Critical speeds of multi-mass and multiple elastic bearing systems

This work investigates the bending critical speed problem for acomplex rotor-bearing system. The main objective is to prepare aFORTRAN IV computer program for the Honeywell 6080 computer, thatcalculates the critical speeds of rotating shafts. The system mayinclude bearinr,s, couplings, and extra masses (non shaft mass), anddiscs for the gyroscopic effect. Shear deflection is· alsotaken into account, and provision is made in the program for Sectionsof the shaft that are tapered. The boundary conditions at the ends ofthe shaft can be fixed (deflection and slope equal to zero). Thefixed end condition enables the program to calculate the naturalfrequencies of cantilever beams. The advantages of this method areless data preparation and better approximation of the distributionof the mass ef the shaft. A main featur~ of the program is thenature of the output. The plotter is used to produce the deflectionat the critical speeds, moment versus speed curve and critical speedsagainst bearing stfffness curves.The secondary objective is to check the program against experimentalresults and other numerical techniques.