,5,4,0.18, , FLST,2,3,4 FITEM,2,9 FITEM,2,11 FITEM,2,10 AL,P51X FLST,2,3,4 FITEM,2,13 FITEM,2,14

FITEM,2,12 AL,P51X FLST,2,3,5,ORDE,2 FITEM,2,1 FITEM,2,-3 AADD,P51X rect,0,10,4.8,5 ASBA, 4, gap=0.02 k,24,6.2-gap,5 k,25,7.5-gap,3.4 k,26,2.5+gap,3.4 k,27,3.8+gap,5 a,24,25,26,27 LFILLT,4,3,0.2, , LFILLT,3,2,0.2, , FLST,2,3,4 FITEM,2,7 FITEM,2,10 FITEM,2,8 AL,P51X FLST,2,3,4 FITEM,2,13 FITEM,2,14 FITEM,2,11 AL,P51X FLST,3,2,5,ORDE,2 FITEM,3,3 FITEM,3,-4 ASBA, 1,P51X rect,3.8+gap,6.2-gap,5,10 rect,3.8+gap,3.8+gap+8,10,12 FLST,2,3,5,ORDE,3 FITEM,2,1 FITEM,2,3 FITEM,2,5 AADD,P51X rect,3.8+gap+8,3.8+gap+8+2,10,12 FLST,2,2,5,ORDE,2 FITEM,2,1

1

FITEM,2,4 AGLUE,P51X CYL4,2.0,1.8,0.6 CYL4,7.0,1.8,0.6 FLST,2,3,5,ORDE,3 FITEM,2,2 FITEM,2,4 FITEM,2,-5 AOVLAP,P51X esize,0.2 amesh,all FLST,5,135,2,ORDE,32 FITEM,5,485 FITEM,5,576 FITEM,5,-577 FITEM,5,621 FITEM,5,-625 FITEM,5,707 FITEM,5,-711 FITEM,5,716 FITEM,5,741 FITEM,5,-745 FITEM,5,750 FITEM,5,-751 FITEM,5,766 FITEM,5,797 FITEM,5,-798 FITEM,5,854 FITEM,5,888 FITEM,5,-938 FITEM,5,1101 FITEM,5,1103 FITEM,5,1420 FITEM,5,1628 FITEM,5,1653 FITEM,5,1696 FITEM,5,1699 FITEM,5,-1702 FITEM,5,1726 FITEM,5,-1728 FITEM,5,1852

FITEM,5,-1874 FITEM,5,2044 FITEM,5,-2066 CM,_Y,ELEM ESEL, , , ,P51X CM,_Y1,ELEM CMSEL,S,_Y CMDELE,_Y EREF,_Y1, , ,1,0,1,1 CMDELE,_Y1

ET,2,TARGE169 ET,3,CONTA172 R,3, , , R,3,0,0,0.1, 10,0,0 R,4, , , R,4,0,0,0.1, 10,-0.02,0

lsel,s,,,9 lsel,a,,,5 lsel,a,,,12 nsll,s,1 type,3 real,3 esurf,all alls, lsel,s,,,19 lsel,a,,,20 nsll,s,1 type,3 real,4 esurf,all alls, lsel,s,,,7 lsel,a,,,3 lsel,a,,,11 nsll,s,1 type,2 real,3 esurf,all

alls, lsel,s,,,25 lsel,a,,,26 nsll,s,1 type,2 real,4 esurf,all alls, FLST,2,2,5,ORDE,2 FITEM,2,4 FITEM,2,-5 DA,P51X,ALL, FLST,2,1,4,ORDE,1 FITEM,2,6 SFL,P51X,PRES,500, /solu antype,0 nlgeom,on outres,all,all nsubst,200,200,2 neqit,1000 solve

