电磁场，求鉴定

我做了个例子，就是通过线圈在钢板上才生涡流，可悲的是磁力线都通过钢板了，为什么呢？高手们给个解释。下面是命令流
/title,voltage-fed thick stranded coil in free space
/filnam,vol_coil_2d,1
keyw,magnod,1
/prep7
*SET,r,0.025
*SET,s,0.005
*set,n,91
*set,sigma,5.0e6
Et,1,53,,,1
!钢板和空气单元
Et,2,53,2,,1
!线圈单元，自由度AZ-CURR
Emunit,mks
Mp,murx,1,1
Mp,murx,2,1
!线圈材料号及相对磁导率
Mp,rsvx,2,3.00 e-8
Mp,murx,3,5000
!钢板材料号及相对磁导率
Mp,rsvx,3,1/sigma
!钢板电阻率
*DO,I,0,19,1
Rectng,r+1.2* s*I,r+s+1.2*s*I,0,s
*ENDDO
!创建20个线圈
Rectng,0,6.5*r,0.01+s,0.012+s
!钢板模型
Rectng,0,8*R,0,0.2
!空气模型
Aovlap,all
*do,i,1,20,1
Asel,s,area,,i
Aatt,2,1,2
*enddo
!选择线圈面及分配属性
Asum
*get,a,area,,area
!得线圈横截面积
ASEL,S,AREA,,23
AATT,1,1,1
!空气分配属性
ASEL,S,AREA,,21
!给钢板分配属性
AATT,3,1,1
Asel,all
Esize,,8
*do,I,1,20,1
Mshape,0,2d
Mshky,1
AMESH,I
*enddo
Esize,S/2
Mshape,0,2D
Mshkey,1
Amesh,21
Smrtsize,8
Esize,s/2
Mshape,1,2D
Mshkey,0
Amesh,23
*DO,I,1,20
R,I,2*a,91,,1,1
*ENDDO
ESEL,S,MAT,,2
Nsle,s
CP,1,CURR,ALL
ALLSEL,ALL
Nsel,s,loc,x,0
D,all,az,0
Allsel,all
Finish
/solu
Antype,harm
Esel,s,mat,,2
Bfe,all,vltg,,800
Esel,all
Harfrq,20000
Solve
Finish
/post1
Set,1
Plf2d
*get,curreal,node,n1,curr
Set,1,1,,1
Plf2d