ansys16.0版本中如何实现网格划分有密有疏的效果？

 一、试验桩概况及拟实现的网格效果

  本次将对文献Uplift behaviour of helical anchors in clay（WANG,D)中的试验螺旋桩C1进行网格划分，其尺寸如下：杆轴长9.85m，直径0.4m，有三个螺旋板，直径均为2.4m，从顶到底螺旋板离地表的距离分别为2.65m、6.25m、9.85m，螺旋板间距3.6米，板间距与直径比为1.5。在螺旋桩螺旋板半径范围内的土体尺寸较密，远离桩体的边界附近土体较疏，中间逐渐增大，效果如下：

二、使用的功能

1、Refining a Mesh Locally

    For all area meshes and for volume meshes composed of tetrahedra, the ANSYS program allows you to refine the mesh locally around specified nodes, elements, keypoints, lines, or areas. Meshes composed of volume elements other than tetrahedra (for example, hexahedra, wedges, and pyramids) cannot be locally refined.除了四面体单元外，其他单元（如六面体、楔形和金字塔等）均不能进行局部加密。

2、Restrictions on Mesh Refinement

1）If the model contains contact elements in the region selected to refine, you cannot use local mesh refinement. In this case, refine the mesh before defining contact elements (or, delete the contact elements, refine the mesh, then reapply the contact elements).

2）Local mesh refinement cannot be done if initial conditions at nodes [IC], coupled nodes [CP family of commands], or constraint equations [CE family of commands] exist in the model. If any of these exist, you must remove them before refinement can be done.

 

三、操作步骤

1、命令流（文件名WANG D-c1 20151005.txt)

/batch,list                         !Sets the program mode to "batch." so that the log file can be reused later for batch input.
/config,nproc,1                     !Assigns values to ANSYS configuration parameters.
/PREP7
!-----------geometry parameters--------------- !mm

!---------inital meshing parameters------------
soil_esize  = 400   
shaft_esize  = 400   
!------------loading parameters----------------
shaft_disp  = -800  
!------------NLAD parameters------------------
skw_   = 0.9      !skewness threshold
freq   = 1       !NLAD frequency (1 means check every substep)
start_time  = 0      !beginning time for NLAD interval
end_time  = 1       !end time for NLAD interval
!------------remeshing parameters---------------
sculpt_layers = 2      !number of sculpting layers
conc_   = 10       !concave patch splitting angle           

    
conv_   = 10       !convex patch splitting angle
edge_   = 10       !edge splitting angle

!---------element types & settings-----------
et,1,285                                  ! for soil
       
et,2,285                                  ! for shaft

*do,i,3,19,2
et,i,170
*enddo

*do,i,4,20,2
et,i,173
*enddo

!******************material properties*****************
MP,EX,1,10.375        !soil material properties             
MP,NUXY,1,0.49               !poisson's ratio           
TB,BISO,1,1                                                  !bilinear isotropic material
TBDATA,1,0.024        !yield stress in MPa
TBDATA,2,0.01        !tangent modulus in MPa

MP,EX,2,10e6        !steel material properties             
MP,NUXY,2,0.3               !poisson's ratio           

*do,i,3,15,1                                                            !contact 摩擦系数                                                     
mp,mu,i,0.2
*enddo

!------------geometry creation-------------------
CYL4, , , , ,200,90 ,-2650                                         
!杆轴的第一个1/4圆柱，半径为200mm，第一段长度为2650mm。变模型时参数需修改                                                                  
!Creates a circular area or cylindrical volume anywhere on the working plane.                                                                  
!CYL4, XCENTER, YCENTER, RAD1, THETA1, RAD2, THETA2, DEPTH                        

WPAVE,,,-2650                                                      
!Moves the working plane origin to the average of specified points.变模型时参数需修改
CYL4, , , , ,1200,90,-72                                           
!第一个螺旋板的1/4圆柱，半径为1200mm，厚度为72mm；变模型时参数需修改

