NISCAIR Online Periodicals Repository Collection: IJEMS Vol.11(2) [April 2004]

A simple method to evaluate the critical loads of cantilever columns with follower forces

Mon, 29 Mar 2004 22:58:59 GMT

Title: A simple method to evaluate the critical loads of cantilever columns with follower forces

Authors: Raju, K Kanaka; Rao, G Venkateswara

Abstract: A simple method, based on two term Galerkin method, is presented here to evaluate the critical loads of a uniform cantilever column with follower forces. Three types of follower forces are considered. If two terms are used in the Galerkin method, a quadratic equation for the frequency is obtained and the critical loads are evaluated by making the radical of the solution of the quadratic equation zero, avoiding a frequency mapping with the applied follower force. When the radical is zero, the value of the frequency obtained is the coalescence frequency. The accuracy of results obtained from the present method is quite suitable for engineering purposes. The accuracy can further be improved if suitable admissible functions, which represent the first two modes of vibration accurately, are chosen.

Page(s): 143-146

Experimental investigation on the supersonic jet impingement

Mon, 29 Mar 2004 22:58:59 GMT

Title: Experimental investigation on the supersonic jet impingement

Authors: Ghanegaonkar, P M; Ramanujachari, V; Vijaykant, S

Abstract: In order to understand the effects of supersonic jet impingement, static tests are conducted in a small-scale rocket motor loaded with a typical nitramine propellant to produce a nozzle exit Mach number of 3. This jet is made to impinge on a plate aligned vertically to the nozzle axis. The distance between the nozzle exit and the plate is varied from 2 to 6 times the nozzle exit diameter. The pressure rise due to jet impingement on the plate has been measured using pressure transducers located at ten different radial locations. The pressure - time data are analyzed to get an insight into the flow field upstream of the plate. The maximum pressure exerted on the plate is about 20-30% of the maximum pressure generated in the combustion chamber. Ten static tests are carried out to obtain the effects of nozzle divergence angle, axial distance between the nozzle exit and the plate and the chamber stagnation pressure on the flow field.

Page(s): 100-106

Thermoluminescence response of some common brands of iodised salt

Mon, 29 Mar 2004 22:58:59 GMT

Title: Thermoluminescence response of some common brands of iodised salt

Authors: Gartia, R K; Sharma, B Arunkumar; Ranita, Usham

Abstract: Thermoluminescence (TL) response of ten Indian brands of iodized salt has been recorded for possible use in TL dosimetry. It has been observed that a heat treatment of one minute at 500°C reduces the complexity of the glow curve pattern. Further, in many cases heat treated samples exhibit intense peaks at higher temperature which are stable at room temperature (25°C) whereas some brands like Sungold, Tata, Ankur and Dandi inhibit such peaks. TL response of two such cases namely the integration zone 200-400°C of the glow curve of Taja and Shudh brands of iodized salt follow polynomial of degree three to beta exposure in the dose range 1 to ~ 25 Gy; indicating its potentiality in TL dosimetry.

Page(s): 137-142

Loss factor for a clamped edge circular plate subjected to an eccentric loading

Mon, 29 Mar 2004 22:58:59 GMT

Title: Loss factor for a clamped edge circular plate subjected to an eccentric loading

Authors: Gupta, M K; Nigam, S P

Abstract: Present article deals with the analytical evaluation of modal loss factor of a clamped edge thin circular plate of uniform thickness subjected to an eccentric harmonic point load. Starting with the fundamental equation of forced transverse vibration of a thin elastic plate in terms of Green’s function; the expression for the deflections is determined. Stresses are calculated with the help of general stress-deflection equations and the modal loss factor is evaluated at resonance condition. The nodal circles’ radii are also determined analytically for each mode shape.

Page(s): 79-84