P. Alagusundaramoorthy

Bio: P. Alagusundaramoorthy is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Flexural strength & Sandwich-structured composite. The author has an hindex of 12, co-authored 33 publications receiving 437 citations. Previous affiliations of P. Alagusundaramoorthy include University of Kentucky.

Flexural Behavior of Concrete Sandwich Panels Under Punching Load and Four-Point Bending—Experimental and Analytical Study

Abstract: Concrete sandwich structural panels can serve dual purposes of transferring load and insulating. This paper presents and discusses results of experimental and numerical studies carried out to understand the flexural behavior of concrete sandwich panels under different flexural loading conditions such as four-point bending and punching load. The experimental study consisted of testing two prototype concrete sandwich panels. Wythes of the panels were reinforced using wire mesh and rebars, and shear connectors were used to connect both wythes. Experimental study indicated that flexural behavior of these panels is significantly affected by type of the loading conditions. Though constructional details of both panels tested in this study are same, failure mode of the panels are different under four-point bending and punching load. The panel tested under four-point bending failed by forming inclined shear cracks and the panel tested under punching load failed by forming flexural cracks. Numerical analysis was carried out using finite element package ABAQUS. Numerical models developed are able to approximately predict load-deflection responses of concrete sandwich panels under different loading conditions. Further experimental and numerical studies are required in this area toward developing design guidelines.

Experimental and analytical investigations on the failure modes of concrete sandwich panels under axial compression

Abstract: Abstract In this paper, precast lightweight Concrete Sandwich Panels (CSP) with reinforced concrete skins/wythes, truss shear connectors and expanded polystyrene core are proposed to be a good alternative for replacing conventional load bearing brick masonry walls. Literature review indicated that studies examining the failure modes of concrete sandwich panels under axial compression are not reported. Towards filling this gap and for developing design guidelines for practical applications, in this paper, failure modes of CSP are theoretically defined. Experimental investigations are conducted to determine the actual failure modes, strength and behaviour of the panels under axial compression. The failure modes observed from the experimental study are compared with the theoretical failure modes. Test results indicated that CSP can be used for practical applications as an alternative to conventional brick masonry walls. Attempts are also made to find the applicability of available strength predicting formulas of sandwich members/RC walls for concrete sandwich panels. Results showed that the available formulas have to be modified for predicting the axial compressive strength of CSP with reasonable accuracy.

Ultimate Strength of Steel and Glass Fibre Reinforced Composite Plates With Square Opening Under Axial and Out of Plane Loads

Abstract: The weight of glass fiber reinforced polymer composite (GFRP) plate is about one fourth of the steel plate and can be used in ship and offshore structures, so that the payload can be increased. However comparative studies on the behaviour of steel and GFRP composite plates with square opening have not been studied in detail. The experimental studies on steel and GFRP plates with and without openings are carried out for the combined loading of axial compression and out-of-plane loads. The in-plane and out-of-plane deflections are measured. The reduction in the axial load carrying capacity of the plates due to out-of-plane load is quantified. The effect of column slenderness ratio and plate slenderness ratio on the collapse load of simply supported stiffened plates is presented. Two sets of interaction equations are developed, one for the steel plate and another for the GFRP composite plate.Copyright © 2010 by ASME

Stability of stiffened plates with initial imperfections

Abstract: An experimental study of the effect of plate slenderness ratio and column slenderness ratio on the collapse load of simply supported stiffened plates with initial imperfections, loaded in compression, is presented. A generalized computer program for the semiempirical solutions based on the strut approach and the orthotropic plate approach is developed. A finite element analysis program based on the orthotropic plate approach is developed and a new collapse criterion is introduced. The analytical calculations are compared with the experimental results and uncertainty parameters are calculated. The effect of initial geometric imperfections, plate slenderness ratios, and column slenderness ratios on the collapse load of stiffened plates is studied. A set of conclusions is drawn based on the experimental and analytical studies carried out.

Fiber-Reinforced Polymer Composites: Manufacturing, Properties, and Applications.