WPAVE,,,-2722                                                     
!Moves the working plane origin to the average of specified points.变模型时参数需修改，2722=2650+72
CYL4, , , , ,200,90 ,-3528                                          
!杆轴的第二个1/4圆柱，半径为200mm，第二段长度为3528=3600-72mm。 变模型时参数需修改

WPAVE,,,-6250                                                     
!Moves the working plane origin to the average of specified points.变模型时参数需修改 6250=2722+6250
CYL4, , , , ,1200,90,-72                                           
!第二个螺旋板的1/4圆柱，半径为1200mm，厚度为72mm；变模型时参数需修改

WPAVE,,,-6322                                                     
!Moves the working plane origin to the average of specified points.变模型时参数需修改，6322=6250+72
CYL4, , , , ,200,90 ,-3528                                          
!杆轴的第三个1/4圆柱，半径为200mm，第三段长度为3528=3600-72mm。 变模型时参数需修改

WPAVE,,,-9850                                                     
!Moves the working plane origin to the average of specified points.变模型时参数需修改 9850=6322+3528
CYL4, , , , ,1200,90,-72                                          
!第三个螺旋板的1/4圆柱，半径为1200mm，厚度为72mm；变模型时参数需修改

CM,SHAFTPLATE01,VOLUM                                              
!将所有杆轴几何体建立一个组

WPAVE,,,0                                                          
!Moves the working plane origin to the average of specified points.变模型时参数需修改
CYL4, , , , ,4000,90,-19700                                        
!桩周土体1/4圆柱，半径为4000mm，厚度为19700mm；体编号为7，变模型时参数需修改

CMSEL,S,SHAFTPLATE01                     
VGEN,2,ALL, , , , , , ,0                                           
!将杆轴与螺旋板原位复制，以便后续布尔运算
CMSEL,NONE                                                         
!NONE--Unselect all components
CM,SHAFTPLATE02,VOLUM                                              
!将复制出来的另建立为一组
ALLSEL

VSBV,       7,       SHAFTPLATE02                                                
!布尔运算, 变模型时参数需修改
VSEL,S, , ,      14                                                                        
!土体几何体编号由原来的7变为14, 变模型时参数需修改

CMSEL,S,SHAFTPLATE01
VGLUE,ALL                                                          
!合并所有钢构件的重叠线段与面积

CM,SHAFTPLATE01,VOLUM                                              
!将所有杆轴几何体建立一个组
                                                         
ALLSEL

!-------------soil meshing----------------
type,1
mat,1         
real,1          
esize,soil_esize
vmesh,14            !变模型时参数需修改
ALLSEL

!-------------steel meshing----------------
type,2
mat,2         
real,2          
esize,shaft_esize
vmesh,SHAFTPLATE01
ALLSEL

 

!-------------remeshing----------------
CMSEL,S,SHAFTPLATE01
ASLV,S
AREFINE,ALL, , ,1,0,1,1     !第一个1代表1/2
ALLSEL

SELTOL,1.0E-8

VSEL,S, , , 14
ESLV,S
NSLE,S 
CSYS,1
NSEL,R,LOC,X,0,1300
NSEL,U,LOC,Z,-10000,-20000
ESLN,S
CSYS,0
EREF,ALL, , ,1,0,1,1

ALLSEL
!----------
!VSEL,S, , , 14
!ASLV,S
!CSYS,1
!ASEL,U,LOC,X,3900,4100
!ASEL,U,LOC,X,1500,4100
!CSYS,0
!AREFINE,ALL, , ,1,0,1,1 
!仅对与螺旋杆与板面接触的面进行了细分，其他区域土体单元有畸变，无法求救
!ALLSEL
!-------------contact pair R3----------------
real,3
mat,3                    
!-----target elements-------
type,3
!选择第一个螺旋板底面并在上建立target接触
CMSEL,S,SHAFTPLATE01
ASLV,S
ASEL,R,LOC,Z,-2722    !变模型时参数需修改
ASEL,U,LOC,X,0,100    !变模型时参数需修改
!剔掉杆轴面 
nsla,s,1
esln
esurf
alls
!----contact elements-------
type,4 
!选择第一个螺旋板下土体面并在上建立contact接触
VSEL,S, , , 14
ASLV,S
ASEL,R,LOC,Z,-2722   
nsla,s,1
esln
esurf
alls

