Optimal Design of a Damped Arbor for Heavy-Duty Machining of Giant Parts

Abstract

Aiming to suppress chatter vibration during machining of huge mechanical parts, dies, and molds, a design method for a damped arbor imbedded with a mass damper was devised. First, an analysis method coupled with Rayleigh's method was developed and used to calculate the stiffness of an arbor with a tapered hollow space for installing the mass damper inside. In the formulation of the vibrating system with two degrees of freedom, the displacement ratio is introduced for accurate calculation of the counter force of the damper mass. Then, the shape and size of the hollow space was optimized in order to maximize the negative real part of the compliance of the arbor. The proposed design method can increase the dynamic stiffness of the damped arbor with a hollow with the minimum reduction in its static stiffness. Furthermore, it is found that once the damper is optimized for the maximum length of an arbor in a certain design range, it can be applied to a shorter arbor without deterioration of dynamic stiffness. Finally, chatter noise and machined surface roughness measured experimentally proved that a damped arbor prototyped by the proposed design method has much higher cutting performance than a conventional one.

Comparative Study of Machining Technology Selection to Manufacture Large-Size Components of Offshore Constructions

“…The main tendency in the design of large-size machine tools is to ensure possibility of machining axial-symmetric parts on CNC milling centres and prismatic parts on CNC lathe with a controlled rotation of a rotary table for obtaining required geometry and tight tolerances [5,13]. Technological problems which can be easily solved on conventional size machine tools represent a huge challenge for big and accurate dimensions, mostly within a tolerance grade of IT7, and obtained on large-size machine tools.…”

“…wind turbines), maritime industry, including offshore platforms as well as shipping equipment. Components of such kind are often machined by specially developed machine tools: workshop or portable machines for in-situ manufacture and inspection [9,11,13,16]. Significant aspects related to manufacturing and possibly maintenance and repairing of large-size and accurate parts are indicated in Fig.1.…”

Improving Production Efficiency of Large Size Molds as a Result of Innovative Quality Control Process

“…The development of the metal sector is in line with the current trends in the implementation of advanced production processes using modern technologies, including, among others, manufacturing and machining of components from special materials such as elements of engines, gears and complete transmission gears, as well as large-size components such as rotor hubs of wind farms, matrices and molds for the high pressure die-casting of light alloys etc. (Haddag et al, 2016;Shimizu et al, 2001;Onozuka et al, 2013;Nowicka-Skowron and Ulewicz, 2015). It should be emphasized that an important stage of the production process of each large-size component is quality control, as a result of which basic parameters of the manufactured product and, above all, compliance with the customer's requirements are checked.…”

Analysis of vibration behavior of damped tool arbor by finite element method

“…m d , k d and c d are the modal mass of the weight, the stiffness of the spring, and the damping coefficient of the damper, respectively. The design parameters of the vibration system are optimized by being approximated as a 2 degrees of freedom system of a particle model as shown in Fig.4 (Onozuka, et al, 2013). In this model, m 1 , k 1 , and c 1 are modal mass, modal stiffness, and modal damping coefficient of the end of cutting tool, respectively.…”