耦合小程序 最近用到耦合,写了一段小程序,奉献出来,与大家共享。 如果有很多节点,每两个节点位置相同,如果将这些杂乱无章的节点 耦合,是件很麻烦的事,可用这段程序,轻松解决。 cpnum=0 cmsel,s,n-zhong !需要耦合的节点 *GET,n_num,NODE,,COUNT, , , , !节点总数

*do,i,1,n_num cmsel,s,n-zhong *GET,n_lowest,NODE,,NUM,MIN, , , , !号码最小的节点 *GET,n_x,NODE,n_lowest,LOC,X !该节点坐标 *GET,n_y,NODE,n_lowest,LOC,Y *GET,n_z,NODE,n_lowest,LOC,Z NSEL,s,LOC,X,n_x-0.3,n_x+0.3 !寻找与该节点位置相同的节点 NSEL,R,LOC,Y,n_y-0.3,n_y+0.3 NSEL,R,LOC,z,n_z-0.3,n_z+0.3 cm,n_cp_cp,node !位置相同的节点形成一个组 cmsel,s,n-zhong cmsel,u,n_cp_cp cm,n-zhong,node !取消这些点后剩余的点形成组 *GET,n_num_1,NODE,,COUNT, , , , !节点总数 *if,n_num_1,lt,2,exit !如果节点数小于二则退出 cmsel,s,n_cp_cp *GET,n_num,NODE,,COUNT, , , , *if,n_num,gt,1,then CP,cpnum+1,ux,all CP,cpnum+2,uy,all CP,cpnum+3,uz,all cpnum=cpnum+3 *else

*endif *enddo

该段程序可用 CPINTF,UX,0.001 CPINTF,UY,0.001 CPINTF,UZ,0.001 代替

*DO,I,2,296,3 CP,I,UX,I,I+2 *ENDDO *DO,I,2,296,3 CP,I,UY,I,I+2 *ENDDO *DO,I,2,296,3 CP,I,UZ,I,I+2 *ENDDO DK,1, , , ,0,UX,UY,UZ, , , , 以上几句改为: *DO,I,2,296,3 CP,NEXT,ALL,I,I+2 *ENDDO DK,1, , , ,0,ALL 或 CPINTF,ALL,0.001 因为你选用的单元有六个自由度,如果只约束三个,程序是不会运行的. 另:三次循环语句的 I 相等,约束 UY 时,UX 的耦合就被删掉了,最后只剩 UZ 了

这样修改: c***耦合练习 /PREP7 K,1,0,0

K,2,0.1,0 L,1,2 K,300,0,-10000 LGEN,100,1,,,0.1,,,2 ET,1,BEAM188 MP,EX,1,2.1e11 MP,PRXY,1,0.3 MP,DENS,1,0.783e4 SECTYPE, 1, BEAM, T, , 0 SECOFFSET, CENT SECDATA,0.06,0.03,0.003,0.006,0,0,0,0,0,0 LSEL,ALL LATT,1,1,1,,300 LESIZE,ALL,,,1,,1,,,1 LMESH,ALL cpintf,all DK,1,ux,0, , ,UY,UZ DK,200, , , , ,UY,UZ ACEL,0,9.8,0, FINISH

一个流固耦合的例子 这个例子关于装有水的水杯旋转,是轴对称问题,为了简化,所以选择了平面模型。 *SET,RAD,0.8 *SET,h,1 *SET,g,9.8 *SET,OMEGAR,2 *SET,ROU,1000 /PREP7 ET,1,FLUID79 KEYOPT,1,3,1 MP,EX,1,2E9 MP,DENS,1,ROU K,1 K,2,RAD K,3,RAD,H K,4,,,H K,4,,H A,1,2,3,4 LESIZE,ALL,,,10 AMESH,ALL