!-------------contact pair R4----------------
real,4
mat,4                    
!----target elements-------
type,5
!选择第2个螺旋板底面并在上建立target接触
CMSEL,S,SHAFTPLATE01
ASLV,S
ASEL,R,LOC,Z,-6322     !变模型时参数需修改
ASEL,U,LOC,X,0,100    !变模型时参数需修改
!剔掉杆轴面
nsla,s,1
esln
esurf
alls
!--contact elements-----
type,6
!选择第2个螺旋板下土体面并在上建立contact接触
VSEL,S, , , 14
ASLV,S
ASEL,R,LOC,Z,-6322    
nsla,s,1
esln
esurf
alls

!-------------contact pair R5----------------
real,5
mat,5                    
!----target elements-------
type,7
!选择第3个螺旋板底面并在上建立target接触
CMSEL,S,SHAFTPLATE01
ASLV,S
ASEL,R,LOC,Z,-9922     !变模型时参数需修改
!ASEL,U,LOC,X,0,100    !变模型时参数需修改
!无需剔掉杆轴面
nsla,s,1
esln
esurf
alls
!--contact elements-----
type,8
!选择第3个螺旋板下土体面并在上建立contact接触
VSEL,S, , , 14
ASLV,S
ASEL,R,LOC,Z,-9922    
nsla,s,1
esln
esurf
alls

!-------------contact pair R6----------------
real,6
mat,6                    
!-----target elements-------
type,9
!选择第一个螺旋板顶面并在上建立target接触
CMSEL,S,SHAFTPLATE01
ASLV,S
ASEL,R,LOC,Z,-2650    !变模型时参数需修改
ASEL,U,LOC,X,0,100    !变模型时参数需修改
!剔掉杆轴面 
nsla,s,1
esln
esurf
alls
!----contact elements-------
type,10 
!选择第一个螺旋板顶土体面并在上建立contact接触
VSEL,S, , , 14
ASLV,S
ASEL,R,LOC,Z,-2650   
nsla,s,1
esln
esurf
alls

!-------------contact pair R7----------------
real,7
mat,7                    
!----target elements-------
type,11
!选择第2个螺旋板顶面并在上建立target接触
CMSEL,S,SHAFTPLATE01
ASLV,S
ASEL,R,LOC,Z,-6250     !变模型时参数需修改
ASEL,U,LOC,X,0,100    !变模型时参数需修改
!剔掉杆轴面
nsla,s,1
esln
esurf
alls
!--contact elements-----
type,12
!选择第2个螺旋板顶土体面并在上建立contact接触
VSEL,S, , , 14
ASLV,S
ASEL,R,LOC,Z,-6250     
nsla,s,1
esln
esurf
alls

!-------------contact pair R8----------------
real,8
mat,8                    
!----target elements-------
type,13
!选择第3个螺旋板顶面并在上建立target接触
CMSEL,S,SHAFTPLATE01
ASLV,S
ASEL,R,LOC,Z,-9850     !变模型时参数需修改
ASEL,U,LOC,X,0,100    !变模型时参数需修改
!剔掉杆轴面
nsla,s,1
esln
esurf
alls
!--contact elements-----
type,14
!选择第3个螺旋板顶土体面并在上建立contact接触

SELTOL,1.0E-8
VSEL,S, , , 14
ASLV,S
ASEL,R,LOC,Z,-9850

CSYS,1
!ASEL,R,LOC,Y,0,200    !很奇怪选不到
ASEL,U,LOC,X,3900,4100   
nsla,s,1
esln
esurf
alls

CSYS,0

!-------------contact pair R9----------------
real,9
mat,9                    
!-----target elements-------
type,15
!选择第一个螺旋板侧面并在上建立target接触
CMSEL,S,SHAFTPLATE01
ASLV,S

