Blocks Set with Discontinuous Boundaryexamples|products|Murata Software Co., Ltd.

Example22 Blocks Set with Discontinuous Boundary

General

  • The “discontinuous” boundary condition is studied in this exercise. The model consists of two blocks contacting each other.
     

  • The contacting bodies are considered to be one by default, as far as the mechanical connectivity is concerned.
    By setting the discontinuous boundary condition on the contacting face, the default is lifted and the contacting face becomes separated.
     

  • The deformation, the displacement and the mechanical stress are solved.
     

  • Unless specified in the list below, the default conditions will be applied.
     

 

Analysis Space

Item

Settings

Analysis Space

3D

Model unit

mm

 

Analysis Conditions

Item

Settings

Solvers

Mechanical Stress Analysis [Galileo]

Analysis Type

Static analysis

Options

N/A

Model

The two bodies are made of polyethylene.

The bottom faces of the bodies are fixed and one body is pulled outward. The pulling force is applied on an edge of the body.

The discontinuous boundary condition is set on the contacting face of the two bodies.

 

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

0/Solid

BLOCK

000_Polyethylene(PE) *

1/Solid

BLOCK

000_Polyethylene(PE) *

 

* Available from the Material DB

Boundary Conditions

Boundary Condition Name/Topology

Tab

Boundary Condition Type

Settings

FIX/Face

Mechanical

Displacement

UX=0, UY=0, UZ=0

NONCONT/Face

Symmetry/Continuity

Discontinuous

Select “Discontinuous”

PULL/Edge

Mechanical

Distributed edge load

X=1,Y=Z=0 [N/m]

 

Results

The displacement diagram is shown below. The contour diagram shows the displacement.

The face on which the discontinuous boundary condition is set is treated as two independent faces. Therefore the two bodies are separated by a gap.

 

If the continuous boundary condition is set on it, the two bodies remain in contact as shown below.

 

NOTE

In this exercise, one of the bodies is pulled outward and it bends away from the other.

If the force is applied inward, it will bend towards the other, and get into it as if it does not exist, which is the wrong result. In such a case, simple contact should be used as the boundary condition on the shared face.

The simple contact boundary condition can be used wherever the discontinuous boundary condition is applicable. Please note, however, that the calculation time of the simple boundary condition is longer than that of the discontinuous boundary condition.