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1

Micromechanical analysis of glass fiber reinforced epoxy composites and case study of macro-mechanical observation

Alam Shahinoor, Chowdhury Mohammad Asaduzzaman

Composites Theory and Practice

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2020

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R. 20, nr 1

23--34

EN

This paper was written and formulated based on the micromechanical analysis of unidirectional glass fiber reinforced epoxy composite lamina. To simplify the calculations and achieve acceptable results, a few assumptions like idealized packing,the representative volume element (RVE), uniform strain boundary condition, statistically homogeneous unidirectional fiber reinforced composites, etc. are taken into consideration. Translational symmetric transformation was applied and established mathematical models are presented to obtain the values of the effective material properties by means of the simple strength of materials approach so that they can be compared with the semi-empirical model. In addition, a parametric study was carried out to verify the dependency of the fiber and matrix on the overall effective material properties. This will ultimately helpto develop the required glass fiber reinforced epoxy composites for their specific applications.

2

The MLPG in gradient theory for size-dependent magnetoelectroelasticity

Sladek J., Sladek V., Hrcek S.

Computer Methods in Materials Science

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2017

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Vol. 17, No. 1

76--82

EN

The strain gradient magnetoelectroelasticity is applied to solve two-dimensional boundary value problems. The electric and magnetic field-strain gradient coupling is considered in constitutive equations. The meshless local Petrov-Galerkin (MLPG) is developed to solve general problems. All field quantities are approximated by the moving least-squares (MLS) scheme. Effective material properties for a piezomagnetic matrix with regularly distributed piezoelectric fibres of a circular cross section and coating layer are presented.

PL

Celem pracy było zastosowanie magneto-elektro-sprężystości charakteryzującej się gradientem odkształceń do rozwiązania problemu brzegowego w domenie 2D. Prawo konstytutywne stanowi problem pól elektrycznego i magnetycznego sprzężonych z odkształceniami. Do rozwiązania ogólnego zadania wykorzystano bezsiatkową lokalną metodę Petrova-Galerkina (ang. the mesh less local Petrov-Galerkin - MLPG). Wszystkie równania pola przybliżono metodą ruchomych najmniejszych kwadratów (ang. the moving least-squares - MLS). Wyznaczono efektywne własności materiałowe dla piezomagnetycznej osnowy z równomiernie rozłożonymi piezoelektrycznymi włóknami o okrągłym przekroju poprzecznym i pokrytych warstwą.

3

Analysis of effective properties of materials by using the boundary element method

Fedeliński P., Górski G., Czyż T., Dziatkiewicz G., Ptaszny J.

Archives of Mechanics

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2014

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Vol. 66, nr 1

19--35

EN

In this work different formulations of the boundary element method (BEM) in an analysis of materials with inclusions are presented. Models of composites in the form of linear-elastic solids containing rigid inclusions, elasto-plastic composites and piezomagnetic composites are considered. It is assumed that perfectly bonded matrix and inclusions are made of homogeneous materials. The developed computer codes are used to compute effective material properties by considering unit cells or representative volume elements (RVE). The influence of volume fractions of inclusions on overall properties of materials is studied.

4

Fast multipole boundary element method for the analysis of plates with many holes

Ptaszny J., Fedeliński P.

Archives of Mechanics

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2007

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Vol. 59, nr 4-5

385-401

EN

A three-node quadratic element version of the fast multipole boundary element method (FMBEM) for two-dimensional elastostatic problems is presented. The method is applied to the analysis of perforated plates. A comparison of convergence and accuracy of the present method using quadratic elements with the method using constant elements, presented by other authors, is given. Stress results for a square plate with a circular hole are investigated. Effective material properties of plates with many holes are estimated and compared to analytical results. Implementation of quadratic-element version of the FMBEM resulted in a lower number of degrees of freedom and expansion terms, and similar accuracy to constant-element version of the method, for the same structures. Influence of boundary conditions on the convergence of the iterative solver is investigated. The effectiveness of the FMBEM in relation to the conventional BEM is presented.