3D Experimental Measurements in Soft Materials - from measuring cell displacement fields to complex hierarchical material deformations and beyond
The Why? - Why do we need 3D material deformation measurement?
This is an excellent question. If material surface deformation field descriptions are of prime interested, then Digital Image Correlation and interferometry techniques provide the user with a mature field available experimental approaches that might fit the bill . However, if the material of interest presents itself with an internally non-homogenous, non-periodic or simply 3D microstructure, 3D internal deformation measurement techniques might be the only way to investigate the material’s deformation, and ultimately its constitutive behavior.
I have aproblem with contact peoblem.
I am working in indentation in composite laminate plate the simulation was done using ANSYS. i define surface to surface contact between the rigid indneter and the laminate plate. then, a small displacemnt is applied to the indenter (.005mm) to check the conatct condition.
when applying this small displacemnt i get very large penetration of indneter in the specimen. and i don't know why?
If any one can help me?
Molecular dynamics (MD) method is an important simulation tool, but its results are always doubtful due to its unrealistic high strain rates. In this paper, a hybrid quasi-static atomistic simulation method at finite temperature is developed, which combines the advantages of MD for thermal equilibrium and atomicscale finite element method (AFEM) for efficient equilibration. Some temperature effects are embedded in static AFEM simulation by applying the virtual and equivalent thermal disturbance forces extracted from MD. Alternatively performing MD and AFEM can quickly obtain a series of thermodynamic equilibrium configurations such that a quasistatic process is modeled.
I need this book highly.
anyone have PDF of this book?
"Impact strength of materials" by W.Johnson
The postdoc position is mainly focused on
development of advanced computational models of microstructure evolution
in metallic materials, with particular focus on recrystallization and
related phenomena. Some experimental activities may also be part of the
The employment is for one year with a possible extension to two years.
A more detailed job description and procedures for
application can be found here .
I want to use an external subroutine in my umat but I have not been able to do that so far. Having created a dynamic library project in Visual Studio 2008, I have created a .dll and .lib files and copied the .lib file into the working directory of my abaqus job and the .dll file to exec folder. I have also added the directory of the .lib file in the LIB environmental variable. But I get these errors from ABAQUS:
Here you can find a sample codes along with documentation:
At the end of the page there is the link.
I am performing a nonlinear analysis (ANSYS) of GRP pipe which is subjected to diametral compression ,
i am appling a line load in steps of 0.05 increments until load reaches a maximum value of 40kN in 20 steps
i have got convergence till 13 steps but unable to get convergence in next further steps , i am getting error as LSSOLVE looping is stopped because solution is unconvergent and NCNV, 1set
could any1 come forward and tell me how to fix this error so that i can get convergence
Thank you all
I'm quite sure we can use Python read displacement and load for certin node set from Abaqus odb result file and then plot X-Y data (That's all I need). I has been struggling for a whole week to find out a good solution. I've many resources out there but nothing has been worked out though. So, I wonder if anyone knows how to address this issue or even share me a link. I really appreciate it!
I have a problem now:
I simulated indentation on a elastic-plastic model with a rigid
indenter, the elastic ideal plastic with von mises stress model in
ABAQUS is used. A contact pair is applied to calculate the contact between the indenter and the sample.
The problem is that the obtained the force-displacement data in the loading part, which contains the plastic deformation
is not smooth, but in the unloading part is smooth. But if a model
without plastic is used, the force-displacement data is smooth.
I have tried to use a finer mesh and finer calculation increament step, but both method don't work.
I'm working on UEL. The stiffness matrix (AMATRX) which I have
defined is consisting of complex numbers (real and imaginary part).
When I'm running it I'm getting this error message:
Abaqus Error: The executable standard.exe aborted with system
error code 1073741819. Please check the .dat, .msg and .sta files for
error messages if the files exist. ...
I checked the files and no error message was found.
When stiffness matrix is just real numbers, it's working perfectly.
Would you please let me know what should I do?
Thanks in advance.
