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Analysis of Anchorage Zone by Finite Element Method
on Windows Nt Cluster
-- P K Gupta and R N Khapre
This paper presents an application of cluster computing in finite element programming. A
cluster of eight PCs of different configurations
was developed and used in the present work. Three parallel solvers of
Gauss-Seidel Method (GSM), Gauss Elimination
Method (GEM) and Matrix Inversion Method (MIM) were developed
and implemented on this cluster to achieve a reduction in
the computational time in getting the solution of a
system of linear equations. The performances of these solvers
were compared and the most suitable solver was
implemented in a finite element software developed on Windows NT platform to analyze
the structural components. A typical problem of stress
analysis in the anchorage zone in a prestressed, post-tensioned concrete beam
was analyzed using a developed software on the developed
cluster and the variation in different components of
computational time was obtained. By computing speedup and
efficiency, the performance of the developed software
was presented. It was found in the present study that
the optimum number of computers required to form the cluster
varied between three and five. It was also observed that
an excessive increase in the number of computers resulted in
an increase in the total time due to increase in communication time.
© 2009 IUP. All Rights Reserved.
Boundary Element Analysis
of Elastic Line Inclusions
-- Mohammed Ameen
Modeling of elastic line inclusions in an elastic continuum of finite extent using the boundary element
method is addressed in this paper. In the literature, such elastic line inclusions are generally replaced by rigid
inclusions in order to reduce the complexity of the problem. The paper presents a boundary integral formulation
in which the elasticity of the line inclusion is accurately modeled. The elastic continuum is discretized using
the boundary element method, whereas the line inhomogeneity is modeled using linear and quadratic
interpolation elements. Numerical results are presented in comparison with analytical and finite element solutions
to demonstrate the accuracy of the developed method.
© 2009 IUP. All Rights Reserved.
Efficacy of Base Isolation for Seismic Safety
of URM Infills in RC Frame Buildings
-- Yogendra Singh, Samik Chakraborty and Ratnesh Kumar
In India, Unreinforced Masonry (URM) infills are invariably used in frame buildings for their low cost, ease
in construction, and good sound and heat insulation properties. However, safety of these infills during
earthquake is a major issue, particularly in important buildings like hospitals. Infills are subjected to in-plane forces
due to inter-storey drift and out-of-plane forces due to floor acceleration. Base isolation is a very
promising technique, which controls the inter-storey drift and floor accelerations, simultaneously. The present
study explores the efficacy of base isolation for achieving the desired seismic performance of URM infills. A
procedure is presented for the design of base isolation systems for URM infilled frame buildings. The efficacy of
base isolation is studied for two URM infilled RC (Reinforced Concrete) frame hospital buildings, four and
eight-storeys tall. The effect of isolators on dynamic characteristics, seismic performance, inter-storey drift
ratio and peak floor acceleration is presented. It is found that it is possible to design a viable isolation system
to achieve immediate occupancy performance level of URM infills in the four-storey building; however, only
life safety performance level could be achieved for the eight-storey building.
© 2009 IUP. All Rights Reserved.
Free and Forced Vibration Interactive
Analysis of a Framed Structure Under
Varying Soil Medium
-- Kumar Venkatesh, Y K Gupta and Alok Athaley
The interactive dynamic response of the framed structure significantly depends on the type of soil medium
and its properties. The dynamic interrelationship between the response of a structure and the characteristic of
soil medium is termed as the interaction effect. The finite element method has been employed to estimate the
effect of soil media on the dynamic response of framed structure, including the interaction effect.
A six-storey framed structure with raft foundation and soil medium has been considered as a system. The
soil continuum and raft foundation have been discretized using four-noded isoparametric elements, and
the superstructure by two-noded beam elements. The free vibration interaction analysis on this system
estimated the natural frequency and modal behavior of the system under various types of soils. The forced
vibration interaction analysis has been performed to estimate the interaction effect on the dynamic response of
the structure in terms of stress and strain. The property of soil medium has been varied by varying
Young's modulus and constant Poisson's ratio, while the other conditions have been achieved by varying Poisson's
ratio and constant Young's modulus. It has been observed from the compared dynamic interactive and
non-interactive analysis that varying soil medium significantly affects the natural frequency and mode shapes of the
framed structure. The variation of natural frequency is in the range of 20-30%. In the interactive case,
additional mode shapes are induced due to additional degree of freedom, compared to non-interactive case. The
varying soil properties have also affected the interactive static and dynamic stresses of the system at the junction
of foundation-soil medium significantly, compared to the structure-foundation interface.
© 2009 IUP. All Rights Reserved.
Structural Properties of Polypropylene Fiber
Reinforced Concrete
-- K Saravana Raja Mohan, P Jayabalan and A Rajaraman
Using fly ash as a partial substitute for cement in concrete construction has become popular mainly
because of its easy availability and economy in large volume construction. But the resulting deficiency in
performance of the concrete has been a cause for concern. This study proposes the introduction of polypropylene
fibers adaptively to compensate for strength. A series of experimental programs were carried out with fly ash,
fiber content, and layers as parameters. The fly ash content varied from 0-30% and fiber content from
0-0.60%. From the studies, it was found that the loss due to the introduction of fly ash could be easily
compensated through fibers. This study was carried out to investigate the feasibility of polypropylene fiber usage and
the effect of fiber length and content on the structural properties of this composite.
© 2009 IUP. All Rights Reserved.
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