FINISH /SOL DL,2,,UX DL,1,,UY NSEL,S,LOC,X DSYM,SYMM,X D,ALL,UX D,ALL,UX NSEL,ALL ACEL,,G OMEGA,,OMEGAR SOLVE FINISH /POST1 SET,LAST PLNSOL,U,X,0,1 *SET,UCENT,UY(22) *SET,UEDGE,UY(12) *SET,UELEV,UEDGE-UCENT

ansys 从 9.0 发展到 10.0,一个最大的进步就是流固耦合计算更加规范,这一点已远领先于 其他同类软件, 实现了单向耦合到即时双向耦合的飞跃, 使用户对于解决流固耦合问题又多 了一种选择,希望大家对多种方法-----物理环境转换,fsi,mfx 等进行讨论,提供一下案例 本人抛砖引玉: 使用物理环境法进行流固耦合的实例及讲解 流道中有一橡胶垫阻碍水的流动,入口速度为 2m/s,其他参数将在命令流中详细给出。求 解水通过此流道的压力降,以及稳态条件下橡胶垫的变形。 /prep7 /sho,gasket,grph shpp,off ET,1,141 ! Fluid - static mesh ET,2,56, ! Hyperelastic element !!!!!!! Fluid Structure Interaction - Multiphysics !!!!!!! Deformation of a gasket in a flow field. ! !!!!!!! Element plots are written to the file gasket.grph. !

! - Water flows in a vertical pipe through a construction ! formed by a rubber gasket. ! - Determine the equilibrium position of the gasket and ! the resulting flow field ! ! | | ! | | ! |----------| Boundary of "morphing fluid" ! | ______| ! | |______ gasket ! | | ! |----------| Boundary of "morphing fluid" (sf) ! | | ! !! 1. Build the model of the entire domain: !! Fluid region - static mesh !! !! Gasket leaves a hole in the center of the duct !! Morphing Fluid region is a user defined region around !! the gasket. The fluid mesh here will deform and be !! updated as the gasket deforms. !! !! Parameterize Dimensions in the flow direction !! yent = 0.0 ! Y coordinate of the entrance to the pipe dyen = 1.0 ! Undeformed geometry flow entrance length ysf1 = yent+dyen ! Y coordinate of entrance to the morphing fluid region dsf1 = 0.5 ! Thickness of upstream ygas = ysf1+dsf1 ! Y coordinate of the bottom of the gasket dg = 0.02 ! Thickness of the gasket dg2=dg/2. ytg = ygas+dg ! Y coordinate of the initial top of the gasket dsf2 = 0.5 ! Thickness of downstream region ysf2 = ytg + dsf2! Y of Top of the downstream morphing fluids region dyex = 6.0 ! Exit fluid length x = 0. ! Location of the axisymmetric Centerline dgasr =.20 ! Initial span of gasket piper = 0.3 ! Radius of the pipe xrgap = piper-dgasr!! radius of completely unobtructed flow passage !! !!! Create geometry !! rect,xrgap,piper,ygas,ytg ! A1:Gasket (keypoints 1-4) rect,x,piper,ysf1,ysf2 ! A2: Morphing fluid region

rect,x,piper,yent,ysf1 ! A3: Fluid region with static mesh rect,x,piper,ysf2,ysf2+dyex ! A4: Fluid region with static mesh aovlap,all k,22,xrgap+dg2,ygas+dg2 rarc = dg2*1.1 larc,1,4,22,rarc al,6,4 adelete,7 al,6,3,22,7,8,5,21,1 !!Mesh Division information ngap = 10 ! Number elements across the gap ngas = 10 ! Number of elements along the gasket rgas = -2 ! Spacing ratio along gasket nflu = ngap+ngas ! Number of elements across the fluid region raflu = -3 ! Space fluid elements near the walls and center nenty =8 ! Elements along flow - entrance raent =5 ! Size ratio in the inlet region nfl1 = 20 ! Elements along flow - first morph.fluid. nthgas = 4 ! Elements in the gasket nfl2 = 3 ! Elements along flow - second morph.fluid. next = 30 ! Elements along flow - exit region rext = 6 ! Size ratio in flow direction of outlet rafls = 12 ! Initial element spacing ratio - morph.fluid lesize,1,,,ngas,rgas lesize,3,,,ngas,rgas nfl11= nfl1*2+9 lsel,s,,,2,4,2 ! (Modify lesize of line 8 if changing gasket mesh) lesize,all,,,nthgas alls lesize,5,,,nflu,raflu lesize,7,,,nflu,raflu lesize,9,,,nflu,raflu lesize,15,,,nflu,raflu lesize,18,,,nenty,1./raent lesize,17,,,nenty,1./raent lesize,21,,,nfl1,rafls lesize,8,,,nfl11,-1./(rafls+3) lesize,22,,,nfl1,rafls lesize,19,,,next,rext lesize,20,,,next,rext !!! AATT,MAT,REAL,TYPE asel,s,,,1,2 - Set the attributes for the areas

