research
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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Dear 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?
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.
Conformability of a Thin Elastic Membrane Laminated on a Soft Substrate With Slightly Wavy Surface
Conformability of a Thin Elastic Membrane Laminated on a Soft Substrate With Slightly Wavy Surface
Liu Wang, Nanshu Lu*
Modelling cyclic behaviour of soil using UMAT
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I have been trying to model the cyclic behaviour of soil. I got a UMAT. But when I'm using UMAT, it is creating lot many errors (like numerical singularity and excessive distortion). I have constrained it properly. I tried running my model with an inbuilt material (clay plasticity) and I'm getting results. Here I'm not even able to move from the initial geostatic step. Can anyone please help
Interalaminar damage model
Dear iMechanicas,
I need advices from experts regarding choosing a proper interalaminar damage model for the implementation into the theory of plates and shells. I am going to apply a failure criterion which is straight forward but concerning the degradation procedure of material properties I may need some suggestions.
Best regards,
r_n_s_s
PhD Student Position in Mechanical Properties of Materials at the Micron Scale
Job description: We are seeking innovative and highly motivated PhD candidates to join the FROG lab in the mechanical engineering department at the University of Ottawa.