做弹簧划分网格.doc

hekie
做弹簧划分网格

如题
bigbird在台湾论坛上的题目，下图是我做的，感觉有意思。
做出部分也可以上传，积分鼓励

大家思考一下，试着做一下
可以提示一下
先造线，再由面沿线生成体

雨人

我在HELP中COPY的一点有关内容，与该题有关，希望和我一样

没用过该命令的同学，看过后，都能试着做一下。我也在试着做。

我想这个命令做螺纹时同样适用。

    VEXT, NA1, NA2, NINC, DX, DY, DZ, RX, RY, RZ — Generates additional volumes by extruding areas.

PREP7:Volumes

MP ME ST DY PR EM EH FL PP ED

NA1, NA2, NINC
Set of areas (NA1 to NA2 in steps of NINC) that defines the pattern to be extruded. NA2 defaults to NA1, NINC defaults to 1. If NA1 = ALL, NA2 and NINC are ignored and the pattern is defined by all selected areas. If NA1 = P, graphical picking is enabled and all remaining command fields are ignored (valid only in the GUI). A component name may also be substituted for NA1 (NA2 and NINC are ignored).

DX, DY, DZ
Increments to be applied to the X, Y, and Z keypoint coordinates in the active coordinate system (DR, Dθ, DZ for cylindrical; DR, Dθ, DΦ for spherical).

RX, RY, RZ
Scale factors to be applied to the X, Y, and Z keypoint coordinates in the active coordinate system (RR, Rθ, RZ for cylindrical; RR, Rθ, RΦ for spherical). Note that the Rθ and RΦ scale factors are interpreted as angular offsets. For example, if CSYS = 1, RX, RY, RZ input of (1.5,10,3) would scale the specified keypoints 1.5 times in the radial and 3 times in the Z direction, while adding an offset of 10 degrees to the keypoints. Zero, blank, or negative scale factor values are assumed to be 1.0. Zero or blank angular offsets have no effect.

Notes
Generates additional volumes (and their corresponding keypoints, lines, and areas) by extruding and scaling a pattern of areas in the active coordinate system.

If element attributes have been associated with the input area via the AATT command, the opposite area generated by the VEXT operation will also have those attributes (i.e., the element attributes from the input area are copied to the opposite area). Note that only the area opposite the input area will have the same attributes as the input area; the areas adjacent to the input area will not.

If the areas are meshed or belong to meshed volumes, a 3-D mesh can be extruded with this command. Note that the NDIV argument on the ESIZE command should be set before extruding the meshed areas.

Scaling of the input areas, if specified, is performed first, followed by the extrusion.

In a non-Cartesian coordinate system, the VEXT command locates the end face of the volume based on the active coordinate system. However, the extrusion is made along a straight line between the end faces. Note that solid modeling in a toroidal coordinate system is not recommended.

Caution: Use of the VEXT command can produce unexpected results when operating in a non-Cartesian coordinate system. For a detailed description of the possible problems that may occur, see Solid Modeling in the ANSYS Modeling and Meshing Guide.

If the area that is being extruded (used as the pattern for the resulting volume) with the VROTAT, VEXT, VOFFST, or VDRAG command is meshed (or belongs to a meshed volume), that mesh will be used as a pattern for the mesh of the volume that is created (see Extruding Meshed Areas). (Compare these commands to the VSWEEP command, which is described in Sweeping Volumes.)

If you are interested in extruding your mesh, follow these steps:

Mesh the area that is to be extruded, dragged, offset, or rotated (using MESH200 elements).

Select an appropriate 3-D element type [ET] (match the shape and number of nodes to the MESH200 element). Activate the selection [TYPE].

Specify the desired number of element divisions in the extruded, rotated, or offset direction (NDIV argument on ESIZE command). If using VDRAG, specify the number of element divisions on the drag path line(s) (LESIZE or ESIZE,,NDIV).

Issue the VROTAT, VEXT, VOFFST, or VDRAG command.

Concatenated areas [ACCAT] or areas that have concatenated lines [LCCAT] cannot be extruded. You can get around the concatenated line limitation by first meshing the area(s), then deleting the concatenated lines, and finally extruding the area(s) into meshed volume(s).

If element attributes have been associated with the pattern area via the AATT command, the opposite area generated by the VDRAG, VEXT, VOFFST, or VROTAT operation will also have those attributes (i.e., the element attributes from the pattern area are copied to the opposite area). Note that only the area opposite the pattern area will have the same attributes as the pattern area; the areas adjacent to the pattern area will not.