aatt,2,2,2 ! Gasket (material 2) asel,s,,,3 cm,area2,area alist ! List area selected for further morphing asel,a,,,5,6 aatt,1,1,1 ! Fluid area (material 1) alls eshape,2 asel,u,,,2,3 amesh,all eshape,0 asel,s,,,2,3 amesh,all !----------------!!!!! Create element plot and write to the file gasket.grph asel,s,,,1,3 esla,s /Title, Initial mesh for gasket and neighborhood eplot /ZOOM,1,RECT,0.3,-0.6,0.4,-0.5 alls !----------------!! !!!!! 2. Create Physics Environment for the Fluid et,1,141 et,2,0 ! Gasket becomes the Null Element vin=3.5e-1 ! Inlet water velocity (meters/second) !! CFD Solution Control flda,solu,flow,1 flda,solu,turb,1 flda,iter,exec,400 flda,outp,sumf,10 !! CFD Property Information flda,prot,dens,constant flda,prot,visc,constant flda,nomi,dens,1000. ! 1000 kg/m3 for density - water flda,nomi,visc,4.6E-4 ! 4.6E-4 kg-s/m (viscosity of water) flda,conv,pres,1.E-8 ! Tighten pressure equation convergence !! CFD Boundary Conditions (Applied to Solid Model) lsel,s,,,8,17,9 lsel,a,,,20 dl,all,,vx,0.,1 ! Centerline symmetry

lsel,s,,,9 dl,all,,vx,0.,1 dl,all,,vy,vin,1 ! Inlet Condition lsel,s,,,2 lsel,a,,,18,19 lsel,a,,,21,22 dl,all,,vx,0.,1 ! Outer Wall dl,all,,vy,0.,1 lsel,s,,,1,3,2 lsel,a,,,6 dl,all,,vx,0.,1 ! Gasket dl,all,,vy,0.,1 lsel,s,,,15 dl,15,,pres,0.,1 ! Outlet pressure condition !!! create named component of nodes at the bottom of gasket lsel,s,,,1 nsll,,1 cm,gasket,node nlist ! List initial nodal positions of the bottom of the gasket /com, +++++++++ STARTING gasket coordinates -------alls /title,Fluid Analysis physics,write,fluid,fluid !! !!!!! 3. Create Physics Environment for the Structure !! physics,clear et,1,0 ! The Null element for the fluid region et,2,56 ! Gasket element - material 2 mp,ex,2,2.82E+6 ! Young's modulus for rubber mp,nuxy,2,0.49967 ! Poisson's ratio for the rubber tb,mooney,2 tbdata,1,0.293E+6 ! Mooney-Rivlin Constants tbdata,2,0.177E+6 ! " " " lsel,s,,,2 nsll,,1 d,all,ux,0. d,all,uy,0. alls

