平板聲學分析Ansys
具體計算結果見附件
下面是程序清單：
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/PREP7
ET,1,SOLID45 !殼單元 類型1
ET,2,FLUID30 ! acoustic fluid element with ux & uy(0-Structure present at interface (unsymmetric element matrix))
ET,3,130 ! acoustic infinite line element
r,3,0.3,0,0
ET,4,FLUID30,,1,0 ! acoustic fluid element without ux & uy(1-No structure at the interface (symmetric element matrix))
! material properties
!材料1為鐵
MP,EX,1,2.1E11
MP,DENS,1,7800
MP,NUXY,1,0.3
!材料2為空氣介質
MP,DENS,2,1.21
MP,SONC,2,344
!建立模型
wprot,0,-90,0
SPHERE,,0.3,0,180 !SPHERE, RAD1, RAD2, THETA1, THETA2
wprot,0,90,0
BLOCK,0,0.1, -0.002, 0.002, -0.1, 0 !BLOCK, X1, X2, Y1, Y2, Z1, Z2
BLOCK,-0.1,0, -0.002, 0.002, -0.1, 0
VGLUE,2,3
VOVLAP,1,2 !Overlaps volumes
VOVLAP,3,4
!對編號為2的體劃分網格
lesize,9,,,20,1
lesize,19,,,20,1
lesize,14,,,20,1
lesize,18,,,20,1
lesize,11,,,20,1
lesize,16,,,20,1
lesize,12,,,20,1
lesize,17,,,20,1
lesize,8,,,4,1
lesize,15,,,4,1
lesize,13,,,4,1
lesize,10,,,4,1
VSEL,s,,,2
VATT,1,,1
mshkey,1 !Specifies whether free meshing or mapped meshing should be used to mesh a model.1— Use mapped meshing.
VMESH,2
alls
!對編號為4的體劃分網格
lesize,32,,,20,1
lesize,31,,,20,1
lesize,35,,,20,1
lesize,33,,,20,1
lesize,28,,,20,1
lesize,34,,,20,1
lesize,20,,,4,1
lesize,27,,,4,1
VSEL,s,,,4
VATT,1,,1
mshkey,1 !Specifies whether free meshing or mapped meshing should be used to mesh a model.1— Use mapped meshing.
VMESH,4
alls
!對編號為1的體劃分網格(此步驟劃分網格需要手動進行)
VSEL,s,,,1
VATT,2,,2 !指定的材料屬性為空氣介質(與結構耦合)
SMRT,1
VMESH,1
alls
!修改不與平板（結構）接觸單元的材料類型類型為空氣介質（不與結構耦合）
esel,s,type,,1
nsle,s
esln,s,0
nsle,s
esel,inve
nsle,s
emodif,all,type,4
alls
!在邊界生成吸收單元。（使用單元fluid130）
Asel,s,,,1,2
NSLA,S,1
type,3
real,3
mat,2
esurf !Generates elements overlaid on the free faces of existing selected elements.
alls
!建立流－固接觸面
Asel,s,,,8
Asel,A,,,10
Asel,A,,,7
Asel,A,,,5
Asel,A,,,19
Asel,A,,,15
Asel,A,,,17
Asel,A,,,20
NSLA,S,1
esel,s,type,,2
sf,all,fsi,1
alls
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!第一種后處理方式，得到空氣介質的聲壓分布，單位為分貝
/solu
antype,harmic
hropt,full
f,131,fY,1000.
alls
nsubst,10
kbc,1
HARF,337,337 !加載80Hz的頻率
SOLVE
!對與結構耦合的空氣單元和未與結構耦合的空氣單元進行后處理，得到聲壓分布
/post1
SET,FIRST
esel,s,type,,2
esel,a,type,,4
PLESOL, NMISC,4, 0,1.0
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!第二種分析后處理方式，
!使用諧波分析法對530－540Hz頻率之間進行頻率掃描計算第一階彎曲模態，從而檢測到結構模型的固有頻率
/solu
antype,harmic
hropt,full
f,131,fY,1000.
alls
nsubst,10
kbc,1
HARF,530,540 !加載頻率530－540
SOLVE
!檢測到結構模型的固有頻率
/post26
plcplx,0
nsol,2,1,u,x,d1ux
store
conjug,3,2
prod,4,2,3
sqrt,5,4
*get,uxmx,vari,5,extrem,tmax
/COM -------------------------------------------------------------
/COM Expected Result:
/COM
/COM The following "uxmx" should equal
/COM -------------------------------------------------------------
*status,uxmx
finish