Hydrostatic pressureexamples|products|Murata Software Co., Ltd.

Example57 Hydrostatic pressure

General

  • Deformation by the hydrostatic pressure is simulated.
     

  • 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

As the buoyant force causes acceleration in +Z direction, setting on the High-level setting tab is done as follows.

Tab

Setting Item

Setting

High-level setting

Setting of mechanical stress analysis and piezoelectric analysis

Perform static analysis in the acceleration environment with inertial force being taken into account.
is selected

 

Graphical Objects

A model is like a submarine going down to the sea bottom.

Body Attributes and Materials

Body Number/Type

Body Attribute Name

Material Name

0/Solid

submarine

007_Fe *

* Available from the Material DB

Boundary Conditions

The hydrostatic pressure on the whole surface of the model is proportional to the depth. The pressure P is obtained in the expression below.

 

Pgh

 

where ρ is density [kg/m3], g is gravitational acceleration[m/s2], and h is depth[m]. In the case of water,

 

P=9800h[Pa]

 

 

  • In this model, the boundary condition is only pressure. The displacement is not constrained.

Generally, the simulation cannot be performed without constraining the displacement. Femtet is, however, capable of doing so without constrained displacement.

 

 

For the Pressure, set “Distribution Data” of the “Edit Boundary Condition”.

 

 

In the [Edit Distribution Data] dialog box, select 1D and Z direction in the Local Coordinates. In the [Coordinates-Pressure] Table,

specify the pressures at two points in the area where the whole body is included. Linear interpolation is applied between the points.

 

 

 

After meshing, select “Distributed pressure” in the Mesh display to show the pressure distribution of the surface.

 

Results

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

 

The whole body shrinks under the pressure. The deformation is irregular due to its asymmetric shapes of upper and bottom sides of the model.

If the model is symmetric, the shrinkage will be observed uniformly over the whole body.