onsas / onsas

An Open Nonlinear Structural Analysis Solver for GNU-Octave or Matlab

ONSAS: an Open Nonlinear Structural Analysis Solver for GNU-Octave/Matlab

About ONSAS

ONSAS is a GNU-Octave/Matlab code for static/dynamic and linear/non-linear analysis of structures. The first version was developed for educational purposes and was published in a handbook of the course Análisis no lineal de Estructuras taught at Facultad de Ingeniería, Universidad de la República since 2017.

Some examples

A deployable ring

A propeller model

A truss tower model

Contact

You can send an e-mail to jorgepz [AT] fing.edu.uy .

License

The code is distributed under a GNU-GPL 3.0 license.

How to use ONSAS

The user should follow these steps to install and run onsas:

1. Download and install GNU-Octave and Paraview
2. Download the ONSAS zip source files from the realeases web https://github.com/ONSAS/ONSAS/releases
3. Open GNU-Octave, move to the examples directory and run one of the examples.

An introduction to using and contributing to ONSAS was presented in 2022. The recording is available at this youtube video.

Contributions

The complete list of authors of code, contributions, affiliations and acknowledgments is available in the documentation.

onsas's Issues

change crossSecsParams type

change crossSecsParams to cell type (like materialsParams).

show header in long table of increments

change to esmac format dxf

implement exp finite rotations update rule for frame co-rotational

• correct errors when using exponential update
• validate using some example

normal forces values in deformed structure

No "analysis time" shown

Test with input file: onsas_input_TEST_cantileverNodalMoment.m

include linear truss elements

Suspicious analysisNM

line 70, output argument KL0

GUI version verification

Add a verification of the octave version >5.1.0.

changes in simple rope example

Changes to do in simpleRope example:

• add length to the initial reference configuration of the rope
• use camelCase in the filename and delete comments in the script
• reduce timeStep

include figures in report

Incluir tReadingInpiut en InputsVarsVerfication

SI no esta definido tira error.

error in normal force of pre-stressed truss elements

Correct sizes of GUI elements in hdpi screens

Correct button and text sizes of GUI in hdpi screens

automate the computation of section properties for truss/beams

change to esmac format gmsh

Plot normal force beams

The plot of normal force in beam elements in Octave has to be modified. All elements should be plotted and colormap should be applied.

change time shown in report for static loading.

deform structure in normal force Octave plot

deform structure in the normal force Octave plots.

error in angles in vtk beam2solids

improve information shown in iterations

include max strain in report

update report output

update material parameters table in report considering all constitutive models.

include prescribedDisps in nonlinear analyses

plotView parameters not updated when .m input file is loaded

add self-weight case

• truss elements
• tetrahedron elements
• beam elements

[ Errors in some structures with Releases ]

Differences with the analytical solution. The problem may be in the assembly of the matrix and the dree of freedoms.

File name: R2_pr3_ej3.m

bug vtk output

Bug 2 materials

solid tetraedron element in nonlinear analysis

include solid tetraedron element in nonlinear analysis

verification in inertial beam function

verify if it should be skew( Irhoe(x) * wdoter ) instead of Irhoe(x) * skew(wdoter) in this file:
https://github.com/grupomises/onsas/blob/f6b9a047eaa6e09f284922c8d513de904631e177/sources/elementBeamMassForce.m#L245

add lines support in msh4reader

update tower onsas example using dxf file

Execution time tables

Change times to exponential notation and add percentage in other column.

allow the assignment of more than one load case to the same element.

extract stresses from time-step iteration

Bug in example plateBeamColumn

Error in execution of plateBeamColumn

error: linearAnalysis: =: nonconformant arguments (op1 is 324x12x1, op2 is 3x1)
error: called from
linearAnalysis at line 574 column 37
ONSAS at line 52 column 3
runTestProblems at line 9 column 5

add neo-hookean solid

• implementation with complex step
• implementation with analytic expression of constitutive tensor

update control node/point input/output

test compatibility with MATLAB

test ONSAS in MATLAB and detect possible errors.

implement HHT method

correct and validate LBA analysis for cantilever

HHT parameter defintions

In Timestepdefinitions.m there is a mistake in the definition of hht parameters. The square is applied to alpha, should be applied to the whole parenthesis

incorrect number of columns in iterations table

incorrect number of columns in latex output table used in report. See/run example VonMisesNRAL example file.

Validate LBA for global buckling

Update consMatFlag in examples

This is a reminder that in PR #128 we updated the use of flag consMatFlag,

ONSAS/sources/elementTetraSolid.m

Line 84 in b5c2821

if elemConstitutiveParams(1) == 2 % Saint-Venant-Kirchhoff compressible solid

but some examples still need to be updated wrt that flag.

include inertial forces computation for beam elements

include the quadHexa vtk element

include the quadHexa vtk element in the vtkbeam2Solid function.

Save reactions history

update progress info

test possible vertical progress bar with estimated analysis ending time.