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SavanRGowda's picture

Abaqus Fortran Subroutine

Hi Everyone,

I have now managed to run the fortran code, but it won't assign the values that I want to assign to the U(1) variable from the TXT file.

In the attached file I have the Fortran file that I am working on, the input file Subroutine1 (save it as .inp file to open in Abaqus) and the pressure file that contains the nodes and the corresponding pressure values which I want to assign through DISP Subroutine. The code below

      SUBROUTINE DISP(U,KSTEP,KINC,TIME,NODE,NOEL,JDOF,COORDS)

ahmed.hussein's picture

Surface roughness evolution during early stages of mechanical cyclic loading

The effect of crystal size and initial dislocation density on surface roughness evolution in FCC single crystals during the early number of cycles of mechanical cyclic loading is investigated using three dimensional discrete dislocation dynamics simulations. Crystals having size less than 2 μm show early development of surface slip localization, while larger ones show a more uniform distribution of surface steps. The surface roughness is found to increase with increasing number of loading cycles with larger crystals showing a high roughening rate compared to smaller crystals.

Post-doctoral fellow at University of California San Francisco Medical Center and San Francisco VA

The Cardiac Biomechanics Laboratory at the University of California San Francisco Medical Center (UCSF) Division of Cardiothoracic Surgery and San Francisco VA Medical Center is seeking a hard working, motivated post-doctoral fellow to participate in biomedical engineering research involving the ascending thoracic aortic aneurysms (aTAA).  The post-doctoral fellow should be motivated to be on a career track to become an academic professor.  Our lab is NIH funded to investigate the biomechanics of aortic aneurysms and currently has 2 postdoctoral fellows, and are seeking a 3rd.  The goals ar

Shaoxing Qu's picture

Journal Club Theme of March 2016: When mechanics meets medicine in the new age

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Shaoxing Qu

Department of Engineering Mechanics, Zhejiang University, China

Introduction

Applied Mechanics Division – Haythornthwaite Foundation Research Initiation Grants 2016

With funding from the Haythornthwaite Foundation, the Executive Committee (EC) of the Applied Mechanics Division (AMD) of ASME is pleased to announce the establishment of the Haythornthwaite Research Initiation Grant Program, targeting university faculty engaged in research in theoretical and applied mechanics that are at the beginning of their academic careers. Applicants must hold a tenure‐track appointment at the rank of Assistant Professor at a US university on October 1, 2016, and must not be more than 5 years beyond receipt of their doctoral degree at the time the award is made.

jorgegdiaz's picture

SIF analytic Solution (Mode I and/or II) for Tubes

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I was wondering if anyone knows of an analytic Solution for KI and/or KII in tubes.

I´ve seen an infinite number of equations, shape functions, FEM simulations, standards, etc. But one closed solution for tubes?, an analog to Williams series but for cilindirical surfaces?

I am trying to fit experimental displacement data to Williams series. I´ve done it succesfully for flat specimens (kind of easy actually). But now, we have to do the same for tubes. When cracks are long, you can´t approximate the tube surface to an infinite plate anymore.

ahmedettaf's picture

Dynamic friction in sheared fault gouge: implications of acoustic vibration on triggering and slow slip†

Friction and deformation in granular fault gouge are among various dynamic interactions associated with seismic phenomena that have important implications for slip mechanisms on earthquake faults. To this end, we propose a mechanistic model of granular fault gouge subject to acoustic vibrations and shear deformation. The grain-scale dynamics is described by the Shear-Transformation-Zone theory of granular flow, which accounts for irreversible plastic deformation in terms of flow defects whose density is governed by an effective temperature.

How do you solve the system error code 1073741819 in Abaqus 6.12?

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Hi I am getting this error message while running a UELMAT:

S. Beretta's picture

Fatigue design and maintenance of railway axles

The ESIS Technical Committee 24 provides a forum for researchers and engineers who deal with structural integrity problems in modern railway system. During our latest meeting, held on 1-2 October 2014 at Politecnico di Milano, excellent talks presented results obtained within different research projects, including  EURAXLES - EBFW3  and SUSTRAIL.