! Fix the end of the gasket

/title,structural analysis finish

/solu antype,static nlgeom,on cnvtol,f,,,,-1 physics,write,struc,struc physics,clear save !! !!!!! 4. Fluid-Structure Interaction Loop !! loop=25 ! Maximum allowed number of loops toler=0.005 ! Convergence tolerance for maximum displacement *dim,dismax,array,loop ! Define array of maximum displacement values *dim,strcri,array,loop ! Define array of convergence values *dim,index,array,loop *do,i,1,loop ! Execute fluid -> structure solutions /solu physics,read,fluid ! Read in fluid environment *if,i,ne,1,then flda,iter,exec,100 ! Execute 100 global iterations for *endif ! each new geometry solve ! FLOTRAN solution fini ! end of fluid portion physics,read,struc ! Read in structures environment /assign,esave,struc,esav ! Files for restarting nonlinear structure /assign,emat,struc,emat *if,i,gt,1,then ! Structural restart loop parsave,all ! Save parameters for convergence check resume ! Resume DB - to return original node positions parresume ! Resume parameters needed for convergence check /prep7 antype,stat,rest fini *endif /solu solc,off lsel,s,,,1,3,2 ! Select proper lines to apply fluid pressures lsel,a,,,6 ! to the entire gasket surface nsll,,1 esel,s,type,,2 ldread,pres,last,,,,,rfl ! Apply pressure surface load from Flotran

alls rescontrol,,none solve *if,i,eq,1,then save *endif fini

! Do not use multiframe restart for nonlinear

! save original node locations at the first run

/post1 cmsel,s,gasket nsort,u,sum,1,1 *get,dismax(i),sort,0,max ! Get the maximum displacement value strcri(i)=toler*dismax(i) alls fini /prep7 mkey=2 ! Select level of mesh morphing for fluid damorph,area2, ,mkey ! Perform morphing of "morphing fluid" !---------------!!!!! Create element plot and write it in file gasket.grph fini /prep7 et,1,42 asel,s,,,1,3 esla,s /Title, EPLOT after DAMORPH,area2, ,%mkey% step number %i% eplot alls !----------------cmsel,s,gasket nlist ! List updated coordinates of bottom of gasket for comparison /com, +++++++++ UPDATED gasket coordinates -------alls fini /assign,esav /assign,emat !!!! Checking convergence criteria imax= i index(i)=i *if,i,gt,1,then strcri(i)=abs(dismax(i)-dismax(i-1))-toler*dismax(i-1) *if,strcri(i),le,0,then

strcri(i)=0 *exit ! Stop looping if convergence is reached *endif *endif *enddo !!!!! End of the Computational loop save ! Nodal coordinates of deformed geometry are saved !!!!! Convergence printout *vwrite (/'Loop No. Max.Displacement Struct.Convergence') /nopr *vlen,imax *vwrite,index(1),dismax(1),strcri(1) (f7.0,2e17.4) finish !!!!! Postprocessing of the results !!! 1. Flotran results. physics,read,fluid /post1 set,last /Title, Flotran: Streamlines Near Gasket plnsol,strm /Title, Flotran: Pressure Contours plnsol,pres fini !!! 2. Structural results. physics,read,struc /post1 set,last upcoord,-1 ! Return original node positions changed by morphing /Title, Structural results: von Mises Stress plnsol,s,eqv,1,1 fini 讲解: 橡胶垫在流体作用下发生变形,变形又反过来影响流体形状,例子中设定的流固区,在流体 分析和固体分析中都作为分析对象, 在结构分析中求解流固区可得到网格的变形, 用于流场 分析,此区域在流体物理环境中赋予流体属性,在结构物理环境中附于结构属性,这一点是 说允许由于橡胶垫变形引起网格变形。 纯流体区域仅在流体物理环境中使用, 橡胶垫也只在 结构物理环境中使用。 三个区分别是 固体区--橡胶垫;流体区;流固区 流体区域编号一定要设为 1

在创建流体环境时,流体和流固两区分配流体属性,此时固体区,也就是橡胶垫为 null,设 定好之后将流体物理环境写入物理环境文件。 然后清除流体物理环境, 定义结构物理环境, 此时流体区域为 null, 定义载荷步和求解选项, 写入流体物理环境。 最后 流/固求解循环! 给大家推荐一本讲解流固耦合的书,感觉还不错! 张立翔,杨柯. 《流体结构互动理论及其应用》科学出版社。2004.3

