# software

## Need user material Fortran code for viscoelastic

Where I can find the subroutine of a user material Fortran code for Viscoelastic constitutive model?

Does anyone has the subroutine for LS-DYNA ?

Can anyone help me?

## stepTime VS. totalTime

Hello everyone,

I have a problem with one user subroutine.

The fact is that, debugging the subroutine I see the totaltime different from the steptime. I am using just one step and the .inp implementation is veryfied with a different user subroutine, so totaltime and steptime should be exactly the same (but they are not...)

The value of the total time is around 1e-8 and the value of the steptime is around 1e-55.

Could anyone give me a clue?

## Question on Abaqus Mohr-Coulomb hardening definition

Hi Expert,

I'm a newer of Abaqus. I was trying to compute a simple compression problem using Mohr-Coulomb model. I found the slope of stress-strain curve from the results is double of that defined in the input file. I don't know what's cause it or my understand of the slope is wrong.

Only one 8 node C3D8 element is involved. To simplify the question, let the friction angle be 0, it reduces to a Tresca model actually. The material is defined as:

*ELASTIC, TYPE=ISOTROPIC
3.350000E+07, 2.000000E-01,
*MOHR COULOMB
0.,0.
*MOHR COULOMB HARDENING
10000.,0.
3360000.,1.

The hardening slope defined above is 3.35E+6.

## Question about specific boundary condition in Fluent

Dear Friends

Does anybody know how can I add following boundary condition in Fluent software for outlet of an internal flow ? Is there any easy way without needing UDF or etc.

Where p is pressure, Re is Reynolds number and vn is the velocoty component normal to the outlet section.

PLZ.......

## Modal Analysis in Ansys to get natural frequencies and compare them with theory results

Hi, I'm Pietro, a short term Italian incoming student at VT (virginia tech).

My advisor, in order to start my thesis there about skin friction coefficients in a scramjet combustion chamber, gave me a Modal analysis to do on a gage described as follow:

a cantilever beam  (1mm diameter and 3cm long cylindrical shape) with 1mm depth and 1cm diameter cylindrical flat "hat" attached upon.

Base constraints: zero displacements, zero rotation

On the top is applied a costant, mono direction wall shear stress of 200 Pa, so a 0.0157 N of wall shear force (but i don't think it needs for modal analysis).

## Maximum strain from 6000 frames of a step in ABAQUS/Standard

Dear All,

I have the following problem: I'm doing a time history analysis of box-shaped reinforced concrete shear wall. It has four faces, each face consisting of about 400 shell elements. I'm interested in the maximum shear strain that occurs during the whole time history analysis. I'm running this analysis on ABAQUS/Standard and input the time history of accelerations from a file which has a total time of 10.6s @ 0.0018s interval. Apparently, my analysis creates around 6000 frames in one step, corresponding to time history analysis. I would like to plot the maximum shear strain in all the elements on each face.

Dear Colleagues,

## Subset Splitting Digital Image Correlation (SSDIC)

Following our recent article on this new method, we are making our Matlab routines available. The package contains standard DIC, SSDIC, plus a few extras. More info here

## Choice of the analysis for stress relaxation of PBT in real time scale

I am trying to simulate the long term behaviour of the PBT (polybutyelene terephtalate) thermoplastic.

The mesh and initial stress distribution data (after ejection from the mold) were exported from Moldflow commercial program as Abaqus input (*inp) file. By default, I have already got a fist step of the simulation (linear elastic properties of polymer). What I actually need now is to simulate the long-term performance (for example in the interval of hundreds or thousands hours).  It means that the real time scale is of the utmost importance for the analysis.

## Modeling post-tensioned concrete in ABAQUS

Hi All,

I want to model post-tensioning tendons embedded with concrete structure. Both ends of tendons are anchored. Can anyone inform me what kind of element most suitable to model the tendons and concrete structure in ABAQUS? I tried solid part for both items, yet as the tendon diameter is very small if compared to the concrete dimension, the resulting number of mesh on the concrete structure is very large.

I generate a box-like concrete and use the cut extrusion function in ABAQUS to create the ducts at which the tendons are to be located in the Assembly module. The diameter of duct is equal to the diameter of tendon, hence small instances are seeded at the edge of duct end before generating mesh.

## Ansys and 2D/3D in electromagnetics

I have a problem modelling electrical conduction in Ansys. I started with a 2D model where two current excitation sources are applied (one positive and the other negative). I use the potential difference at two opposite points to determine the resistance based on potential drop technique with a square electrode configuration. The problem is that electrical resistance is a reciprocal function of plate thickness, which means that it gets bigger as the plate thickness is reduced. But Ansys gives one number for the electrical resistance and I'm having a hard time comparing it to the theoretical value.

In 3D, I keep getting a resistance that is twice as big as theory predicts. I'd appreciate any assistance.

