Study on dynamic characteristics analysis of CNC pipe thread lathe based on the energy of modal effective mass

Abstract

Owing to the modal analysis of complex structure system exist in the problems such as the local mode cannot be identified and the overall modal vibration mode cannot be extracted, this study deduces a formula of modal effective parameters based on the kinetic energy and introduces to the simulation of mechanical characteristics of the SCK230 CNC pipe thread repair the lathe bed. The simulation shows that this method can identify the local mode of three directions effectively, and determines whether the numbers of solved modalities satisfy the requirement of precision. In order to improve the natural frequencies of the bed and analyse the influence of the opening of the bed on its dynamic performance, three optimisation schemes are proposed based on this, and verified the feasibility of the optimisation scheme. Through structural optimisation, improve the dynamic characteristic of the lathe bed and reduce the manufacturing cost, and the optimisation of the structure can be achieved without experimental modal analysis.

Keywords

• computerised numerical control
• pipes
• vibrations
• modal analysis
• optimisation
• lathes
• dynamic characteristics analysis
• modal effective mass
• complex structure system
• local mode
• modal vibration mode
• modal effective parameters
• kinetic energy
• mechanical characteristics
• SCK230 CNC pipe thread repair
• lathe bed
• natural frequencies
• dynamic performance
• optimisation scheme
• structural optimisation
• dynamic characteristic
• experimental modal analysis
• manufacturing cost