再给大家推荐一本:居荣初,曾心传。 《弹性结构与液体的耦联振动理论》 地震出版社,1983

针对液面晃动问题,ANSYS/LS-DYNA 提供以下三种方法: 1、 流固耦合 流固耦合是 ANSYS/LS-DYNA 计算流体和结构间相互作用的最常用的方法,包括单物质+ 空材料和多物质耦合两大类,流体单 元有 Euler 和 ALE 两种。其涉及的主要命令如下: *control_ale 算法选择有两种 2、3,分别为 Euler 和 ale 实质上此处二者没有区别,只是因为兼容性进行 的设置;两种精度供选择-单精度 、双精度。 *section_solid_ale 对单物质+空材料为 12 号算法,对多物质耦合为 11 号算法。 *ale_multi-material_group 进行多物质的定义,最多可以定义 20 种材料。可以根据物质间能否混合将各种材料定义在 不同的材料组 ID 中。 * ale_multi-material_system_group 该命令决定流体物质的算法(Euler 或 Ale) ,或是在运算过程中切换使用两种算法,并可对 流体物质进行自由度约束。该命 令多与下列三个命令结合使用: * ale_multi-material_system_curve 定义 ale 系统的运动曲线。 * ale_multi-material_system_node 通过一系列节点定义 ale 的运动参考坐标系统。 * ale_multi-material_system_switch 定义 euler 和 ale 参考系统的切换。 上述命令是流体物质涉及的关键字,而我们知道,结构采用 Lagrange 单元来离散,二者之 间的耦合通过下列命令来实现:

*constrained_lagrange_in_solid 耦合算法分为两种:罚耦合和运动约束。前者遵循能量守恒,后者遵循动量守恒。一般令结 构网格较流体网格密以保证界面 不出现渗透, 否则可以增大 NQUAD 参数值来增加耦合点, 如设置该值为 4 或 5。 970 中, 在 此命令第三行又增加了一个控制字 ILEAK-0,1 或 2,一般可设置为 1。 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 2222 $===================================================================== === $ [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

11110000 *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 21110000 *INITIAL_VOID_PART 2 $===================================================================== === *PART rigid box containing water $ PID SECID MID EOSID HGID GRAV ADPOPT TMID 33300000 *SECTION_SOLID $ SECID ELFORM AET 30 *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 444 *SECTION_SHELL $ SID ELFORM SHRF NIP PROPT QR/IRID ICOMP 40

$ 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 3433 $ 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 1051 $ XC YC ZC EXPLIM *SET_PART_LIST $ SID DA1 DA2 DA3 DA4 1 $ PID1 PID2 PID3 PID4 PID5 PID6 PID7 PID8 12 *ALE_REFERENCE_SYSTEM_NODE $ NSID 1 $ N1 N2 N3 N4 N5 N6 N7 N8 567

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 $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ CONTROL OPTIONS $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ *CONTROL_PARALLEL 1 *CONTROL_ENERGY 2222 *CONTROL_SHELL 20.0 1 -1 1 2 2 1 *CONTROL_TIMESTEP 0.0000 0.9000 0 0.00 0.00 *CONTROL_TERMINATION $1000.0000 0 0.00000 0.00000 0.00000 0.800E+05 0 0.00000 0.00000 0.00000 *CONTROL_SPH 20 $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ TIME HISTORY $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ *DATABASE_BINARY_D3PLOT 200.0E+00 $0.500E+00 *DATABASE_BINARY_D3THDT 0.8000E+02 *DATABASE_EXTENT_BINARY