Hello,

## IOSO optimization benchmarking from Japan

Dear Colleagues,

Our company, the leader provider of Global Optimization Software based on unique Optimization technology IOSO, regularly takes the opportunity to test their software on well-known, special and in-house benchmarks. With the help of famous scientists using our software, our partner companies and our representatives as well as our customers we are ready to show that IOSO is capable to solve various types of optimization tasks coming from various sources.

## SIMULIA announces new features in Abaqus 6.10

For those of you looking for FSI simulation on Abaqus platform, recently Simulia has announced the new features in release 6.10, which introduces the capability for performing Computational Fluid Dynamics (CFD) simulation.
So it enables users to perform coupled physics simulations with
Abaqus/Standard and Abaqus/Explicit, such as fluid-structure
interaction between human tissue, a medical device, and fluid flow, more information:

## Abaqus software....... Acoustic-structural interaction

how to take interaction for acoustic -structural interaction in Abaqus software...  I am going to do frequency analysis, plz help

## How to analyze a "RepRap" design (static and vibrational)?

Folks,

I'm embarking on a project to build a modified copy of a DIY 3D printer.  See http://reprap.org/wiki/WebHome to get a rough idea.  In my case, I have my own lathe and milling machine, so I can fabricate more substantial components, e.g., by machining aluminum.  I also have larger stepper motors, some 3/8" precision rod and linear bearings that I can use.

The goal is to design a 3D gantry that will sweep roughly an 8" cube and mount alternate tool heads, e.g., a lightweight  plastic extruder, as well as heavier and higher vibration machining heads (~Dremel motor).  I would like to design the gantry to minimize static and vibrational deflection, while minimizing weight.

## which software for impact/destructive simulation?

Hi,

I am evaluating a couple of software packages for impact and destructive testing simulation.

What are the strength and weakness of the following packages in terms of explicit solver capability for impact/destructive?

NX Nastran non-linear (with explicit solver)

NEi Nastran explicit

ANSYS explicit solver (new in ANSYS 12)

Thanks!

phsieh2005

## FEM method for PDE

Hi all,

I want to solve one second order nonlinear partial differential equation. Please see attachment for PDE.

any FEM solver is avilable to solve this PDE.

Alok

Hi All,

## Structural thermal analysis in ANSYS

How can we perform first structural and then thermal analysis in ANSYS (version 12) ? All the examples show the sequence the other way. I can't go for Direct coupled method as the materials are elastic-plastic (plasticity is not supported by direct coupling elements).

## anyone using mupad & matlab

Hi all!

I'm using Matlab and mupad  in my research .I have managed to plot a few curves using mupad, a powerful symbol computation soft. Since it is theory solution, I want to add the experimental curves to compare the goodness.But i don't how to make the two softwares work cooperated.

Any suggestions will be appreciate.

(Forgive my poor English^_^)

haiwei zhang

## analysis buckling of FGM cylindrical shell with abaqus

i am analyzing of fgm cylindrical shell that chang property in the thickness.

i want use abaqus subrotine or other sutable sofware.

can you help me?

## OpenTURNS: Open source initiative to Treat Uncertainties, Risks’N Statistics

For those who work in the field of uncertain mechanics, please have a look at OpenTURNS. Wrappers to link your favorite code are easy to built.

OpenTURNS

What is OpenTURNS ?

OpenTURNS is an Open source initiative to Treat Uncertainties, Risks’NStatistics in a structured industrial approach.

## Webinar on AxSTREAM 3.0: Design of Multispool Axial Compressor. From Specification to 3D Blade Design

On May 27, 2010, at 10 a.m. and 4 p.m. EST SoftInWay will hold free webinar "AxSTREAM 3.0: Design of Multispool Axial Compressor. From Specification to 3D Blade Design".

In the course of the 1-hour online presentation, the SoftInWay team will showcase the new features of AxSTREAM 3.0 for multispool compressors, namely:

1.  Ability to assess multiple criteria to choose the optimal flow path design.
2.  Flow path geometry adjustment according to designer's goals (using manual and S1 adjustment and spline).
3.  Simulation of flow path to produce the required design including ducts, heat exchanger, pressure valves etc.
4.  1D/2D calculation and optimization of flow path shape.

## Geometry&FEM connection in Mechanical APDL (ANSYS)

Hello everbody,

I'm mechanical engineer and working as FEA Engineer in GATES. I have
been using ANSYS for 5 years and I want to ask a question about new
version of ANSYS.

I use ANSYS Mechanical 12.1. I connect "geometry" and "setup" to
Mechanical APDL box in "project schematic". Then when I open Mec. APDL, I
can see the cad model (areas, lines, volumes) and FEM (nodes, elements)
but they aren't connected to each other. is there any way to connect
solid model to finite element model?

Best Regards.
Mehmet.