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ahmed.hussein's picture

Quantifying dislocation microstructure evolution and cyclic hardening in fatigued face-centered cubic single crystals

Discrete dislocation dynamics simulations were performed to investigate the dislocation microstructure evolution and cyclic hardening during the early stages of fatigue loading in nickel single crystals. The effects of the crystal size and initial dislocation densities on both the mechanical response and the evolution of dislocation microstructure were quantified.

Line Spring elements errors

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Hello, All

***Problem ***

Failure pressure for Steam generator tube having 2 axial cracks. I am following one paper in that paper they found failure pressure by finding J and K values for line spring elements for different pressure. The pressure at which it approach material JIC(92N/mm) and KIC(65Mpa*sqrt(m)) value is considered as failure pressure or coalescence pressus


Generate master curve for viscoelasticity

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I would like to generate a master curve (e.g. of the storage modulus) based on frequency-sweeps experiment for different temperatures.

Basically, I need to determine the shifts in order to construct the master curve. I want to automatize the process with Matlab, instead of shifting the data by hand. And I don't want to use WLF or Arrhenius methods.

I want to determine the shifts for each temperature s.t. I get a smooth master curve (minimize the error using least square).

renganathan sekar's picture

How do I rectify an error regarding memory storage when I generate substructures in ABAQUS?

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I have been trying to generate a substructure in ABAQUS for a big diameter roller bearing. I have used two reference points, one each for inner and outer raceways to couple the inner and outer raceway surfaces. I have two steps in the analysis. The first step is Frequency followed by Substructure generation step. The analysis runs fine till the end of first step and calculates the eigen frequencies. When the second step starts, following error message appears.

" Element 439473 requires more than 2GB of memory for storage"

How to analysis Fatigue of shaft using Ansys or Ncode designlife?

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I use ANSYS APDL with code for my shaft with two coating layers(interlayer and coating layer). I already analysis stress of shaft with Ansys. the result is ok and i exported to .RST file. But , when i input my shaft to Ncode, I can't find the interlayer and coating layers.I think this shaft have 3 part(subtrate, interlayer, coating layer)
!substrate materials

Young's modulus (Mpa): 2.1e5
Poisson's ratios:0.3

! interlayer material

sgoel's picture

PDRA opportunity at Cranfield University

I have a fully funded Post-Doc position (PDRA) of 2 years duration to work at Cranfield University,UK looking at an excited FEA modelling project to elucidate details of diamond machining of silicon. The project is financially supported by a world leading Paris based industry. Candidates having good background in solid mechanics/ manufacturing are very much encouraged to write to me at

Yield behaviour of trabecular bone

A recently published paper  "Evaluating the macroscopic yield behaviour of trabecular bone using a nonlinear homogenisation approach" links the micromechanics of bone to its macroscopic behaviour. The paper may be of interest to colleagues on this forum. The abstract is provided below.


Fracto-emission in lanthanum-based metallic glass microwires under quasi-static tensile loading

Plastic deformation in metallic glasses is highly localized and often associated with shear banding, which may cause momentary release of heat upon fracture. Here, we report an explosive fracture phenomenon associated with momentary (∼10 ms) light emission (flash) in Lanthanum-based (LaAlNi) metallic glass microwires (dia. ∼50 μm) under quasi-static tensile loading.

2016 Ted Belytschko Applied Mechanics Award - Professor Andrea Prosperetti

The Executive Committee of the ASME Applied Mechanics Division is pleased to announce and congratulate Professor Andrea Prosperetti, Charles A. Miller, Jr. Distinguished Professor of Mechanical Engineering, Johns Hopkins University, as the recipient of the 2016 Ted Belytschko Applied Mechanics Award.

2016 Thomas J.R. Hughes Young Investigator Award - Professor Pedro M. Reis

The Executive Committee of the ASME Applied Mechanics Division is pleased to announce and congratulate Professor Pedro M. Reis, Gilbert W. Winslow Associate Professor, Massachussetts Institute of Technology, as the recipient of the 2016 Thomas J. R.

Qiming Wang's picture

A Constitutive Model of Nanocomposite Hydrogels with Nanoparticle Crosslinkers

A Constitutive Model of Nanocomposite Hydrogels with Nanoparticle Crosslinkers

Qiming Wang, Zheming Gao


Qiming Wang's picture

Beyond Wrinkles: Multimodal Surface Instabilities for Multifunctional Patterning

Beyond Wrinkles: Multimodal Surface Instability for Multifunctional Patterning

Qiming Wang, Xuanhe Zhao


3 Research Fellowships at University of Southampton for a European Project on Smart Bearings

Looking to take the next step in your academic career? Look no further – three exciting opportunities are available for ambitious researchers to join the UK’s most dynamic research groups for engineering research and education. 

grassl's picture

Damage plasticity model for concrete failure CDPM2

Those involved in the modelling of the failure of plain/reinforced concrete using damage and plasticity might be interested in our webpage

which we have created to support our concrete damage plasticity model CDPM(2) in LS-DYNA. You can find there a number of example input files, reports and our implementation of the model in the form of a user subroutine.


Amit Pandey's picture

Concept of Yield Point or Elastic Limit?

A similar discussion on this forum raised many interesting point about- Stress or strain: which one is more fundamental? 

On a similar note I would like to address this decade old fundamental question on how do we define yield point of a material?  


Viscoelastic damping behavior of structural bamboo material and its microstructural origins

In this study, the intrinsic viscoelastic mechanical behavior of a hierarchical bio-composite, structural bamboo material, was experimentally investigated and correlated with its microstructural constituents and molecular building blocks. The macroscopic viscoelastic responses of bulk bamboo at ambient temperature and dehydrated condition were evaluated through dynamic compression experiments with various loading frequencies, whereas the localized viscoelasticity of bamboo's microstructural phases, viz.

Parallel computing for non-local damage model in abaqus

Hello all,I am simulating epoxy damage using a non-local damage model through abaqus user subroutine UMAT.Based on the idea of Prof. Bazant's non-local treatment, the non-local damage at a particular integration point is obtained by averaging the local damage values of all the integration points within a characteristic length (Lc) of that point.

Modeling with line spring elements to find failure pressure of steam generator tube

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Hello, All
I am trying to model steam generator tube of length 110 , radius 11mm, thickness 1.27mm. It has 2 axial cracks of length 6.35mm. length between 2 cracks is 0.254mm. 

group velocity Vs phase velocity

hi to all,

do anyone know about ultrasonic lamb wave group velocity and phase velocity and differences between them?

I appreciate it.


Arash_Yavari's picture

Finite Eigenstrains in Nonlinear Elastic Wedges

Eigenstrains are created as a result of anelastic effects such as defects, temperature changes, bulk growth, etc., and strongly affect the overall response of solids. In this paper, we study the residual stress and deformation fields of an incompressible, isotropic, infinite wedge due to a circumferentially-symmetric distribution of finite eigenstrains. In particular, we establish explicit exact solutions for the residual stresses and deformation of a neo-Hookean wedge containing a symmetric inclusion with finite radial and circumferential eigenstrains.


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