Begell House Inc.
Composites: Mechanics, Computations, Applications: An International Journal
CMCA
2152-2057
2
3
2011
SIMULATION OF RHEONOMIC PROPERTIES OF SHAPE MEMORY ALLOYS
171-185
10.1615/CompMechComputApplIntJ.v2.i3.10
A. A.
Movchan
Federal Governmental Budgetary Scientific Institution "Institute of Applied Mechanics," Russian Academy of Sciences, Moscow, Russia
K. Yu.
Klimov
Moscow State University, Moscow, Russian Federation
shape memory alloys
rheonomic properties
martensite inelasticity
superelasticity
stress relaxation
model
The reasons of unique thermomechanical properties of shape memory alloys (SMA) are thermoelastic phase and structural transformations that are diffusionless processes; therefore, SMA properties are, normally, interpreted and simulated as scleronomous. However, the recent experimental data indicate that SMA properties are not completely scleronomous. This article proposes a very simple model for description of rheonomic properties of SMA. The time-dependent behavior of SMA in rigid and soft loading, stress relaxation and stepwise loading under the conditions of martensite inelasticity and superelasticity is described. It was found that modeling results comply well with experimental data.
THERMOMECHANICAL PROPERTIES OF DIAMOND-FILLED COMPOSITES FORMED IN A CONSTANT MAGNETIC FIELD
187-193
10.1615/CompMechComputApplIntJ.v2.i3.20
N. I.
Shut
M. P. Dragomanov National Pedagogical University, Kiev
P. M.
Malezhik
M. P. Dragomanov National Pedagogical University, Kiev
thermomechanical properties
epoxy composites
chemical modification
magnetic field
The investigations of the thermomechanical properties of nanocomposites on the basis on the ED-20 epoxy oligomer, filled with ultrafine diamond and amino diamond derived from the former, generated in a constant magnetic field, showed that the use of a modified diamond as an epoxy polymer filler with amino groups in the surface layer improves properties of filled composites. It was demonstrated that the effect of a constant magnetic field manifests itself in a decrease of relative deformation at the same degrees of filling of all compositions studied.
ANALYSIS OF A SHORT BANANA FIBER-REINFORCED HDPE/POLY (∈-CAPROLACTONE) SKEW COMPOSITE PLATE USING THE MULTIQUADRIC RADIAL BASIS FUNCTION METHOD
195-221
10.1615/CompMechComputApplIntJ.v2.i3.30
Raghvendra Kumar
Misra
School of Mechanical Engineering, Gautam Buddha University, Greater Noida, Gautam Buddha Nagar, Uttar Pradesh-201308, India
P. C.
Mishra
School of Mechanical Engineering, KIIT University, Bhubaneswar, Orissa 751024, India
Sandeep
Kumar
Defence Materials and Stores Research and Development Establishment, Kanpur, India
banana fibers
skew angle
multiquadric radial basis function
stiffness
rectangular
square
Short banana fiber-reinforced high-density polyethylene/poly (∈-caprolactone) skew composite plates have been prepared in the laboratory at different volume fractions of the fibers to determine the mechanical properties. Short cellulose-rich (>65%) banana fibers are treated by sodium hydroxide to increase its adhesiveness with the matrix. The effect of skew angle is observed in simple supported and clamped edge square and rectangular short banana fiber-reinforced high-density polyethylene/poly (∈-caprolactone) skew composite plates. The mechanical behavior of a square banana fiber-reinforced skew composite plate is different as compared to a rectangular banana fiber-reinforced skew composite plate. In order to study the static and dynamic response of a short banana fiber-reinforced skew composite plate at a uniformly distributed load, a multi-quadric radial basis function (MQRBF) method is applied. The skew angle and percentage of short banana fibers define the stiffness and damping behavior of a banana fiber-reinforced skew composite plate.
IMPACT OF PRELIMINARY CYCLIC LOADING AND TEMPERATURE ON RESIDUAL STRENGTH OF UNIDIRECTIONAL COMPOSITES
223-232
10.1615/CompMechComputApplIntJ.v2.i3.40
A. V.
Babushkin
State National Technical University of Perm, Perm, Russian Federation
A. V.
Kozlova
State National Technical University of Perm, Perm, Russian Federation
unidirectional fiberglass and organoplastics
residual properties of damaged structures
experimental functions of the damage
dependences of polymeric composite material properties on temperature
This research included tests of the cyclic strength and durability as well as of the residual strength of fiberglass and organoplastic samples at normal and elevated temperatures. Mechanisms of destruction of unidirectional fibrous plastics are analyzed at cyclic and static loading of ring samples using the so-called NOL method. Experimental dependences of the residual strength on the preliminary cyclic load intensity are obtained, and experimental functions of the damage for investigated materials at room and increases temperatures are built.
FRACTURE MODEL OF PIECEWISE HOMOGENOUS MEDIUM IN EXFOLIATION OF ELASTO-PLASTIC STRUCTURED MATERIALS
233-246
10.1615/CompMechComputApplIntJ.v2.i3.50
V. M.
Kornev
M. A. Lavrentiev Institute of Hydrodynamics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russian Federation
N. S.
Astapov
M. A. Lavrentiev Institute of Hydrodynamics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russian Federation
fracture criteria
stress intensity factors
crack opening
diagrams of quasi-brittle fracture
Propagation of a crack located on the interface of media in a piecewise homogenous structured material is considered. Under tension applied at infinity, the mode I fracture is realized. The case when elastic characteristics of materials coincide and strength ones differ greatly is analyzed in detail. The description of construction of diagrams for quasi-brittle fracture is given for a plane stressed state.
INFLUENCE OF THE ARCHITECTURE AND ELEMENTAL-CHEMICAL COMPOSITION ON THE STRUCTURE AND PROPERTIES OF CARBONACEOUS COMPOSITE MATERIALS
247-270
10.1615/CompMechComputApplIntJ.v2.i3.60
V. S.
Terentieva
Moscow Aviation Institute (State Technical University), Moscow, Russian Federation
I. O.
Leipunskii
Institute for Energy Problems of Chemical Physics, Russian Academy of Sciences, Moscow, Russian Federation
A. I.
Eremina
Moscow Aviation Institute (State Technical University), Moscow, Russian Federation
P. A.
Pshechenkov
Institute for Energy Problems of Chemical Physics, Russian Academy of Sciences, Moscow, Russian Federation
A. N.
Astapov
Moscow Aviation Institute (National Research University), 4 Volokolamskoe
Highway, Moscow, 125080, Russia
carbonaceous composite material
"Gravimol
" thermally stressed element of the construction
porosity
microcracks
oxidation resistance
high-enthalpy flow
protective coating
oxide film
surface properties
The results of a critical analysis of the state-of-the art in the area of the development and prospects of development of different kinds of heat-resistant carbonaceous composite materials (CCM), complex investigation of their structure and oxidation resistance are presented. Attention is focused on home-made CCMs with the aim of selecting a structural material for the parts and units of flying vehicles and new-generation propulsion systems operating in hypersonic flows of oxygen-containing plasma under simultaneously acting nonstationary mechanical and thermal loadings. The results of investigation of the oxidation resistance of the best of CCMs that demonstrated a complete loss of protective properties and the burning-out of the material at Tw > 1300°C even under the conditions of natural convection of air are presented. The necessity of introducing an additional layer with a more effective protective ability into the composition of the wall is shown. The possibilities of improving the service properties of the carrier material with the aid of high-temperature multifunctional coatings, being developed, are considered. The results of the work can be used in developing and designing thermally stressed elements of the structures of aerospace and rocket hardware.