错误提示及解决方法

Diagnostics

: Error Messages

Error Messages

This section summarizes the most common error messages and solver messages generated

by COMSOL Multiphysics. All error messages are numbered and sorted in different categories

according to the following table.

TABLE 2-1: ERROR MESSAGE CATEGORIES

NUMBERS

CATEGORY

1000

–

1999 Importing Models

2000

–

2999

Geometry Modeling

3000

–

3999

CAD Import

4000

–

4999

Mesh Generation

5000

–

5999

Point, Edge, Boundary, and Subdomain

Specification

6000

–

6999

Assembly and Extended Mesh

7000

–

7999

Solvers

8000

–

8999

Postprocessing

9000

–

9999

General

For error messages that do not appear in the following lists, contact COMSOL’s support team

for help.

2000

–

2999 Geometry Modeling

TABLE 2-2: GEOMETRY MODELING ERROR MESSAGES

ERROR

NUMBER

ERROR MESSAGE

EXPLANATION

2118

Negative output from

empty input

Incorrect Geometry M-file.

2119

Non scalar output from

empty input

Incorrect Geometry M-file.

2120

Normal directions are

inconsistent

Incorrect input data from STL/VRML import.

2138

Self intersections not

supported

Curves resulting in self-intersections are not

supported.

2140

Singular extrusions not

supported

Error in input parameters.

2141

Singular revolutions not

The revolved mesh has a singularity at the z axis. If

supported

possible, create the cylinder using a 3D primitive or

by revolving the geometry before meshing.

2146

Subdomain must

bounded at least four

boundary segments

Incorrect geometry for mapped mesh.

2147

Subdomain must bound

Incorrect geometry for mapped mesh.

one connected edge

component only

2190

Invalid radius or distance

Incorrect input parameters to fillet/chamfer.

2197

Operation resulted in

empty geometry object

Geometry operation resulted in an empty geometry

object which is not allowed. Make sure an empty

geometry object is not created.

2209

Geometry to revolve may

The axis of revolution and the geometry intersect.

not cross axis of

Check the dimension of the geometry and the

revolution

definition of the axis for the revolution.

4000

–

4999 Mesh Generation

TABLE 2-3: MESH GENERATION ERROR MESSAGES

ERROR

NUMBER

ERROR MESSAGE

EXPLANATION

4002

A degenerated

tetrahedron was

created

The mesh generator ran into numerical difficulties while

creating tetrahedrons with a size based on user-controlled

parameters. Causes could be too small and narrow

subdomains relative to the rest of the geometry or

exceedingly short boundary segments. Try to avoid

creating small and narrow subdomains and very short

boundary segments that are adjacent to longer boundary

segments.

4003

A degenerated

triangle was

created

The mesh generator ran into numerical difficulties while

creating triangles with a size based on user-controlled

parameters. Causes could be too small and narrow

subdomains relative to the rest of the geometry or

exceedingly short boundary segments. Try to avoid

creating small and narrow subdomains and very short

boundary segments that are adjacent to longer boundary

segments.

4012

Cannot create

The geometry does not fulfill the topological requirements

mapped mesh for

for a mapped mesh. Changes in input parameters or further

this geometry

subdomain division can possibly help this.

4026

Failed create

matching edge

discretizations

Cannot make mapped mesh with the given input

parameters.

4029

Failed to insert

point

Problems inserting point at given coordinate. Manually

inserting a point there may help.

4031

Failed to respect

The mesh generator failed in making the elements

boundary element

compatible with the geometry object’s edges. The reason

on geometry edge

for this could be that the face mesh is too coarse or

contains adjacent elements with large differences in scale.

Another reason can be that some subdomains in the

geometry are too narrow with respect to the rest of the

geometry.

4032

Failed to respect

See Error message 4031.

boundary element

on geometry face

4044

Internal error

boundary

respecting

See Error message 4031.

4054

Invalid topology of

The geometry object cannot be used for creating a mapped

geometry

mesh. It must be subdivided.

4055

Isolated entities

found

Entities that are not connected to the boundaries of a

geometry objects is found. The mapped mesh generator

does not support such isolated entities.

4119

Singular edge

detected

The geometry object contains an edge of zero length.

6000

–

6999 Assembly and Extended Mesh

TABLE 2-4: ASSEMBLY AND EXTENDED MESH ERROR MESSAGES

ERROR

NUMBER

ERROR MESSAGE

EXPLANATION

6008

Circular

variable

dependency

detected

A variable has been defined in terms of itself, possibly in a

circular chain of expression variables. Make sure that variable

definitions are sound. Be cautious with equation variables in

equations.

6063

Invalid degree

of freedom

name

The software does not recognize the name of a degree of

freedom. Check the names of dependent variables that you

have entered for the model. See also Error 7192.

6139

Wrong number

The current solution or the stored solution has for some

of DOFs in

reason the wrong number of degrees of freedom, sometimes

initial value

due to a change of the implementation of elements between

two versions of the software. To overcome the problem, go to

the

Initial value

area in the

Solver Manager

, and select

Initial value expression

. Then the initial value expressions

is evaluated without using the current or stored solution.

6140

Wrong number

of dofs in

linearization

point

The current solution or the stored solution has for some

reason the wrong number of degrees of freedom, sometimes

due to a change of the implementation of elements between

two versions of the software. To overcome the problem, go to

the

Value of variables not solved for and linearization

point

area in the

Solver Manager

, and click the

Use

setting from Initial value frame

button or the

Zero

button.