Hi, i have a simple problem.
Postdoctoral researcher position opening at Pohang University of Science and Technology (POSTECH), KoreaSubmitted by Trung N Nguyen on Thu, 2014-03-06 09:44.
We are seeking a highly qualified candidate for a full-time postdoctoral researcher position in the area of Computational Mechanics at the Graduate Institute of Ferrous Technology (GIFT), Pohang University of Science and Technology (POSTECH), Korea. Candidates with a strong background in continuum/dislocation-based plasticity theory, computational mechanics of sheet metals, FE modelling of sheet metal forming processes… are highly encouraged to apply.
PhD Position in Nanomechanics and applied Nanotechnology at the Norwegian University of Science and Technology (NTNU), NorwaySubmitted by Zhiliang Zhang on Thu, 2014-03-06 08:23.
NTNU Nanomechanical Lab at the Norwegian University of Science and Technology (NTNU) is looking for a PhD candidate within the field of Nanomechanics-nanotechnology-enabled petroleum engineering. The position is part of a knowledge-building project financed by The Research Council of Norway and industrial partners. The goal of the project is to design and control nanoparticles enabling interfacial wettability alteration and enhanced flow transport in confined space towards petroleum applications through multi-scale experiments and simulations. The PhD candidate will work closely with other specialists involved in the project. Details about the PhD salary and requirements can be seen from the attached annoucement.
Complex Ordered Patterns in Mechanical Instability Induced Geometrically Frustrated Triangular Cellular StructuresSubmitted by Sung Hoon Kang on Wed, 2014-03-05 19:29.
We have studied how complex ordered patterns can appear from buckling-induced geometrically frustrated triangular cellular structures.
The paper is selected as the Physical Review Letters Editors' Suggestion and highlighted in Physics Synopsis as the link below.
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Earth science: Missing link in mantle dynamics
Disclinations provide the missing mechanism for deforming olivine-rich rocks in the mantle
I want to simulate loading of 2D RVE of dual phase steels, by giving individual phases properties, to get homogenised mechanical properties like yield strength, % elongation etc, using micromechanics based approach. Litterature shows people have used two kinds of boundary condition viz. Periodic boundary condition and homogenous boundary condition for this case. My doubt is two folds:
1) What is the theoretical difference between these two kinds of boundary conditions?
2) how to apply these boundary conditions in a finite element framework, along with loading?. Specifically, I am interested to know what are the boundary condition on the 4 corner nodes of RVE, and how to apply loading?
Thnks in advnce,
Can someone explain the strange physical behavior in contact problem using Lagrange method in modeling a simple 2D indentation?Submitted by minhtran.1986.vn on Wed, 2014-03-05 13:33.
I am modelling a very simple 2D contact problem between a rigid indenter and a deformable squared-shape specimen. I used a implicit function f to describe the rigid indenter.
The contact condition is: Inside the contact zone of the deformable specimen, a node n is outside of rigid indenter for f(n)>0, and inside for f(n)<0. In case f(n)=0, the contacting node lies on the surface of the rigid body.
The critical buckling load is given by Pcr=n2 * (pi2 * E*I)/L2 where L is effective length.But what does the n refer to?Is it the number of buckling modes we want to see or some numbers depending upon the end fixity conditions?
The group of Composite Materials and Dynamics Lab at the University of Arkansas at Little Rock has one opening for a Ph.D. scholarship in the field of mechanics of metamaterials and structural health monitoring. The appointment is to commence in Fall 2014 or as early as possible.
Equivalent degree in solid mechanics, mechanical engineering, or material science is needed. Talented applicants with a B.S. degree in the above field will also be considered. Interested applicants are welcome to send a resume to Dr. Guoliang Huang (http://www.ualr.edu/glhuang) at firstname.lastname@example.org. The application will be accepted immediately until the position is filled.
I did a 2D beam bending problem with CST and Q4 element, respectively. CST gives better accuracy. Is it due to the shear locking effect with Q4?