Use the following command to make the generation of meshed volumes from 2-D models easier:  

Command(s):

Use the following command to make the generation of meshed volumes from 2-D models easier:  

Command(s):
EXTOPT

GUI:
Main Menu>reprocessor> Modeling> Operate> Extrude> Elem Ext Opts  
Main Menu> Preprocessor> Meshing> Mesh> Volume Sweep> Sweep Opts  

EXTOPT controls options relating to the generation of volume elements from area elements using the VEXT, VROTAT, VOFFST, VDRAG, and VSWEEP commands. It enables carry-over of material attributes, real constant attributes, and element coordinate system attributes of the pattern area elements to the created volume elements (except for VSWEEP as noted below).

The EXTOPT control options include the following:

When using VEXT, VROTAT, VOFFST, or VDRAG, you can set controls to carry-over material attributes, real constant attributes, and element coordinate attributes of the pattern area elements to the meshed volume elements. (When using VSWEEP, since the volume already exists, use the VATT command to assign attributes before sweeping.)

When using VEXT, VROTAT, VOFFST, or VDRAG, you can set controls to carry-over particular attributes (materials, real constants or element coordinate systems) of the pattern area elements to the generated volume elements or you can set controls to use particular attributes (material, real constants or element coordinate systems) of the current MAT, REAL, and ESYS command settings for the generated volume elements.

You can set controls to set the number of element divisions and spacing ratio in the direction of volume generation.

When using VEXT, VROTAT, VOFFST, or VDRAG, you can set controls to clear the pattern area mesh when volume generations are done. (When you are using VSWEEP, if selected, the area meshes on the pattern (source), target, and/or side areas clear when volume sweeping is done.)

The carry-over of the attributes of the pattern area elements saves you time that would otherwise be required to prepare the 3-D model extrusion of multiple areas with differing attributes.

Figure 5.13. Extruding (and Scaling) Meshed Areas Into Meshed Volumes

5.2.5.3. Sweeping Volumes
To fill an existing unmeshed volume with elements by sweeping the mesh from an adjacent area throughout the volume:  

Command(s):
VSWEEP

GUI:
Main Menu> Preprocessor> Meshing> Mesh> Volume Sweep> Sweep

When you use the VROTAT, VEXT, VOFFST, and VDRAG commands to extrude a meshed area into a meshed volume, ANSYS creates the volume and the volume mesh simultaneously. In contrast, you use the VSWEEP command in an existing unmeshed volume. Thus VSWEEP is particularly useful when you are importing a solid model that was created in a CAD program.

For detailed information about volume sweeping, see Generating a Volume Mesh By Sweeping of this manual, as well as the description of the VSWEEP command in the ANSYS Commands Reference.
seansheu

端面

雨人
实体见附图

  单元图为：

mars_88
看看能不能得分。我的螺旋线是分段做的，不知有没有一次做好的方法？端面单元为shell93，实体的是solid95。

aser

图1

雨人
/PREP7
wpoff,-10
CYL4, , ,1  
ET,1,MESH200
ET,2,SOLID45
KEYOPT,1,1,6
KEYOPT,1,2,0
LESIZE,ALL,,,10,,,,,1  
MSHAPE,0,2D  
MSHKEY,1
AMESH,ALL

CSYS,0   
WPAVE,0,0,0  
CSYS,0   
!*   
CSYS,1      

KBETW,3,1,0,RATI,0.5,   
*do,i,1,72
k,5+i,10,180-i*10,i
lstr,5+i,4+i
*enddo
*do,i,1,72
VDRAG,1+(i-1)*5, , , , , ,4+i
eplot
*enddo

zxl
CSYS,1   
*AFUN,DEG
/prep7
ET,1,45
*do,i,0,36,1
  x=10
  y=10*i
  z=i/2
k,i+1,x,y,z
*enddo

