Indian Journal of

Engineering & Materials Sciences

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VOLUME 15

CODEN : IEMSEW

NUMBER 1

FEBRUARY 2008

ISSN : 0971-4588

 

CONTENTS

 

Engineering

 

 

Large deflection analysis of rhombic sandwich plates placed on elastic foundation

7

        Gora Chand Chell, Subrata Mondal & Goutam Bairagi

 

 

Determination of fracture parameters of concrete based on water-cement ratio

14

        Ragip Ince & Kürşat Esat Alyamaç

 

 

Effect of elevated temperatures and time on the compressive and tensile properties of concretes

23

        Şemsi Yazıcı & Gözde İnan Sezer

 

 

Dynamic permanent deformation testing of asphalt mixes and deformation waveform analysis

 

29

        Mesut Tigdemir

 

 

Effects of truck load position on longitudinal joint deterioration

36

        Muhammet Vefa Akpinar

 

 

Materials Science

 

 

High stress abrasive wear behaviour of shot peened AA2014 Al-alloy

41

        D P Mondal, E M Vinod, S Das & T S V C Rao

 

 

Synthesis of bismuth titanate (Bi4Ti3O12) powders via calcination of microwave-hydrothermally (MH) derived precursor

 

51

        Y B Khollam, S B Deshpande, V Samuel & H S Potdar

 

 

Synthesis and characterization of Mn0.4Zn0.6Al0.1Fe1.9O4 nano-ferrite for high frequency applications

 

55

Preeti Mathur, Atul Thakur & M Singh

 

 

Synthesis and characterization of Mn doped PZT ceramics

61

        K L Yadav & Pallavi Sharma

 

 

Properties of adhesive joint of inorganic nano-filler composite adhesive

68

        P K Ghosh & S K Nukala

 

 

  

Indian Journal of Engineering & Materials Sciences

Vol. 15, February 2008, pp. 7-13

 

 

 

Large deflection analysis of rhombic sandwich plates placed on elastic foundation

 

Gora Chand Chell, Subrata Mondal & Goutam Bairagi

 

This paper presents non-linear analysis of rhombic sandwich plates placed on elastic foundation under uniform load. Banerjee’s hypothesis1 involving a new form of energy expression in the total potential energy of the system has been employed. As a consequence the differential equation is decoupled keeping intact its non-linear character. The aim of the present study is to analyze the non-linear behaviour of rhombic sandwich plates placed on elastic foundation for different skew angles. The results have been obtained both for movable and immovable edges from a single cubic equation. Numerical results (central deflection versus load) have been computed and compared with known results (K=0) for square sandwich plates only. The corresponding linear analysis (K=0) is also presented. The results thus obtained are in good agreement with those repoted in the literature.

 

Indian Journal of Engineering & Materials Sciences

Vol. 15, February 2008, pp. 14-22

 

 

Determination of fracture parameters of concrete based on water-cement ratio

Ragip Ince & Kürşat Esat Alyamaç

 

The aim of this study is to predict formulas based on the Abrams’ Law between fracture parameters of concrete and w/c. Therefore, a series of three-point bend test on specimens were performed. The beams were made from mixes with water/cement ratios varying in the range of 0.34-0.85. The fracture parameters for each mix were calculated according to a popular fracture mechanics approach — two-parameter model. The present experimental data indicate that the fracture parameters of two-parameter model are inversely proportional to w/c ratios. In conclusion, the present test results are in agreement with the Abrams’ Law.

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 15, February 2008, pp. 23-28

 

 

Effect of elevated temperatures and time on compressive and tensile
properties of concretes

Şemsi Yazıcı & Gözde İnan Sezer

In this study, the effects of temperature level and time on the mechanical behaviour of concrete have been investigated. The concrete mixtures are produced using two different water/cement (w/c) ratios: 0.4, and 0.6. 288 cube (100 × 100 × 100 mm) specimens are prepared from these concrete mixtures and cured at 28 days. After standard curing period, specimens are dried in a furnace at 105°C for 4 h. Then the specimens are kept in loboratory for 1 day before exposing to 300, 600 and 900°C for 1, 3, and 5 h. Then compressive strength and split tensile strength are determined. It is concluded that, compressive strength and split tensile strength of the specimens are reduced after the high temperature exposure. Compressive strength losses of tested concretes are reduced with increasing w/c ratio. Remarkable effect is occurred in first 3 h in terms of strength losses.