00310000 004000 $ $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ SECTION DEFINITIONS $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ *SECTION_SOLID 21 *SECTION_SPH 1 $ $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ MATERIAL DEFINITIONS $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ *MAT_RIGID 2 7.80 2.10 0.300000 0.0 0.0 0.0 1.00 7.00 7.00 *MAT_RIGID 3 7.80 2.10 0.300000 0.0 0.0 0.0 1.00 6.00 7.00 *MAT_RIGID 4 7.80 2.10 0.300000 0.0 0.0 0.0 1.00 6.00 7.00 *MAT_NULL 1 1.00 *EOS_GRUNEISEN 1 .1484000 1.9790000 .0000000 .0000000 .1100000 3.0000000 .0000000 .0000000 $ $ $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $

$ PARTS DEFINITIONS $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ $ *PART Part 1 for Mat 4 and Elem Type 1 1111000 $ *PART Part 2 for Mat 2 and Elem Type 1 2220000 $ *PART Part 3 for Mat 3 and Elem Type 1 3230000 *PART Part 3 for Mat 3 and Elem Type 1 4240000 $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ RIGID BOUNDRIES $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ *LOAD_BODY_Y 2,1.0 *DEFINE_CURVE 2 0.0,9.8E-10 1.0,9.8E-10 $ *DEFINE_CURVE 1 0 1.000 1.000 0.000 0.000 0.000000000000E+00 1.000000000000E-04 1.000000000000E+05 1.000000000000E-04 *BOUNDARY_PRESCRIBED_MOTION_RIGID 3 2 0 1 -1.00 0 0.000 0.000 $ $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ NODE DEFINITIONS $

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ *CONTACT_AUTOMATIC_NODES_TO_SURFACE 11320000 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

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: ALE 网格要进行滑顺处理, 对 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 2222 *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 0000 *CONTROL_TERMINATION 0.100E+05 0 0.00000 0.00000 0.00000 $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ TIME HISTORY $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ *DATABASE_BINARY_D3PLOT 0.1000E+03 *DATABASE_BINARY_D3THDT 0.1000E+02 *DATABASE_EXTENT_BINARY 00310000 004000 $ $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ SECTION DEFINITIONS $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ *SECTION_SOLID 21 *SECTION_SOLID_ALE 15 $ $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ MATERIAL DEFINITIONS $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ *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 $ $ $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ PARTS DEFINITIONS $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ $ *PART Part 1 for Mat 4 and Elem Type 1 1111000 $ *PART Part 2 for Mat 2 and Elem Type 1 2220000 $ *PART Part 3 for Mat 3 and Elem Type 1 3230000 *PART Part 3 for Mat 3 and Elem Type 1 4240000 $ $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ RIGID BOUNDRIES $

$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$ $ $ *CONTACT_SURFACE_TO_SURFACE 12330000 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 13330000 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 14330000 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。 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 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

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 *** ERROR *** 时,出现了这样的错误 CP= 29.297 TIME= 22:15:44 Number of FLUID/SOLID interfaces do not match for FSIN boundary

condition. *** ERROR *** CP= 29.641 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 fsco,all,1.0e-1 fsre,all,0.5 fsou,1 !FSI analysis on !FSI convergence criteria !FSI relaxation !FSI output frequency TIME= 22:15:48

fsit,5 fsti,0.05 fsdt,0.01 fsor,fluid fstr,solid, fstr,fluid, deltim,0.01 fldata,time,step,0.01 save

!Number of stagger loops !FSI end time !FSI delta time !FSI order of solution !Transient fluid for FSI analysis !Transient structural for FSI analysis

网上找到的 水坝空库 /BATCH KEYW,PR_SET,1 KEYW,PR_STRUC,1 KEYW,PR_THERM,0 KEYW,PR_FLUID,0 KEYW,PR_ELMAG,0 KEYW,MAGNOD,0 KEYW,MAGEDG,0 KEYW,MAGHFE,0 KEYW,MAGELC,0 KEYW,PR_MULTI,0 KEYW,PR_CFD,0 /GO !* /prep7 !* define material proterties mp,dens,1,2650. !mat 1 for dam mp,ex,1,3.15e10 mp,prxy,1,.167

