Finite element modal analysis or frequency analysis has been well known as an effective numerical calculation and simulation method to find natural frequency and associated mode shape of object or structure. However, its result accuracy is questionable without field vibration measurement data and model calibration. In addition, getting complete boundary condition such as geometry dimensions of structure, material property, and contact/support property of assembly parts is not very straightforward in many cases as experienced and skilled analyst is required for model simplification while still maintains acceptable results. This presentation will discuss on how to apply this method in conjunction with conventional vibration analysis work, experimental modal analysis or operating deflection shape analysis of machine structures and pipework identifying resonance problem and proposing structure modification for correction. Example works and case study of various applications and field operation constraints will be presented with success results.
Keywords: finite element modal analysis, frequency analysis, experimental modal analysis, operating deflection shape analysis, structure vibration, resonance
Roengchai Chumai is founder and technical director of Machinosis Company Limited, a consulting and engineering company in the field of machinery condition monitoring and diagnostics located in Rayong, Thailand. He started his career with Bently Nevada (Thailand) Limited in 1999 as a machinery diagnostics engineer before the company was taken over by General Electric in 2002. He is responsible for machinery vibration testing, analysis and troubleshooting, field balancing, rotor dynamics modeling and analysis. He was a technical leader of machinery diagnostics group for Asia region including Australia and New Zealand in 2008 until he left the company in 2015. He holds a bachelor degree in mechanical engineering from King Mongkut’s University of Technology Thonburi and a master degree in management science from Asian University. He is a certified vibration analyst Cat. IV according to ISO standard and a member of ASME.