Bathe's subspace iteration, how to find the largest eigenvalue/mode?
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Does anyone know how to modify Bathe's subspace iteration eigensolver to compute the highest eigenvalue instead of the smallest ?
buckling
Complex Ordered Patterns in Mechanical Instability Induced Geometrically Frustrated Triangular Cellular Structures
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.
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.112.098701
abstract:
Intel MKL LAPACK SBGVX computes a few eigenvalues eigenvectors
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Anyone has an example using this subroutine ?
I have implemented a test pgm as per user manual but i cannot get it to work.
Thanks.
conjugate real eigenvalues
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I have an eigenvalue solver, subspace iteration, that can get only positive eigenvalues. I have a problem (K - lambda M)u=0 that has pairs of eigenvalues +/- lambda. How can I transform the eigenvalue problem for the solver to search for lambda^2 rather than lambda?
Can buckling and instability of a structure be affected by Eshelby forces?
Can buckling and instability of a structure be affected by Eshelby forces?
We provide a positive answer to this question, see http://www.ing.unitn.it/~bigoni/blade.html
Educational iPad app on structural mechanics
I would like to share with fellow mechanicians an educational iPad app I recently developed. The name of the app is Truss Me! and the main goal is to help students, all the way from high school to college, to build intuition on how truss structures behave. The video below highlights some features of the app:
The app utilizes state of the art simulation techniques to provide the most realistic behavior for the structures.
Buckling of an elastically restrained column
How to find a response for a pinned-(pinned+ torsion spring) column with sinusoidal axial load?
I am unable to decouple the equations in space and time using variable separable method, with one end pinned-other end pinned with torsion spring as boundary conditions.
Can anyone please help.
Good day.
--
Rajnish
Subspace Iteration eigenvalues and eigenvectors--efficient implementation?
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Anyone knows an efficient implementation of the subspace iteration method to compute a few lower eigenvalues and eigenvectors of a generalized problem KG*u=lambda*KS*u or any similar method? i.e., to compute the buckling loads and modes.
I'd like to use something optimized to Intel or amd64 processors or similar, like MKL, etc.
This is for bifurcation buckling analysis. KG is the stiffness matrix. KS is the geometric stress matrix. Both constructed from a FEM discretization.
Math Kernel Library MKL
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I want to use Intel Math Kernel Library (MKL) to calculate the bifurcation loads and modes in my custom FE program. MKL has many algorithms and I want to use the most efficient one.
Basically, I need to find a few eigenvalues lambda_i and eigenvectors u_i for the problem
KG * u = lambda * KS * u
where KG is the stiffness matrix and KS is the geometric stiffness matrix, also called stress-displacement matrix.
Is KG supposed to be positive definite?
Basically, I need to find a few eigenvalues lambda_i and eigenvectors u_i for the problem
KG * u = lambda * KS * u
where KG is the stiffness matrix and KS is the geometric stiffness matrix, also called stress-displacement matrix.
Is KG supposed to be positive definite?
