Search results for "BEM"
showing 10 items of 133 documents
Boundary Element Method for Composite Laminates
2017
The boundary element method (BEM) is a numerical technique to solve engineering/physical problems formulated in terms of boundary integral equations. Composite laminates are assemblages of stacked different materials layers, generally consisting of variously oriented fibrous composite materials
Determination of Torsional Stresses in Shafts: From Physical Analogies to Mathematical Models
2015
This paper presents the historical development of methods used for the study of torsional stresses in shafts. In particular, the paper covers both analog methods, especially those based on electrical analogies proposed circa 1925, and numerical methods, especially finite difference methods (FDM), finite element methods (FEM) and boundary element methods (BEM).
Elastoplastic analysis by active macro-zones with linear kinematic hardening and von Mises materials.
2014
In this paper a strategy to perform elastoplastic analysis with linear kinematic hardening for von Mises materials under plane strain conditions is shown. The proposed approach works with the Symmetric Galerkin Boundary Element Method applied to multidomain problems using a mixed variables approach, to obtain a more stringent solution. The elastoplastic analysis is carried out as the response to the loads and the plastic strains, the latter evaluated through the self-equilibrium stress matrix. This matrix is used both, in the predictor phase, for trial stress evaluation and, in the corrector phase, for solving a nonlinear global system which provides the elastoplastic solution of the active…
CVBEM solution for De Saint-Venant orthotropic beams under coupled bending and torsion
2014
The aim of this paper is to provide a solution for the coupled flexure–torsion De Saint Venant problem for orthotropic beams taking full advantage of the complex variable boundary element method (CVBEM) properly extended using a complex potential function whose real and imaginary parts are related to the shear stress components, the orthotropic ratio and the Poisson coefficients. The proposed method returns the complete stress field and the unitary twist rotation of the cross section at once by performing only line integrals. Numerical applications have been reported to show the validity and the efficiency of the proposed modified CVBEM to handle shear stress problems in the presence of ort…
CVBEM application to a novel potential function providing stress field and twist rotation at once
2013
AbstractIn this paper, complex variable boundary element method (CVBEM) is used for the solution of de Saint-Venant’s torsion problem in homogenous isotropic elastic beams with a generic cross section, considering a complex potential function related to the stress field. Generally, CVBEM, when used for torsion problems, leads to evaluation of the stress field divided by the twist rotation. The latter has been evaluated by performing a domain integral. In this paper, taking advantage of the aforementioned potential function, it is possible, by applying CVBEM, to evaluate the complete stress distribution and the twist rotation of the cross section and the torsional stiffness factor, performin…
Akūtas mezenteriālās išēmijas iznākumu analīze
2018
Aktualitāte. Akūta mezenteriālā išēmija ir smaga vēdera dobuma patoloģija. Slimība ir raksturīga vecāka gadagājuma cilvēkiem, bet sakarā ar populācijas novecošanos, akūtu mezenteriālu išēmiju arvien biežāk sastop klīniskajā praksē. Mirstība pie akūtas mezenteriālās išēmijas sasniedz 70 – 100%. Materiāli un metodes. Retrospektīvā pētījumā tika iekļauti 145 slimnieki ar akūtu mezenteriālu išēmiju, kuri ārstējas RAKUS stacionārā “Gaiļezers” periodā no 01.01.2011. līdz 31.12.2015. Tika veikta medicīniskās dokumentācijas analīze un datubāzes izveidošana. Tika iegūti slimnieku demogrāfiskie dati un dati par anamnēzes ilgumu, simptomiem, laboratorisko izmeklējumu rezultātiem, pielietotām ārstēšana…
Multidomain Symmetric Galerkin BEM for non-linear analysis of masonries in-plane loaded
2014
The preservation of the historical and monumental buildings, but also of the considerable heritage of old constructions made by traditional techniques, is one of the actual problems of the structural mechanics. The level of knowledge of their structural behavior in presence of external actions is made through calculus methods and simple procedures in order to allow a reading of the material suffering degree and as a consequence of the related safety. In this paper an elastic analysis of walls, also in presence of geometrical nonlinearity consisting in the contact/detachment phenomenon among stone blocks. The wall having any shape and zone-wise variable physical characteristics is loaded in …
Frctionless contact: step by step analysis and mathematical programming technique
2011
The object of the paper concerns a consistent formulation of the classical Signorini's theory regarding the frictionless unilateral contact problem between two elastic bodies in the hypothesis of small displacements and strains. A variational approach employed in conjunction with the Symmetric Boundary Element Method (SBEM) leads to an algebraic formulation based on generalized quantities [1]. The contact problem is decomposed into two sub-problems: one is purely elastic, the other pertains to the unilateral contact conditions alone [2,3]. Following this methodology, the contact problem, by symmetric BEM, is characterized by symmetry and sign definiteness of the coefficient matrix, thus adm…
Computational aspects in 2D SBEM analysis with domain inelastic actions
2009
The Symmetric Boundary Element Method, applied to structures subjected to temperature and inelastic actions, shows singular domain integrals. In the present paper the strong singularity involved in the domain integrals of the stresses and tractions is removed, and by means of a limiting operation, this traction is evaluated on the boundary. First the weakly singular domain integral in the Somigliana Identity (S.I.) of the displacements is regularized and the singular integral is transformed into a boundary one using the Radial Integration Method; subsequently, using the differential operator applied to the displacement field, the S.I. of the tractions inside the body is obtained and through…
Harmful Interference of Detoxifying Diets and Nutraceuticals with Adherence to Abemaciclib in Advanced Estrogen Receptor-Positive, Human Epidermal Gr…
2021
Many cancer patients use integrative therapies with a combination of natural products and diets. In the Western world, integrative medicine is often not shared with oncologists even during antineoplastic treatments. This behavior stems from the unmet needs of cancer patients who may feel oncologists’ underestimation of their symptoms and spiritual aspects. This case report demonstrates the potential harm of inadequate diet and nutraceutical intake in a 68-year-old woman with metastatic estrogen receptor-positive, human epidermal growth factor receptor-2-negative breast cancer. Her care team recommended hormone therapy with abemaciclib plus fulvestrant. Her diarrhea started after 10 days of …