 

Indian Journal of Engineering & Materials Sciences

Vol. 15, February 2008, pp. 29-35

 

 

Dynamic permanent deformation testing of asphalt mixes and deformation waveform analysis

Mesut Tigdemir

 

In this study, different specimens of hot mix asphalt (HMA) have been constructed in the laboratory and tested under repeated loading; first permanent deformation and later fatigue tests using Suleyman Demirel University Asphalt Tester equipment (SDU-Asphalt Tester). This study reports evaluation of available information about relationship between permanent deformation and fatigue cracking. Analysis of data shows that the fatigue life of the pavement may be modelled in terms of data obtained from repeated loading axial permanent deformation test results. Based on the analysis of the estimation model for fatigue life from permanent deformation testing, it is concluded that for the evaluation of HMA in fatigue characterization, repeated load axial test for permanent testing can be used in a very satisfactory manner. To be able to model the fatigue lives, in addition to conventional fatigue model parameters new parameters from repeated load permanent deformation test are taken into consideration. Hence, only by examining the permanent deformation tests, it may be possible to predict the fatigue lives of the specimens without carrying out time-consuming fatigue tests.

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 15, February 2008, pp. 36-40

 

 

Effects of truck load position on longitudinal joint deterioration

 

Muhammet Vefa Akpinar

 

Longitudinal joint cracks between asphalt mats are common problems in asphalt pavements and often deteriorate faster than other areas. The cracks resulting from the deteriorated longitudinal joints are very important for determining the performance life of the asphalt pavements. Cracks in the longitudinal joints allow the ingress of water into the pavement leading to further disintegration. In the urban areas asphalt paving is often done in stages to facilitate traffic control. In most widening projects, the lane marking does not coincide with the edge of the pavement. This results in traffic loads traveling at variable distance from the edge although the most common assumption in modern flexible pavement evaluation and design is that the wheel path is located about 50-100 cm from the edge of the pavement. It is suspected that the loading near the edge is one of the primary causes of longitudinal joint deterioration. In this study, mechanistic analysis with the finite element (FE) technique has been conducted to predict pavement response at the longitudinal joint under the truck load at different lateral positions relative to the joint. The FE analysis results showed that the position of the truck significantly affects the strains at the longitudinal. Tremendous increase in tensile strain was observed as the truck position nears the longitudinal joint. Maximum critical strains occur when the truck is positioned right at the longitudinal joint. The lane marking should be done in such a way that the right wheel path is located about 53 cm from the longitudinal joint.

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 15, February 2008, pp. h41-50

 

 

High stress abrasive wear behaviour of shot peened AA2014 Al-alloy

 

D P Mondal, E M Vinod, S Das & T S V C Rao

 

AA2014 Al alloy specimens (in the form of plates) have been shot peened to varying intensity levels (0.14 to 0.48 mm ALMEN ‘N’) and the effect of shot peening intensity on the subsurface plastic deformation, surface and subsurface residual stress field, depth of peening and microstructure evolution has been investigated. The influence of shot peening intensity on the high stress abrasive wear behaviour has also been investigated. The wear rate reduced significantly due to mild shot peening. Intensive shot peening did not lead to any significant improvement in wear resistance, rather beyond a critical peening intensity, the wear resistance of material starts deteriorating.

