王欣.pdf.doc

Mechanism and Machine Theory Mechanism and Machine Theory 39 (2004) 1307 – 1320 ate/mechmt Studies in dynamic design of drilling machine using updated finite element models . Bais a,*, . Gupta b, . Nakra c, . Kundra c a Bharat Heavy Electricals Limited, Hyderabad, India b Instrument Research & Development Establishment, Dehradun, India c Department of Mechanical Engineering, IIT Delhi, Delhi, India Accepted 25 May 2004 Available online 2 October 2004 Abstract The aim of the present work is to develop updated FE models ofa drilling machine using analytical and experimental results. These updated FE models have been used to predict thee? ect of structural dynamic modifications on vibration characteristics of the drilling machine. Two studies have been carried out on the machine. In the first study, modal tests have been carried out ona drilling machine using instrumented impact hammer. Modal identification has been done using global method of modal identification. For ana-lytical FE modeling of the machine, puter program has been developed. The results obtained using FEM, have been correlated with the experimental ones using mode parison and MAC values. Analytical FE model has been updated, with the help ofa program, which has been developed using direct methods of model updating. In the second study, modal testing has been carried out using random noise gen-erator an