http://nopr.niscpr.res.in/handle/123456789/8818 Fri, 09 Oct 2026 07:58:32 GMT 2026-10-09T07:58:32Z http://nopr.niscpr.res.in/handle/123456789/14098 Title: Reverse engineering of a hot ring compression test using FEM Authors: Pathak, K K; Kotwal, C P; Narayan, S P; Ramakrishnan, N Abstract: This study is related to reverse engineering solution of friction and yield stress in a hot ring compression test using finite element method (FEM). Ring material is steel and test temperature is 800°C. Load deflection curve and the deformed geometry, obtained from the test, are considered as the benchmark parameters for the reverse engineering. The numerical experimentation has been carried out in an iterative manner. The values of friction are varied to find the final geometry matching with the actual deformed shape. Having established the friction, yields stress is varied to match the tonnage employed in the test. It is observed that FEM can be very helpful in such kind of reverse engineering problems. Page(s): 189-192 Tue, 01 Jun 2004 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/14098 2004-06-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/9284 Title: Design and fabrication of few devices for dynamic measurement of magneto-electric effect Authors: Bhattacharya, G S; Mazumder, S; Baisnab, S Abstract: Measurement of dynamic behaviour of magneto-electric (ME) effect for sintered ceramics has been done by an experimental set-up involving several devices, designed and fabricated in our laboratory. In dynamic method ME signal is registered by measuring the electric potential across the sample under variable dc magnetic field in presence of an ac magnetic field. The relevant devices are dedicated for such measurements only with due consideration to their cost effectiveness. The primary devices begin with the poling system both (a) electric and (b) magnetic, to pole the magneto-electric ceramics. Because of the smallness of ME signal precaution against the noise catch-up is also considered with proper shielding. A lock-in device is used to detect and measure small signals accurately with proper choice of frequency tuned to the frequency of the signal as provided by the frequency generator. The performance of the fabricated devices has been found satisfactory in conducting the dynamic measurement of ME effect for ceramic magneto-electric materials. Page(s): 185-188 Tue, 01 Jun 2004 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/9284 2004-06-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/9283 Title: Coupled-admissible functions for simple solutions to unsymmetrically laminated shear flexible beams Authors: Singh, Gajbir; Nair, P S; Rao, G Venkateswara Abstract: Coupled-admissible functions are derived to obtain simple solutions for unsymmetrically laminated beams. A kinematically admissible variation, as allowed by Rayleigh-Ritz energy method, is assumed for the section rotation. Compatible admissible variations for transverse and axial displacements are derived by making use of equilibrium and boundary conditions. The proposed approach reduces the number of independent unknowns by a factor of three compared to traditional Rayleigh-Ritz method. Expressions for the axial and transverse displacements, section rotation, fundamental frequency and buckling loads for simply-supported, clamped-free and clamped-clamped beams are derived. Page(s): 169-177 Tue, 01 Jun 2004 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/9283 2004-06-01T00:00:00Z http://nopr.niscpr.res.in/handle/123456789/9282 Title: Determination of optimum switching angles for speed control of switched reluctance motor drive system Authors: Akhter, Hamid Ehsan; Sharma, Virendra K; Chandra, A; Haddad, Kamal Al Abstract: Turn-on angle and turn-off angle are the two switching angles that play a major role in deciding whether a switched reluctance motor (SRM) develops positive or negative, high or low electromagnetic torque. Switching angles are function of speed and change with acceleration, but this requires sophisticated and complex digital controllers for real time variation of switching angles as a function of rotor speed. This paper presents a methodology on the determination of fixed turn-on and turn-off angles that are optimum and provide satisfactory performance of the SRM drive during full-load operation. Experimental magnetization and static torque data are used for realistic simulation of dynamic response of a 4 kW, 4-phase, 8-pole stator, and 6-pole rotor configuration SR motor. The simulated performance of SRM drive system is presented to analyze the effect of different switching angles on full-load (25 Nm) starting performance of the drive in terms of speed, current and torque response. An optimum pair of turn-on and turn-off angle that ensures stable and satisfactory full-load operation is recommended. Page(s): 151-168 Tue, 01 Jun 2004 00:00:00 GMT http://nopr.niscpr.res.in/handle/123456789/9282 2004-06-01T00:00:00Z