Research On Dynamic Modeling And The Factors Of Bolted Joints

Since the bolted joints in the mechanical structures have significant influence on thedynamic characteristic of mechanical assembly, therefore， the academic research ofdynamic characteristics of bolted joints are important. This thesis takes the bolted joints ofthe assembly as case study, research on dynamic modeling and the factors of bolted jointsare done both in simulation and experiment.First, depending on the research progress in the world, different methods of dynamicmodeling in bolted joints are stated at first, the advantages and disadvantages of thesemethods are got. Basing on a dynamic parameterized modeling approach on bolted joints inmechanical assembly using virtual material, vibration modes of virtual material model arein excellent consistence with experimental results, the relative errors between the simulationnatural frequencies and the experimental ones are less than6%. It shows that the virtualmaterial dynamic modeling to simulation bolt preload effect is reasonable.Then, based on the simulation and experiment research of the different preload, usingHertz contact theory，the influence of bolt preload on the microcontacts is studied. therelation between the natural frequency and bolt preload is got. As the bolt preload increases,the natural frequency increases; preload increases to a certain degree, modal frequencyslower growth. In addition to analyze the bolt from the distribution and the amount of jointsurface vibration characteristics influence, pointed out that the current of the virtual materialmethod without considering the distribution of the bolt.The fundamental purpose of studying the bolted joints characteristics is engineeringapplications. Considering the effects of vibration characteristic of bolted joints, the dynamicmodel of fixed bolted joints and mpc are carried by UG, Solidworks and Patran. theapplication to the modal analysis of the linear motor is successful.