Conference Papers

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    Blast vibration signal analysis using S-transform
    (Institute of Electrical and Electronics Engineers Inc., 2016) Teja, V.V.S.A.; Chaitanya, S.V.; Akula, U.; Srihari, P.; Sastry, V.R.
    Rock blasting in mines and quarries is an important operation meant for fragmenting and displacing the hard rock mass / strata. The unavoidable environmental effect is the ground vibration, resulting from the wastage of explosive energy. Ground vibrations travelling to far off distances may have effect on the structures. Signal processing techniques play a vital role in analyzing the velocity of ground vibration signals in rock blasting. So far, time-frequency domain is being used for analyzing the ground vibration signals. However, usage of S-Transform, we get frequency dependent resolution of time-frequency domain. It is possible to simultaneously analyze the signal using time, frequency and amplitude values obtained by applying S-transform. A case study is presented in this paper, wherein the S-Transform is applied to the ground vibration velocity signals, which helps in better understanding and analysis of the signal compared to Fourier transform and Wavelet transform techniques. © 2016 IEEE.
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    Frequency and deflection analysis of cenosphere/glass fiber interply hybrid composite cantilever beam
    (American Institute of Physics Inc. subs@aip.org, 2018) Bharath, J.; Joladarashi, S.; Biradar, S.; Kumar, P.N.
    Interply hybrid laminates contain plies made of two or more different composite systems. Hybrid composites have unique features that can be used to meet specified design requirements in a more cost-effective way than nonhybrid composites. They offer many advantages over conventional composites including balanced strength and stiffness, enhanced bending and membrane mechanical properties, balanced thermal distortion stability, improved fatigue/impact resistance, improved fracture toughness and crack arresting properties, reduced weight and cost. In this paper an interply hybrid laminate composite containing Cenosphere reinforced polymer composite core and glass fiber reinforced polymer composite skin is analysied and effect of volume fraction of filler on frequency and load v/s deflection of hybrid composite are studied. Cenosphere reinforced polymer composite has increased specific strength, specific stiffness, specific density, savings in cost and weight. Glass fiber reinforced polymer composite has higher torsional rigidity when compared to metals. These laminate composites are fabricated to meet several structural applications and hence there is a need to study their vibration and deflection properties. Experimental investigation starts with fabrication of interply hybrid composite with cores of cenosphere reinforced epoxy composite volume fractions of CE 15, CE 25, CE15-UC as per ASTM E756-05C, and glasss fiber reinforced epoxy skin, cast product of required dimension by selecting glass fibre of proper thickness which is currently 0.25mm E-glass bidirectional woven glass fabric having density 2500kg/m3, in standard from cast parts of size 230mmX230mmX5mm in an Aluminum mould. Modal analysis of cantilever beam is performed to study the variation of natural frequency with strain gauge and the commercially available Lab-VIEW software and deflection in each of the cases by optical Laser Displacement Measurement Sensor to perform Load versus Deflection Analysis. Young's Modulus values obtained from deflection equation of cantilever beam with different respective load versus deflection values are compared and validated with value obtained using first mode of natural frequency equation of cantilever beam. © 2018 Author(s).