Dynamic Modeling of a Boring Bar Using Theoretical and Experimental Engineering Methods Part 1: Distributed-Parameter System Modeling and Experimental Modal Analysis

Abstract

Boring bar vibration is a common problem during internal turning operations and is a major problem for the manufacturing industry. High levels of boring bar vibration generally occur at frequencies related to the first two fundamental bending modes of a boring bar. This is the first of two companion papers that summarize the theoretical and experimental work carried out concerning modeling of dynamic properties of boring bars. This paper introduces the Timoshenko beam theory for the modeling of clamped boring bars. Also, the traditional Euler-Bernoulli beam theory is applied. These continuous system methods have been utilized to produce fixedfree beam models of the clamped boring bar. In order to improve accuracy of dynamic models of clamped boring bars, the modeling of the boring bar clamping is addressed by means of multi-span beam models with pinned boundary conditions. The derived boring bar models have also been compared with results obtained by means of experimental modal analysis, conducted on the actual boring bar clamped in a lathe. The multi-span beam boring bar models display higher correlation with experimental modal analysis results as compared to fixed-free beam models. For the fixed-free beams the Timoshenko model results in the highest correlation with the experimental results. On the other hand, the interval in frequency and the orientation of the two fundamental modes demonstrate differences, particularly between the continuous system models and the experimental results.

Analysis of the Composite Boring Bar Dynamic Characteristics Considering Shear Deformation and Rotational Inertia

“…According to the uniform Euler-Bernoulli beam theory, the differential equation of motion is as follows [29]:…”

Analysis of the Vibration and Chatter Stability of a Tapered Composite Boring Bar

“…To overcome the chatter problem of metal materials, many scholars [1][2][3][4][5][6][7][8][9][10][11][12][13] have conducted studies and found that chatter is often generated by three factors, i.e., ripple regeneration, mode coupling, and friction. In the study of ripple regeneration (which is caused by surface ripples), Luo et al [14] adopted a hybrid digital method to solve the problem of surface ripple regeneration.…”