Search results for " BEM"
showing 10 items of 39 documents
A fast BEM for the analysis of damaged structures with bonded piezoelectric sensors
2010
A fast boundary element method for the analysis of three-dimensional solids with cracks and adhesively bonded piezoelectric patches, used as strain sensors, is presented. The piezoelectric sensors, as well as the adhesive layer, are modeled using a 3D state-space finite element approach. The piezoelectric patch model is formulated taking into account the full electro-mechanical coupling and embodying the suitable boundary conditions and it is eventually expressed in terms of the interface variables, to allow a straightforward coupling with the underlying host structure, which is modeled through a 3D dual boundary element method, for accurate analysis of cracks. The technique is computationa…
O modelo da economia do bem comum: abordagem a partir da abordagem organizacional e análise bibliométrica
2019
Resumen El trabajo tuvo por objeto realizar una aproximación al modelo de la economía del bien común desde la organización de empresas, así como desde un análisis bibliométrico. Se realizó una comparación entre el enfoque empresarial de la economía del bien común y dife- rentes teorías organizativas: recursos y capacidades, stakeholders y creación de valor compartido. Mediante el análisis bibliométrico, se identificaron los trabajos publicados sobre la economía del bien común desde su surgimiento en 2010 hasta 2018, mediante búsqueda realizada en Web of Science y Dialnet. Se demuestra que su enfoque empresarial está relacionado con diferentes teorías de la organiza- ción de empresas y que a…
A fast 3D BEM for anisotropic elasticity based on hierarchical matrices
2008
In this paper a fast solver for three-dimensional anisotropic elasticity BEM problems is developed. The technique is based on the use of hierarchical matrices for the representation of the collocation matrix and uses a preconditioned GMRES for the solution of the algebraic system of equations. The preconditioner is built exploiting the hierarchical arithmetic and taking full advantage of the hierarchical format. The application of hierarchical matrices to the BEM solution of anisotropic elasticity problems has been numerically demonstrated highlighting both accuracy and efficiency leading to almost linear computational complexity.
Statin intolerance: new data and further options for treatment
2021
Purpose of review Hypercholesterolemia is a major risk factor for cardiovascular diseases. Administration of statins represents the cornerstone of the prevention and treatment of cardiovascular disease, with demonstrated long-term safety and efficacy. This review aims to revisit statin intolerance mechanisms, as well as to discuss new data and therapeutic options. Recent findings Although statins are well tolerated, myopathy and other adverse effects are a challenging problem, being the main reason for poor adherence to treatment and failure in lowering cardiovascular risk. Statin intolerance is the subject of ongoing research, as these drugs are widely used. There are alternative options o…
MACRO-ZONES SGBEM APPROACH FOR STATIC SHAKEDOWN ANALYSIS AS CONVEX OPTIMIZATION
2013
A new strategy utilizing the Multidomain SGBEM for rapidly performing shakedown analysis as a convex optimization problem has been shown in this paper. The present multidomain approach, called displacement method, makes it possible to consider step-wise physically and geometrically nonhomogeneous materials and to obtain a self-equilibrium stress equation regarding all the bem-elements of the structure. Since this equation includes influence coefficients, which characterize the input of the quadratic constraints, it provides a nonlinear optimization problem solved as a convex optimization problem. Furthermore, the strategy makes it possible to introduce a domain discretization exclusively of…
A fast dual boundary element method for 3D anisotropic crack problems
2009
In the present paper a fast solver for dual boundary element analysis of 3D anisotropic crack problems is formulated, implemented and tested. The fast solver is based on the use of hierarchical matrices for the representation of the collocation matrix. The admissible low rank blocks are computed by adaptive cross approximation (ACA). The performance of ACA against the accuracy of the adopted computational scheme for the evaluation of the anisotropic kernels is investigated, focusing on the balance between the kernel representation accuracy and the accuracy required for ACA. The system solution is computed by a preconditioned GMRES and the preconditioner is built exploiting the hierarchical …
Strain gradient elasticity within the symmetric BEM formulation
2014
The symmetric Galerkin Boundary Element Method is used to address a class of strain gradient elastic materials featured by a free energy function of the (classical) strain and of its (first) gradient. With respect to the classical elasticity, additional response variables intervene, such as the normal derivative of the displacements on the boundary, and the work-coniugate double tractions. The fundamental solutions - featuring a fourth order partial differential equations (PDEs) system - exhibit singularities which in 2D may be of the order 1/ r 4 . New techniques are developed, which allow the elimination of most of the latter singularities. The present paper has to be intended as a resear…
On the accuracy of the fast hierarchical DBEM for the analysis of static and dynamic crack problems
2010
In this paper the main features of a fast dual boundary element method based on the use of hierarchical matrices and iterative solvers are described and its effectiveness for fracture mechanics problems, both in the static and dynamic case, is demonstrated. The fast solver is built by representing the collocation matrix in hierarchical format and by using a preconditioned GMRES for the solution of the algebraic system. The preconditioner is computed in hierarchical format by LU decomposition of a coarse hierarchical representation of the collocation matrix. The method is applied to elastostatic problems and to elastodynamic cases represented in the Laplace transform domain. The application …