6163

Divide by zero

A property in the model contains a divisor that becomes zero.

Check to make sure that division by zero does not occur in

any expression or coefficient.

6164

Duplicate

variable name

A variable name has two different definitions. For instance,

the same variable name appears two or more times for a

dependent variable, a constant, an expression variable, or a

coupling variable. Remove or rename one of the variables.

6170

Failed to

evaluate

variable

An error occurred when evaluating the variable. The domains

in which COMSOL Multiphysics tried to evaluate the

variable are indicated. Also, the error message shows the

expression that COMSOL Multiphysics was unable to

evaluate. Make sure that you have defined the variables

correctly in the indicated domains.

6176

An expression contains

log(a)

, where

a

becomes negative

Attempt to

evaluate real

or zero. To make the logarithm well- defined, make sure that

a>0

. Often,

a

becomes only slightly negative (due to

logarithm of

negative number

approximations in the solution process). Then, a possible

solution is to use

log(a+e)

, where

e

is a small constant.

Another remedy is to use

log(abs(a))

. If you do want to

have a complex logarithm, go to the

Advanced

tab of

Solver

Parameters

and select the

Use complex functions with

real input

check box.

6177

Matrix has zero

When the equations have a structure such that the stiffness

on diagonal

matrix (Jacobian matrix) has zeros on the diagonal, it is not

possible to use the following linear system

solvers/preconditioners/smoothers: all versions of SOR and

Diagonal scaling (Jacobi). Try the Vanka

preconditioner/smoother instead.

6188

Out of memory

The software ran out of memory during assembly of the finite

during assembly

element model. See error 7144 regarding general

memory-saving tips.

6194

An expression contains

a^b

, where

a

becomes negative and

Attempt to

b

is not an integer. To make the power well-defined, make

evaluate

sure that

a>0

. Often,

a

becomes only slightly negative (due

non-integral

power of

to approximations in the solution process). Then, a possible

negative number

solution is to use

(a+e)^b

, where

e

is a small constant.

Another remedy is to use

abs(a)^b

. If you do want to have

a complex number

a^b

, go to the

Advanced

tab of

Solver

Parameters

and select

Use complex functions with real

input

.

6199

The model contains a

sqrt

(square root) function that takes

Attempt to

evaluate real

the square root of a negative number. Either make sure that

square root of

the square- root argument is nonnegative or select the

Use

negative number

complex functions with real input

check box on the

Advanced

tab in the

Solver Parameters

dialog box.

6204

Undefined

function call

An expression contains an undefined function name. Check

that the function name is correct and that the function is in

COMSOL Multiphysics’ or MATLAB’s path.

6206

Internal

Not-A-Number (NaN) appears unexpectedly. A possible

evaluation error:

cause is improperly defined coupling variables. As a first step,

unexpected NaN

check that the definitions of the source and destination

encountered

domains of any coupling variables or periodic boundary

conditions are correct.

6245

Unsupported

Integration order is too high. For triangular elements the order

integration order

can be up to 10, and for tetrahedral elements the order can be

up to 8. Find more information in the section

“Numerical

Quadrature” on page 505

.

6259

Failed to

evaluate

variable

Jacobian

An error occurred when evaluating the Jacobian of the

indicated variable. The domains in which COMSOL

Multiphysics tried to evaluate the variable are indicated.

Make sure that you have defined the variable correctly in the

indicated domains.

7000

—

7999 Solvers and Preconditioners

TABLE 2-5: SOLVER ERROR MESSAGES

ERROR

NUMBER

ERROR MESSAGE

EXPLANATION

7001

Adaption only

implemented for

It is only possible to use adaptive mesh refinement in

3D for models using tetrahedral mesh elements.

tetrahedral meshes

Either turn off adaptive mesh refinement or switch

from brick or prism elements to tetrahedral elements.

7002

Adaption only

implemented for

triangular meshes

It is only possible to use adaptive mesh refinement in

2D for models using triangular mesh elements. Either

turn off adaptive mesh refinement or switch from

quadrilateral elements to triangular elements.

7022

Segregated solver steps

The groups for the segregated solver do not include

do not involve all of

all dependent variables. One reason for this error

solcomp

could be that some boundary conditions (for example,

for laminar inflow in fluid-flow models) add

dependent variables that are not initially in the model.

7043

Initial guess leads to

This error message usually appears when you have

undefined function value

set up an expression that returns “not a value,” that is,

it is undefined, for the initial condition you have set.

For instance, this happens if an expression contains a

divisor that becomes zero or a logarithm of a negative

value. To solve the problem, change the expression or

the initial value so that the expression is well-defined

when substituting the initial value of the variables.

Also, watch out for warnings in the Log window.

7067

System matrix is zero

This error message appears if there are no volume

elements in the mesh. In the case that you have a

mapped surface mesh, try sweeping or extruding the

surface mesh to get a volume mesh.

7069

Maximum number of

The iterative linear system solver did not converge

linear iterations reached

due to a bad initial guess or a bad preconditioner.

Increase the limit on the number of linear iterations

or use a better preconditioner. If possible, use a direct

linear system solver.

7081

No parameter name

given

The parametric solver does not find a name for the

parameter. Check the

Name of parameter

edit field

on the

General

page of the S

olver Manager

.