!* define element type et,1,PLANE42,,,2

!* define geometry lwater=618.

k, 1,0.0,0.0,0.0 k, 2,70.2,0.,0. k, 3,0.,66.5,0. k, 4,21.9875,66.5,0. k, 5,0.,103.,0. k, 6,14.8,103.,0.

a, 1, 2, 4, 3 a, 3, 4, 6, 5

asel,s,loc,x,0.,100. aatt,1,,1 cm,adam,area

allsel,all !* mesh geometry ESIZE,0,10 lsel,s,loc,y,0.1,66. lesize,all,,,15 mshape,0,2D mshkey,1 allsel,all amesh,all finish /solu antype,modal MODOPT,LANB,30 MXPAND,30, , ,0

!坝下部剖分分数

esel,s,mat,,1 nsle,s nsel,r,loc,y,-1.0,1.0 d,all,ux,0. d,all,uy,0.

!坝体约束

/pbc,all,,1 /pnum,type,1 /number,1 gplot

allsel,all save

满库 /BATCH KEYW,PR_SET,1 KEYW,PR_STRUC,1 KEYW,PR_THERM,0 KEYW,PR_FLUID,0 KEYW,PR_ELMAG,0 KEYW,MAGNOD,0 KEYW,MAGEDG,0 KEYW,MAGHFE,0 KEYW,MAGELC,0 KEYW,PR_MULTI,0 KEYW,PR_CFD,0 /GO !* /prep7 !* define material proterties mp,dens,1,2650. !mat 1 for dam mp,ex,1,3.15e10 mp,prxy,1,.167 mp,dens,2,1000. !mat 2 for water mp,sonc,2,1440 !* define element type et,1,PLANE42,,,2 et,2,29 et,3,29,,1

!* define geometry

lwater=618. k, 1,0.0,0.0,0.0 k, 2,70.2,0.,0. k, 3,0.,66.5,0. k, 4,21.9875,66.5,0. k, 5,0.,103.,0. k, 6,14.8,103.,0. k, 7,-1.*lwater,103.,0. k, 8,-1.*lwater,66.5,0. k, 9,-1.*lwater,0.,0.

a, 1, 2, 4, 3 a, 3, 4, 6, 5 a, 8, 3, 5, 7 a, 9,1, 3, 8 asel,s,loc,x,0.,100. aatt,1,,1 cm,adam,area asel,s,loc,x,-1*lwater,0. aatt,2,,3 cm,awater,area allsel,all !* mesh geometry ESIZE,0,10 lsel,s,loc,y,0.1,66. lesize,all,,,15 lsel,s,loc,x,-0.1,-1*lwater-1. lsel,r,loc,y,-0.1,67. lesize,all,,,40,0.5 lsel,s,loc,x,-0.1,-1*lwater-1. lsel,r,loc,y,100.,104. lesize,all,,,40,2.0 mshape,0,2D mshkey,1 allsel,all amesh,all !更改与水体接触的单元类型 esel,s,type,,3

!坝下部剖分分数 !水体长度方向剖分分数

!水体长度方向剖分分数

nsle,s nsel,r,loc,x,-1.,1. esln,r emodif,all,type,2 allsel,all finish /solu antype,modal MODOPT,UNSYM,30 MXPAND,30, , ,0 /pnum,type,1 /number,1 nsel,s,loc,x,-1.,1. esln,s esel,r,mat,,2 sf,all,fsi esel,s,mat,,1 nsle,s nsel,r,loc,y,-1.0,1.0 d,all,ux,0. d,all,uy,0. esel,s,mat,,2 nsle,s nsel,r,loc,y,102.,104. d,all,pres,0. /pbc,all,,1 /psf,fsi,,2 allsel,all gplot save !库水坝体 FSI 面

!坝体约束

!水体表面约束


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