Usermat: Linear viscoelastic model with geometric nonlinearity

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Hello,

I have implemented a linear viscoelastic model using the user subroutine Usermat in Ansys.
I have used the classical paper: "Formulation and implementation of three-dimensional viscoelasticity at small and finite strains" of Kaliske & Rothert (Simo's approach) and it works fine for small deformations.

It is written in the documentation that in the case of a simulation with large strain (geometric nonlinearity), one must rotate the state variables.

mohsenzaeem's picture

The anisotropy of hexagonal close-packed and liquid interface free energy using molecular dynamics simulations based on modified embedded-atom method

This work aims to comprehensively study the anisotropy of the hexagonal close-packed (HCP)-liquid interface free energy using molecular dynamics (MD) simulations based on the modified-embedded atom method (MEAM). As a case study, all the simulations are performed for Magnesium (Mg). The solid-liquid coexisting approach is used to accurately calculate the melting point and melting properties. Then, the capillary fluctuation method (CFM) is used to determine the HCP-liquid interface free energy and anisotropy parameters.

vrh59ir's picture

Local radial point interpolation (MLRPI) method for solving time fractional diffusion-wave equation with damping

The purpose of the current investigation is to determine numerical solution of time-fractional diffusion-wave equation with damping for Caputo's fractional derivative of orderα(1<α≤2).

Karol Frydrych's picture

Polycrystal plasticity in Abaqus/Explicit

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Hello everyone!

My goal is to model large plastic deformations of polycrystalline metals using crystal plasticity and ALE adaptive meshing. In order to do that I want to use VUMAT subroutine in Abaqus/Explicit, since as far as I understand Abaqus/Standard is not good for large deformations and it doesn't support ALE adaptive meshing for that purpose.

anand_mtech's picture

Injection_mass.PROF for combustion simulation in ANSYS

Dear All,

Please help me in finding Injection_mass.PROF file for combustion simulation in ANSYS ICE, 

 

Thanking you,

Anand.A

Yonggang Huang's picture

A perspective paper on flexoelectricity by Prof. Pradeep Sharma

A perspective paper on flexoelectricity by Professor Pradeep Sharma (University of Houston) is published in the March (2016) issue of the Journal of Applied Mechanics.  A perspective paper describes an important, emerging field in mechanics.  The first perspective paper, by Professor Huajian Gao (Brown University), has been downloaded more than 8000 times since its publication.  This new paper by Professor Sharma is the 3rd perspective paper published in JAM.  The paper is attached.

Orthogonality and closure relations in Stroh formalism

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Orthogonality reationDear iMechanica members,

I deal with exteded Stroh formalism for piezoelectric media. I have problems with orthogonalization of Stroh´s matrices A, B, respectively how to fulfil the ortogonality relations (see attachments). I tried to "rape" it and made the left matrix inverse of the right matrix (then the product is an unit matrix) and I became very similar singularity expomemt as in the paper

VUMAT Algorithm for writing Cockcroft Lathom model

Can someone advise me the algorithm for writing VUMAT for C-L model? I have doubts mainly in following steps.

1. Will Elastic and plastic predictor step be similar as isotropic hardening model given in VUMAT example pdf?

2. How to couple damage prediction steps?

Ramathasan Thevamaran's picture

A few experimental studies on the dynamic behavior of foam-like aligned carbon nanotubes

I'm posting a few experimental studies we have conducted on the dynamic behavior of hierarchical fibrous materials, using vertically aligned carbon nanotubes as a model material. I hope these will be useful to those who are interested in buckle-instabilities, multiscale behavior, and energy absorption mechanisms.

An overview:

Localized compliance with Castigliano's theorem

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I'm attempting to compile a local compliance matrix using Castigliano's theorem as described here. I'm having trouble with it and attempted to do a simple example by hand and picked the double cantilever beam specimen and analyzed it with Euler-Bernoulli beam theory (attached). Despite my best efforts, I can't reproduce the correct answer using the theorem as is but only if I modify the limits of integration.

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