FEM ConstraintSelfWeight

Other languages:

Constraint centrif

Constraint initial temperature

FEM

Menu location
FEM ConstraintSelfWeight
Model → Mechanical boundary conditions and loads → Gravity load
Workbenches
FEM
Default shortcut
None
Introduced in version
-
See also
FEM tutorial
Contents 1 Description 2 Usage 3 Scripting 4 Solver CalculiX 4.1 Limitations 4.2 Editing CalculiX input file 5 Solver Z88

Solvers
CalculiX, Elmer

Description

Defines a gravity acceleration acting on the whole model in the prescribed direction.

^{0.21 and below}: The acceleration has a fixed value of 9.81 m/s^2.

Usage

There are several ways to invoke the command:
- Press the Gravity load button.
- Select the Model → Mechanical boundary conditions and loads → Gravity load option from the menu.
A ConstraintSelfWeight object is created.
introduced in 1.0: Optionally change its DataGravity Acceleration property.
Optionally change its DataGravity Direction property.

Scripting

New object:

import ObjectsFem
ObjectsFem.makeConstraintSelfWeight(name)

Add object to the analysis named Analysis:

App.ActiveDocument.Analysis.Member = App.ActiveDocument.Analysis.Member + [(object)]

Example:

import ObjectsFem
selfweight_obj = ObjectsFem.makeConstraintSelfWeight("MySelfWeightObject")
App.ActiveDocument.Analysis.Member = App.ActiveDocument.Analysis.Member + [selfweight_obj]

Solver CalculiX

Limitations

^{0.21 and below}: You need to modify the .inp file to edit gravity acceleration.
Self-weight is applied to the element set Eall which includes the whole model.

Editing CalculiX input file

The acceleration constant can be manually edited after generating the CalculiX input file.

Example of lines in the .inp file:

*DLOAD
Eall,GRAV,9810,0.0,0.0,-1.0

where 9810 is a gravity acceleration magnitude in [mm/s^2], and 0,0,-1 is the direction vector. The value can be set as a multiple of standard gravity acceleration to simulate loading of e.g. 4g.