Abstract: Composites have been found to be the most promising and discerning material available in this century. Presently, composites reinforced with fibers of synthetic or natural materials are gaining more importance as demands for lightweight materials with high strength for specific applications are growing in the market. Fiber-reinforced polymer composite offers not only high strength to weight ratio, but also reveals exceptional properties such as high durability; stiffness; damping property; flexural strength; and resistance to corrosion, wear, impact, and fire. These wide ranges of diverse features have led composite materials to find applications in mechanical, construction, aerospace, automobile, biomedical, marine, and many other manufacturing industries. Performance of composite materials predominantly depends on their constituent elements and manufacturing techniques, therefore, functional properties of various fibers available worldwide, their classifications, and the manufacturing techniques used to fabricate the composite materials need to be studied in order to figure out the optimized characteristic of the material for the desired application. An overview of a diverse range of fibers, their properties, functionality, classification, and various fiber composite manufacturing techniques is presented to discover the optimized fiber-reinforced composite material for significant applications. Their exceptional performance in the numerous fields of applications have made fiber-reinforced composite materials a promising alternative over solitary metals or alloys.

A critical review of retrofitting methods for unreinforced masonry structures

Abstract: Unreinforced masonry (URM) buildings are common throughout Latin America, the Himalayan region, Eastern Europe, Indian subcontinent and other parts of Asia. It has been observed that these buildings cannot withstand the lateral loads imposed by an earthquake and often fails, in a brittle manner. Methods for retrofitting URM buildings to increase the time required for collapse and also to improve the overall strength widely vary. This review has collated information on various types of retrofitting methods either under research or early implementation. Furthermore, these methods are categorized and critically analyzed to help further understand which methods are most suitable for future research or application in developing countries. The comparison of the different methods is based on economy, sustainability and buildability and provides a useful insight. The study may provide useful guidance to policy makers, planners, designers, architects and engineers in choosing a suitable retrofitting methodology.

Effects of Ratio of CFRP Plate Length to Shear Span and End Anchorage on Flexural Behavior of SCC RC Beams

Abstract: The aim of this experimental investigation is to study the effect of the ratio of carbon fiber-reinforced polymer (CFRP) precured laminate length to shear span and different end plate anchorage systems on the flexural behavior of reinforced concrete (RC) beams cast with self-consolidating concrete (SCC). SCC with a grade of 54 MPa has been used throughout this research to ensure consistent high quality and high concrete compressive strength in all beams and to eliminate the need of any compaction. Ten RC beams strengthened with CFRP plate lengths to shear span ratio of 0, 25, 70, and 85% with and without end anchorages, were tested under monotonic loading. In particular, a single layer of U-wrap sheet and two layers of U-wrap sheets with one layer in the longitudinal direction and the other in the transverse direction were used as end anchorages (double wrap). The results were compared with each other and with those of the same test conducted on an unstrengthened control beam specimen. The load-deflection...

Evaluation of sandwich panels with various polyurethane foam-cores and ribs

Abstract: The objective of this study was to evaluate three potential core alternatives for glass fiber reinforced polymer (GFRP) foam-core sandwich panels. The proposed system could reduce the initial production costs and the manufacturing difficulties while improving the system performance. Three different polyurethane foam configurations were considered for the inner core, and the most suitable system was recommended for further prototyping. These configurations consisted of high-density polyurethane foam (Type 1), a bidirectional gridwork of thin, interconnecting, GFRP webs that is in-filled with lowdensity polyurethane foam (Type 2), and trapezoidal-shaped, low-density polyurethane foam utilizing GFRP web layers (Type 3). The facings of the three cores consisted of three plies of bidirectional E-glass woven fabric within a compatible polyurethane resin. Several types of small-scale experimental investigations were conducted. The results from this study indicated that the Types 1 and 2 cores were very weak and flexible making their implementation in bridge deck panels less practical. The Type 3 core possessed a higher strength and stiffness than the other two types. Therefore, this type is recommended for the proposed sandwich system to serve as a candidate for further development. Additionally, a finite element model (FEM) was developed using software package ABAQUS for the Type 3 system to further investigate its structural behavior. This model was successfully compared to experimental data indicating its suitability for parametric analysis of panels and their design.