在ANSYS中如何对节点进行耦合Coupling操作？
一、ANSYS中同一节点同一方向不能在2个耦合集中出现
2D螺旋桩土模型，下图绿色圆圈内的节点属于水平线与竖向线的交点，在之前的操作中，分别对水平线和竖向线施加了节点耦合命令（CPINTF,ALL），在求解时程序提示绿色圆圈内的节点在同一方向（如UX)属于2个耦合集，导致计算不能继续进行。
1、ANSYS HELP 文件位置
2、
What
Is Coupling?
When you need to force two or more degrees of
freedom (DOFs) to take on the same (but unknown) value, you
can couple these
DOFs together. A set of coupled DOFs contains
a prime DOF,
and one or more other DOFs. Coupling will cause only the prime DOF
to be retained in your analysis' matrix equations, and will cause
all the other DOFs in a coupled set to be
eliminated. The value calculated for the prime DOF will then
be assigned to all the other DOFs in a
coupled set.
Typical applications for coupled DOFs
include: 1) maintaining symmetry on partial models, 2) forming pin,
hinge, universal, and slider joints between two coincident nodes,
and 3) forcing portions of your model to
behave as rigid bodies (see this chapter's discussion of
constraint equations for more general rigid region capability).
三、
对节点进行耦合的操作方法
1、 How
to Create Coupled Degree of Freedom Sets
You can use several different methods to create a coupled
degree-of-freedom set. These include the CP command
and other commands such as CPNGEN, CPINTF,CPLGEN,
and CPSGEN.
These methods of generating coupled sets are discussed in the
following sections.
In addition to the methods discussed
here, you can use the internal multipoint
constraint (MPC) feature of certain contact elements
(CONTA171, CONTA172,CONTA173, CONTA174, CONTA175, CONTA176,
and CONTA177)
to model coupling constraints. By this method, the program builds
MPC equations internally based on the contact kinematics.
See Multipoint
Constraints and Assemblies in the Contact
Technology Guide for more information on
how to use this feature.
After creating a coupled set of nodes, you can include more nodes
in that set by simply performing an
additional coupling operation (be sure to use the same set
reference number). You can also use selecting logic to couple "ALL"
of the selected nodes. Nodes can be deleted from a coupled set by inputting them
as negativenode
numbers on the CP command.
To modify a coupled DOF set (that is, add or
delete nodes, or change the DOF label), use
the CPNGEN command.
(You cannot access the CPNGEN command
directly in the GUI.)
The CPINTF command
couples coincident nodes in a model by
generating one coupled set for each specified DOF label at every
pair of coincident nodes. This operation is useful 3"buttoning"
together several pairs of nodes (such as at a
seam).
Instead of coupling coincident nodes, you can use one of these
alternative methods to force the nodes to behave in the same
way:
-
If all DOFs
are to be coupled for coincident nodes, it is usually more
efficient to simply merge those nodes together by using
the NUMMRG command
(Main Menu>
Preprocessor> Numbering Ctrls> Merge
Items).
-
You can connect coincident pairs of
nodes by creating 2-node elements between them by using
the EINTF command
(Main Menu>
Preprocessor> Modeling> Create> Elements> Auto
Numbered> At Coincid Nd).
-
To tie together two regions having
dissimilar mesh patterns, use
the CEINTF command
(Main Menu>
Preprocessor> Coupling/Ceqn> Adjacent
Regions). This operation generates constraint
equations that connect the selected nodes of one region to the
selected elements of the other region
三、解决方法
1、 使用CPINTF命令
以上图为例，在完成水平线节点的耦合操作后，选择竖向线上的节点，并剔除公用节点，在使用CPINTF,ALL命令即可。
3、multipoint
constraint (MPC) approach
You can use the internal multipoint constraint
(MPC) approach (KEYOPT(2) = 2), in
conjunction with certain bonded and no separation contact
definitions (KEYOPT(12) = 4, 5, or 6), to define various contact
assemblies and kinematic constraints. This capability is available
for contact elements CONTA171, CONTA172,CONTA173, CONTA174, CONTA175, CONTA176,
and CONTA177.
By this method, the program builds MPC equations internally based
on the contact kinematics. You can use this method to model the
following contact assemblies and surface-based
constraints:
加载中，请稍候......
加载中…
(2015-10-09 08:53:02)