Begell House Inc.
Composites: Mechanics, Computations, Applications: An International Journal
CMCA
2152-2057
1
4
2010
PROCEDURES TO BUILD PLATE MICROMECHANICAL MODELS FOR COMPOSITES LIKE PERIODIC BRICKWORKS: A CRITICAL REVIEW
287-313
10.1615/CompMechComputApplIntJ.v1.i4.10
Antonella
Cecchi
Department of Architecture Construction Conservation (DACC), University IUAV of Venice, Dorsoduro 2206, Venice, 30123, Venice, Italy
periodic brickwork
Love–Kirchhoff plate
Mindlin–Reissner plate
asymptotic homogenization
equivalent compatible method
Procedures for constructing plate models to describe the out-of-plane mechanical behavior of regular brickwork are proposed. Both asymptotic homogenization procedures and direct identification procedures — methods based on balance by internal work in the discrete model and in the continuous model for a class of regular motions — have been proposed to obtain relations between the 3D discrete model and the 2D plate continuum model. A crucial problem, with the choice of identification procedures, is how kinematic, dynamic, and constitutive prescriptions of a discrete system are transferred to the continuous one. Hence, constitutive functions of the plate may be different. A Love−Kirchhoff plate model based on standard homogenization, for linear elastic periodic brickwork, has been already proposed by Cecchi and Sab (2002b). This model has been also developed in the case both of infinitely rigid blocks and of elastic blocks connected by elastic interfaces taking into account shear effects leading to the identification of a new Mindlin−Reissner homogenized plate model (Cecchi and Sab, 2004, 2006). In this case, the identification between the 3D block discrete model and the 2D plate continuum model is based on a relation at the order 1 in the displacement and at the order 0 in the rotation. The Mindlin−Reissner model when blocks are rigid blocks based on a compatible identification at the order 1 both in the displacement and in the rotation has been performed by Cecchi and Rizzi (2003, 2005). Here these models have been implemented also in the case of elastic blocks. The idea is to critically analyze the accuracy of these identification models by comparison with a 3D F.E. model for some meaningful case.
MODELING OF DEGRADATION OF THE COMPOSITE PROPERTIES ON CRACKING AND DELAMINATION WHEN SUBJECTED TO STATIC AND CYCLIC LOADING
315-331
10.1615/CompMechComputApplIntJ.v1.i4.20
Doan Chuck
Luat
Moscow Aviation Institute (Technical University), Moscow, Russia
Sergey A.
Lurie
Moscow Aviation Institute, Moscow, Russia; Institute of Applied Mechanics of Russian Academy of Science, Moscow, Russia;Lomonosov Moscow State University, Russia
A. A.
Dudchenko
Moscow Aviation Institute (National Research University), 4 Volokolamskoe Shosse, Moscow, 125993, Russia
layered composites
accumulation of damages
degradation of properties
transversal cracking
delamenation
The model of damage accumulation and the model of degradation of the mechanical properties of layered composites due to the defects of the type of transversal cracking and interlayer cracks have been developed. An analysis of the increase in the defectiveness is made, and the model of degradation of properties is suggested. An algorithm of the refinement of the stress-strain state with account for the increase in the defectiveness is presented; its implementation is possible with the use of the finite-element method.
THE ALGORITHM OF SEARCHING FOR CONSTANTS IN A MODEL OF THE MECHANICAL BEHAVIOR OF RUBBER
333-351
10.1615/CompMechComputApplIntJ.v1.i4.30
A. G.
Pelevin
Institute of Continuum Mechanics, Ural Branch of the Russian Academy of Sciences, Perm, Russia
A. L.
Svistkov
Institute of Continuous Media Mechanics, Ural Branch of the Russian Academy
of Sciences, 1 Academician Korolev Ave., Perm, 614000, Russian Federation
A. A.
Adamov
Institute of Continuum Mechanics, Ural Branch of the Russian Academy of Sciences, Perm
Lauke
Bernd
Leibniz Institut für Polymerforschung, Dresden e.V., Dresden, Germany
Heinrich
Gert
Leibniz Institut für Polymerforschung, Dresden e.V., Dresden, Germany
governing equations
finite deformations
viscoelasticity
softening
model
rubber
A model of the mechanical behavior of rubber is considered. For constructing the governing equation, a scheme whose points are connected by elastic, viscous, plastic, and transmission elements is used. To describe the properties of each of the elements, the well-known equations of the nonlinear theory of elasticity, of the theory of nonlinear viscous fluids, and of the theory of plastic flow of a material under the conditions of the finite deformations of a medium are employed. An algorithm for obtaining the constants of the model is suggested. The search for these constants is arranged in steps. The constants in the governing equations determined at the previous step do not change at subsequent ones. The experiments (cyclic loadings with relaxation and creep) allow one to obtain more information on the viscoelastic properties of rubber.
ANALYSIS OF JUTE FIBER-REINFORCED EPOXY/VAc-EHA/HMMM IPN COMPOSITE PLATE
353-360
10.1615/CompMechComputApplIntJ.v1.i4.40
Raghvendra Kumar
Misra
School of Mechanical Engineering, Gautam Buddha University, Greater Noida, Gautam Buddha Nagar, Uttar Pradesh-201308, India
Chandan
Datta
Department of Polymer Engineering, Birla Institute of Technology, Mesra, Ranchi-835215, India
jute fiber
epoxy
vinylacetate-2-ethylhexylacrylate
full-IPN
semi-IPN
Jute fiber-reinforced semi-IPN and full-IPN Epoxy/VAc-EHA/HMMM IPN composite plates have been prepared in a laboratory at different volume fractions of VAc-EHA for the evaluation of mechanical properties. An epoxy solution was blended with VinylAcetate-2-Ethylhexylacrylate (VAc-EHA) resin in an aqueous medium at varying weight fractions of VAc-EHA. It has been observed that as soon as the percentage of the VAc-EHA increases, the ultimate tensile strength and modulus of elasticity of a jute fiber-reinforced semi-IPN and full-IPN composite plate decreases. A jute fiber-reinforced full-IPN composite plate is compact and harder than a jute fiber-reinforced semi-IPN composite plate.
STUDY OF ELASTIC AND STRENGTH PROPERTIES OF HYBRID AND GRADIENT POLYMER COMPOSITES
361-373
10.1615/CompMechComputApplIntJ.v1.i4.50
A. M.
Kuperman
N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
R. A.
Turusov
N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
A. Ya.
Gorenberg
N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, Moscow, Russia
hybrid and gradient polymer composites
elastic and strength properties
The paper deals with the properties of hybrid (HPC) and gradient (GPC) polymer composites depending on the ratio of the content of different fibers. The major factor governing the regularities of the mechanical behavior of composites is the ratio of ultimate strains of reinforcing fibers. Synergy effects of increasing deformability of carbon fibers under tension and organic fibers under compression in a glass-fiber-reinforced (GFR) matrix are observed. Gradient materials with a nonuniform structure enable one to assign a law of variation of the material stiffness, which gives an optimal stress distribution in a whole product under loading.