ANSYS中plane183单元

PLANE183

2-D 8-Node or 6-Node Structural Solid

MP ME ST PR PRN DS <> <> PP EME MFS

Product Restrictions

PLANE183 Element Description

PLANE183 is a higher order 2-D, 8-node or 6-node element. PLANE183 has

quadratic displacement behavior and is well suited to modeling irregular

meshes (such as those produced by various CAD/CAM systems).

This element is defined by 8 nodes or 6 nodes having two degrees of freedom

at each node: translations in the nodal x and y directions. The element may be

used as a plane element (plane stress, plane strain and generalized plane strain)

or as an axisymmetric element. This element has plasticity, hyperelasticity,

creep, stress stiffening, large deflection, and large strain capabilities. It also has

mixed formulation capability for simulating deformations of nearly

incompressible elastoplastic materials, and fully incompressible hyperelastic

materials. Initial state is supported. Various printout options are also available.

See

PLANE183

in the

Mechanical APDL Theory Reference

for more details

about this element.

Figure 183.1: PLANE183 Geometry

PLANE183 Input Data

The geometry, node locations, and the coordinate system for this element are

shown in

Figure 183.1: PLANE183 Geometry

.

Although a degenerated triangular-shaped element may be formed by defining

the same node number for nodes K, L and O when KEYOPT(1) = 1, it is better

to use KEYOPT(1) = 1 for triangular shaped elements. In addition to the nodes,

the element input data includes a thickness (TK) (for the plane stress option

only) and the orthotropic material properties. Orthotropic material directions

correspond to the element coordinate directions. The element coordinate

system orientation is described in

Coordinate Systems

.

Element loads are described in

Nodal Loading

. Pressures may be input as

surface loads on the element faces as shown by the circled numbers

in

Figure 183.1: PLANE183 Geometry

. Positive pressures act into the element.

Temperatures may be input as element body loads at the nodes. The node I

temperature T(I) defaults to TUNIF. If all other temperatures are unspecified,

they default to T(I). If all corner node temperatures are specified, each midside

node temperature defaults to the average temperature of its adjacent corner

nodes. For any other input temperature pattern, unspecified temperatures

default to TUNIF.

The nodal forces, if any, should be input per unit of depth for a plane analysis

(except for KEYOPT(3) = 3 or KEYOPT(3) = 5) and on a full 360° basis for an

axisymmetric analysis.

As described in

Coordinate Systems

, you can use

ESYS

to orient the material

properties and strain/stress output. Use

ESYS

to choose output that follows

the material coordinate system or the global coordinate system. For the case of

hyperelastic materials, the output of stress and strain is always with respect to

the global Cartesian coordinate system rather than following the

material/element coordinate system.

KEYOPT(3) = 5 is used to enable generalized plane strain. For more

information about the generalized plane strain option, see

Generalized Plane

Strain

in the

Element Reference

.

KEYOPT(6) = 1 sets the element for using mixed formulation. For details on the

use of mixed formulation, see

Applications of Mixed u-P Formulations

in

the

Element Reference

.

You can apply an initial stress state to this element via

the

INISTATE

command. For more information, see

Initial State

in the

Basic

Analysis Guide

.

The effects of pressure load stiffness are automatically included for this

element. If an unsymmetric matrix is needed for pressure load stiffness effects,

use

NROPT

,UNSYM.

The next table summarizes the element input.

Element Input

gives a general

description of element input. For axisymmetric applications see

Harmonic

Axisymmetric Elements

.

PLANE183 Input Summary

Nodes

I, J, K, L, M, N, O, P when KEYOPT(1) = 0

I, J, K, L, M, N when KEYOPT(1) = 1)

Degrees of Freedom

UX, UY

Real Constants

None, if KEYOPT (3) = 0, 1, or 2

THK - Thickness if KEYOPT (3) = 3

Material Properties

TB

command: See

Element Support for Material Models

for this

element.

MP

command: EX, EY, EZ, PRXY, PRYZ, PRXZ (or NUXY, NUYZ, NUXZ),

ALPX, ALPY, ALPZ (or CTEX, CTEY, CTEZ

or

THSX, THSY, THSZ),

DENS, GXY, GYZ, GXZ, ALPD, BETD

Surface Loads

Pressures --

face 1 (J-I), face 2 (K-J), face 3 (L-K), face 4 (I-L) when KEYOPT(1) = 0

face 1 (J-I), face 2 (K-J), face 3 (I-K) when KEYOPT(1) = 1

Body Loads

Temperatures --

T(I), T(J), T(K), T(L), T(M), T(N), T(O), T(P) when KEYOPT(1) = 0

T(I), T(J), T(K), T(L), T(M), T(N) when KEYOPT(1) = 1

Body force densities --

The element values in the global X and Y directions.

Special Features

Birth and death

Element technology autoselect

Initial state

Large deflection

Large strain

Linear perturbation

Material force evaluation

Nonlinear stabilization

Rezoning

KEYOPT(1)

Stress stiffening

Element shape:

0 --

8-node quadrilateral

1 --

6-node triangle

KEYOPT(3)

Element behavior:

0 --

Plane stress

1 --

Axisymmetric

2 --

Plane strain (Z strain = 0.0)

3 --

Plane stress with thickness (TK) real constant input

5 --

Generalized plane strain

KEYOPT(6)

Element formulation:

0 --

Use pure displacement formulation (default)

1 --

Use mixed u-P formulation (not valid with plane stress)

PLANE183 Output Data

The solution output associated with the element is in two forms:

?

?

Nodal displacements included in the overall nodal solution

Additional element output as shown

in

Table 183.1: PLANE183 Element Output Definitions

.

Several items are illustrated in

Figure 183.2: PLANE183 Stress Output

.

The element stress directions are parallel to the element coordinate system. A

general description of solution output is given in

Solution Output

. See the

Basic

Analysis Guide

for ways to view results.