*do,j,1,36,1
L,j,j+1
*enddo

*do,i,0,35,1
LWPL,-1,i+1,0
CYL4,0,0,1
*enddo

*do,i,1,36,1
VDRAG, i, , , , , , i, , , , ,
*enddo

vglue,all
TYPE,1
vmesh,all

spring_zj
回复： 【推荐】积分鼓励，做弹簧划分网格

我在SOLIDWORKS 下面建立弹簧模型，再转到ANSYS下面SWEP单元，采用SOLID95单元。看看如何？

cshufen
所谓三变弹簧是变刚丝直径，变螺距，变圈径的变刚度弹簧，这种弹簧在国外的越野汽车上很是时毛，有兴趣的可以做一下。
有水平的作个三变弹簧
77152587
首先绘出中心线 x=cosωt,y=sinωt,z=vt，其中ω控制旋转速度，v控制螺旋上升速度（即可以控制旋转一圈螺旋弹簧上升的高度），以及横截面；
然后面沿线操作即可得到螺旋弹簧，当然只需要画一周，再复制。
这样是可以的，t为时间变量，由于正弦、余弦函数为以2π为周期的周期函数，所以只需要画一个周期即可，然后复制就得到等距的螺旋弹簧。如果想得到变距离的螺旋弹簧，只需要将速度变量设置为变速的。

superalloy

看看这个。三变弹簧。

lovelybunny

 我编的。MAC文件，用法将此文件拷贝到ANSYS的工作目录下，然后在命令窗口打ring1命令即可，运行后会弹出对话框，设置参数后，自动进行建模，此程序实行参数化建模。。通过修改对话框中的参数即可获得不同的已经划分网格的FEA模型。
fini
/cle
/filname,ring,1
/prep7
*AFUN,DEG
multipro,'start',3
*cset,1,3,N_num,'Enter the loop nmuber',5
*cset,4,6,p_dis,'Enter the pitch',0.8
*cset,7,9,rid,'Enter the spring main radius',1
*cset,10,12,rid2,'Enter the spring section radius',0.1
*cset,61,62,'The ring1 macro creat',' the sping you wanted'
multipro,'end'
TOT=12
N=TOT*N_num !整个弹簧的点数
cic=360
et,1,45 !弹簧采用的单元
et,2,200 !给面划网格的MESH200单元
keyopt,2,1,6

DIV=cic/TOT !两点将的圆心角
DISp_dis/TOT !螺距
csys,1

*DO,I,1,N+1
k,I,rid,(I-1)*DIV,(I-1)*DIS
*ENDDO

flst,3,N+1,3
*do,i,1,N+1
fitem,3,i
*enddo
bsplin,,p51x

csys,0
wprot,,90
wpoff,rid
pcirc,rid2,,0,360

asel,all
lsla,s
lesi,all,,,4
type,2
mshkey,0
amesh,all
eplot

type,1
extopt,esize,300
vdrag,1,,1
eplot
这是默认的参数设置后，的FEA网格
77152587
当速度vel随时间变化时所得到的变间距曲线的弹簧；当旋转角速度随时间变化时所得到的半径放大或缩小的曲线的弹簧。

fini
/cle
/prep7

vel=1
wnat=10
pi=3.14
start_time=0
end_time=6*pi/wnat
step_time=2*pi/wnat/20

n_iter=(end_time-start_time)/step_time+1

*do,iter,1,n_iter
   x=sinwnat*(iter-1)*step_time)
   y=cos(wnat*(iter-1)*step_time)
   z=vel*(iter-1)*step_time
   n,iter,x,y,z
*enddo

et,1,4
r,1,10

*do,iter,1,n_iter-1
   e,iter,iter+1
*enddo
wwebhua
附件中的图  是不是也可以通过您的这种方式生成阿？  谢谢

David2003
一个比较简单的螺旋弹簧，请指教。
采用了solid45单元，建模后用lesize命令控制一下线上单元尺寸，然后进行sweep网格划分。以下是采用了柱坐标进行建模的命令：
/prep7
*afun,deg
CSYS,1
radl=0.45
rads=0.05
dist=0.15
k,1,radl,0,0
k,2,radl,120,dist
k,3,radl,240,2*dist
k,4,radl,0,3*dist
k,5,radl,120,4*dist
k,6,radl,240,5*dist
k,7,radl,0,6*dist
l,1,2
l,2,3
l,3,4
l,4,5
l,5,6
l,6,7
LCOMB,1,2,0
LCOMB,1,3,0
LCOMB,1,4,0
LCOMB,1,5,0
LCOMB,1,6,0
csys,0
wpro,,-90,
cyl4,radl,0,rads
vdrag,1,,,,,,1
WPSTYLE,,,,,,,,0