ASEL,R,LOC,Z,-2650,-2722   !变模型时参数需修改
CSYS,1
ASEL,R,LOC,X,1200          !变模型时参数需修改 
nsla,s,1
esln
esurf
alls
CSYS,0

!----contact elements-------
type,16 
!选择第一个螺旋板侧土体面并在上建立contact接触
VSEL,S, , , 14
ASLV,S

ASEL,R,LOC,Z,-2650,-2722 
!ASEL,R,LOC,X,1200             !很奇怪选不到

CSYS,1
ASEL,U,LOC,X,0,1100
CSYS,0
nsla,s,1
esln
esurf
alls

!-------------contact pair R10----------------
real,10
mat,10                    
!----target elements-------
type,17
!选择第2个螺旋板侧面并在上建立target接触
CMSEL,S,SHAFTPLATE01
ASLV,S

ASEL,R,LOC,Z,-6250,-6322   !变模型时参数需修改
CSYS,1
ASEL,R,LOC,X,1200   !变模型时参数需修改
CSYS,0           
nsla,s,1
esln
esurf
alls

!--contact elements-----
type,18
!选择第2个螺旋板侧土体面并在上建立contact接触
VSEL,S, , , 14
ASLV,S

ASEL,R,LOC,Z,-6250,-6322 
!ASEL,R,LOC,X,1200             !很奇怪选不到

CSYS,1
ASEL,U,LOC,X,0,1100
CSYS,0
nsla,s,1
esln
esurf
alls

!-------------contact pair R11---------------
real,11
mat,11                    
!----target elements-------
type,19
!选择第3个螺旋板侧面并在上建立target接触
CMSEL,S,SHAFTPLATE01
ASLV,S

ASEL,R,LOC,Z,-9850,-9922   !变模型时参数需修改
CSYS,1
ASEL,R,LOC,X,1200   !变模型时参数需修改
CSYS,0           
nsla,s,1
esln
esurf
alls

!--contact elements-----
type,20
!选择第3个螺旋板侧土体面并在上建立contact接触
VSEL,S, , , 14
ASLV,S

ASEL,R,LOC,Z,-9850,-9922 
!ASEL,R,LOC,X,1200             !很奇怪选不到

CSYS,1
ASEL,U,LOC,X,0,1100
ASEL,U,LOC,X,3900,4100
CSYS,0
nsla,s,1
esln
esurf
alls
!--------------create components-----------
ESEL,S,MAT,,1
cm,comp1,elem    !make whole soil as NLAD component
alls
!-----boundary conditions & loading------- 
/SOL
ASEL,S,LOC,X,0
DA,ALL,SYMM           !施加对称约束
alls

ASEL,S,LOC,Y,0
DA,ALL,SYMM           !施加对称约束
alls

ASEL,S,LOC,Z,-19700
DA,ALL,ALL           !施加土底约束
alls

CSYS,1
VSEL,S, , , 14
ASLV,S
ASEL,R,LOC,X,3900,4100
DA,ALL,ALL           !施加土边界约束
CSYS,0
alls

CMSEL,S,SHAFTPLATE01
ASLV,S
ASEL,R,LOC,Z,0
da,all,uz,shaft_disp
alls
finish

/SOLU                        
!--------------general solution settings--------
nlgeom,on     !Includes large-deflection effects in a static or full transient analysis.
eresx,no      !Specifies extrapolation of integration point results.
outres,all,all
!---------------NLAD settings-------------------
!check NLAD parameters section above for values

nlad,comp1,add,mesh,skew,skw_          !nlad with mesh distortion criterion
!Defines the criteria under which the mesh is refined or modified during a nonlinear solution.
!NLADAPTIVE, Component, Action, Criterion, Option, VAL1, VAL2, VAL3

nlad,comp1,on,,,freq,start_time,end_time       
!------------remeshing settings---------------
!check remeshing parameters section above for values
nlad,comp1,nlay,sculpt_layers
nlad,comp1,nang,conc_,conv_
nlad,comp1,aedg,edge_

!---------------step settings-------------------
time,1 
nsubst,100,10000,10

alls
solve
finish

 

2、上述算例说明