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 15, February 2008, pp. 51-54

 

 

Synthesis of bismuth titanate (Bi4Ti3O12) powders via calcination of
microwave-hydrothermally (MH) derived precursor

Y B Khollam, S B Deshpande, V Samuel & H S Potdar

 

Micrometer sized platelet-like particles of bismuth titanate (Bi4Ti3O12) are prepared successfully by the calcination of a mixed-precursor in air. The mixed precursor is precipitated under microwave-hydrothermal (MH) treatment via dissolution-recrystallization kinetics. The mixed precursor is precipitated in-situ by giving MH treatment (at 200°C, 200 psi, and 30 min hold time) to the hydrolysed slurry containing Bi and Ti cations. The slurry was prepared by adding 20% aqueous KOH precipitant solution to a well-mixed stoichiometric nitrate solution containing Bi and Ti cations. XRD results revealed that the as-dried precursor consisted of a homogeneous mixture of non-crystalline particles of Bi2O3 and TiO2. The calcination of the as-dried precursor at 700°C/2 h in air resulted in the formation of micron sized platelet like single-phase Bi4Ti3O12 powders having orthorhombic structure.

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 15, February 2008, pp. 55-60

 

Synthesis and characterization of Mn0.4Zn0.6Al0.1Fe1.9O4 nano-ferrite
for high frequency applications

 

Preeti Mathur, Atul Thakur & M Singh

 

Nano-ferrite of composition Mn0.4Zn0.6Al0.1Fe1.9O4 synthesized by co-precipitation method has been reported. The structural studies have been made by using X-ray diffraction (XRD) technique and scanning electron microscopy (SEM), which confirms the formation of single spinel phase and nanostructure. The dc resistivity is studied as a function of temperature and values are found about two times more than those for the samples prepared by the other chemical methods due to stoichiometric composition and better crystal structure of the ferrite. Even at nanolevel, the value of initial permeability is found to be 495 and low magnetic losses make these ferrites especially suitable for high frequency applications. The particle size is calculated using Scherrer’s equation for Lorentzian peak, which comes out between
32-43 nm. Possible mechanisms contributing to these processes have been discussed.

Indian Journal of Engineering & Materials Sciences

Vol. 15, February 2008, pp. 61-67

 

 

Synthesis and characterization of Mn doped PZT ceramics

 

K L Yadav & Pallavi Sharma

 

In the present work, the effect of Mn doped PZT ceramics with composition Pb(Zr­0.52­Ti0.48)O3 + x wt.% of Mn­O2, (where x =0, 1, 2 and 3) has been reported. The samples are prepared by employing a simple co-precipitation technique using nitrates of lead, zirconium and titanium isopropoxide. X-ray diffraction studies confirm the formation of pure phase and homogeneous ceramics of tetragonal symmetry. Scanning electron micrographs shows a uniform grain distribution and the grain size and shape are modified upon Mn addition. Increase in Mn content causes a decrease in average grain size of the material. Dielectric measurements demonstrate a decrease in the dielectric constant and increase in dielectric loss with increase in Mn. The dielectric dispersion is large for the higher concentration of Mn ions in PZT at lower frequencies and is attributed to the space charge accumulation. The undoped and Mn doped PZT ceramics exhibit the hysteresis loops which confirms the ferroelectric behaviour. The prepared ceramics have very low dielectric loss, high dielectric constant and high transition temperature which may be useful for device application.

 

 

 

Indian Journal of Engineering & Materials Sciences

Vol. 15, February 2008, pp. 68-74

 

 

Properties of adhesive joint of inorganic nano-filler composite adhesive

 

P K Ghosh & S K Nukala

 

The characteristics of adhesive joints of aluminium sheet containing epoxy based composite adhesives containing nano-filler of ZrO2 powder have been studied. The composite adhesives containing 10, 15 and 20wt.% of about 20±3 nm size ZrO2 powder are applied to mechanically treated aluminium substrates. The single lap joints of the composite adhesive are characterized by their tensile lap shear strength as a function of the bond-line thickness as well as the amount of filler. The characteristics of the composite adhesive joint have been compared to those of the conventional epoxy adhesive joints. The bond-line thickness of the adhesive with respect to the amount of the ZrO2 nano-filler has been optimised for maximum tensile single lap shear strength of the adhesive joint of mechanically treated aluminium substrate. In comparison to conventional epoxy adhesive joints, the nano-filler epoxy based adhesive joint of aluminium shows significantly improved lap shear strength as a function of bond line thickness of adhesive and amount of filler in it.