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Stabilization method in local instability problems

Dear all,

 in commercial FE codes, such as ABAQUS, ANSYS, there is option to get convergence in quasi-static analysis by using artificial damping factor. I tried to dig their documentation about this method, but it is somewhat sparse. Could some body recommend me some literature about this topic so that I can gain a better understanding about it.

 

I thank you in advance.

 

Sincerely yours,

Ken 

Oleg Kirillov's picture

Nonconservative Stability Problems of Modern Physics

This monograph gives a complete overview on the subject of nonconservative stability from the modern point of view. Relevant mathematical concepts are presented, as well as rigorous stability results and numerous classical and contemporary examples from mechanics and physics.

Stephan Rudykh's picture

Wrinkling of Interfacial Layers in Stratified Composites

by Y. Li, N. Kaynia, S. Rudykh and M. C. Boyce

 Massachusetts Institute of Technology 

 Abstract:

 

zichen's picture

Postdoctoral research associate position in mechanics of materials, morphogenesis and biosinspired structures

One postdoctoral research associate position is available (dates negotiable). The successful candidate will work on one or multiples of the following topics: mechanics of morphogenesis in plants and embryos, fast motion of plants (e.g., the Venus flytrap's rapid closure), mechanical self-assembly and instability of thin structures (e.g., DNA, plant tendrils, self-assembly of nanostructures, etc.), and bioinspired structures. The candidate should have received (or expect to receive very soon) a Ph.D.

Bo Li's picture

Modeling of the muscle-like actuation in soft dielectrics: deformation mode and electromechanical stability

Soft dielectric elastomer is able to generate an
electromechanical response in terms of reversible shape
changing, which is a muscle-like behavior. The deformation
and electromechanical stability of dielectric elastomers,
classified by their deformation modes, uniaxial extension,
equal biaxial expansion and pure shear, are investigated.
Pull-in instability occurs in equal biaxial and uniaxial modes
at a small stretch ratio, while the pure shear mode features
wrinkling instability after a large stable deformation. The

Davide Bigoni's picture

Effects of the constraint’s curvature on structural instability: tensile buckling and multiple bifurcations

Choose a channel featured in the header of iMechanica: 

Can a single-degree-of-freedom elastic structure have two buckling loads?

We provide a positive answer to this question, see http://www.ing.unitn.it/~bigoni/multiple_bifurcations.html

 

Bo Li's picture

Effect of temperature on the stability of dielectric elastomers

Dielectric elastomer (DE) is a kind of electroactive polymer material,
capable of large deformation up to 380%. However, under conservative
operating conditions, DE is susceptible to instability with a small
deformation due to various modes of failure, including electrical
breakdown, electromechanical instability (EMI), loss of tension and
rupture by stretch. This paper proposes a free energy model in the
thermodynamic system of DE involving thermoelastic strain energy,
electric energy and purely thermal contribution energy to obtain the
stability conditions of all failure modes. The numerical results
indicate that the increase in temperature can markedly contribute to
improving the entropy production, the actuation stress and the critical

Davide Bigoni's picture

Can an elastic structure buckle under tensile dead load?

Choose a channel featured in the header of iMechanica: 

We all know Euler buckling of a beam under axial thrust, but can buckling occur in an elastic structure in which all elements are subject to tensile dead loading?

We provide a positive answer to this question, see http://www.youtube.com/user/RoyalSociety#p/u/0/EKngs1vvcJU

 

Davide Bigoni's picture

Can an elastic structure buckle under tensile dead load?

We all know Euler buckling of a beam under axial thrust, but can buckling occur in an elastic structure in which all elements are subject to tensile dead loading?

We provide a positive answer to this question, see http://www.youtube.com/user/RoyalSociety#p/u/0/EKngs1vvcJU

 

PhD positions in Computational Mechanics

We are looking for suitable candidates for a PhD research work in Computational Mechanics and numerical simulation, to be carried out at the Department of Mechanical Engineering, University of Aveiro, Portugal, in one of the following areas:

- development of new finite elements for metal forming applications;

- numerical simulation of metal forming (sheet and bulk forming);

- tubular hydroforming numerical simulation;

- structural stability and buckling analysis of reinforced aircraft panels;

Rui Huang's picture

Effects of mismatch strain and substrate surface corrugation on morphology of supported monolayer graphene

In a previous work, substrate-modulated morphology of graphene was analyzed using a numerical Monte Carlo method. Here we present an analytical approach that explicitly relates the van der Waals interaction energy to the surface corrugation and the interfacial properties. Moreover, the effect of mismatch strain is considered, which predicts a strain-induced instability under a compressive strain and reduced corrugation under a tensile strain.

Teng Li's picture

Snap-through instability of graphene on substrates

T. Li, Z. Zhang, Snap-through instability of graphene on substrates, Nanoscale Research Letters,DOI: 10.1007/s11671-009-9460-1 (2009). (Open access)

Wei Hong's picture

Formation of creases on the surfaces of elastomers and gels

When a block of an elastomer is bent, the compressed surface may form a crease. This paper analyzes the critical condition for creasing by comparing the elastic energy in a creased body and that in a smooth body. This difference in energy is expressed by a scaling relation. Critical conditions for creasing are determined for elastomers subject to general loads and gels swelling under constraint. The theoretical results are compared with existing experimental observations.

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