Author : S.A. Halkude, M.G. Kalyanshetti and Y.N.Bansode

Turbo generators are used for generation of electricity in large power plant which normally rest on frame foundation. These foundations are subjected to dynamic loading that result in higher section of beam and column. In the present work an attempt is made to optimize sizes of column & beam by incorporating different bracing systems. The analysis is carried out by ‘Combined method’ which computes the value of governing parameters, frequency & amplitude for satisfactory performance. The study focuses on the investigation of effectiveness of various bracing system i.e. ‘V’ bracing, ‘A’ bracing & ‘Knee’ bracing. The study reveals that, frequency is not a significant governing parameter as for all the cases of bracing system, frequency is observed to be within the permissible limit. However, variation in the amplitude for different type of bracings is significant. Therefore, bracing type is one of the important considerations in foundation design for controlling amplitude. This study reveals that frame foundation with ‘V’ bracing shows improved performance over bare frame; ‘A’ bracing shows improved performance than ‘V’ bracing and ‘Knee’ bracing shows best performance amongst all bracing types. Overall, in the given structural configuration, amplitude produced by ‘Knee’ bracing is almost 42 % lower than bare frame which significantly advocates the effectiveness of ‘Knee’ bracing. Therefore, even for reduced geometry of structural members, ‘Knee’ bracings are found still effective & workable resulting into overall economy.

Keywords: Amplitude, Frequency, Foundation, Combined method, Rotary Machine, Frame foundation, Bracings

Article published in International Journal of Current Engineering and Technology, Vol.7, No.3 (June-2017)