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The Voigt-type of dynamic vibration absorber is a classical model and has attracted considerable attention in many years because of its simple design, high reliability and useful applications in the fields of civil and mechanical engineering. Recently, a non-traditional type of dynamic vibration absorber was proposed. Unlike the traditional damped absorber configuration, the non-traditional absorber has a linear viscous damper connecting the absorber mass directly to the ground instead of the main mass. There have been some studies on the design of the non-traditional dynamic vibration absorber in the case of undamped primary structures. Those studies have shown that the non-traditional dynamic vibration absorber has better performance than the traditional dynamic vibration absorber. However, when damping is present at the primary system, there are very few studies on the design of non-traditional dynamic vibration absorber. This article presents a simple approach to determine the approximate analytical solutions for the H∞ optimization of the non-traditional dynamic vibration absorber attached to the damped primary structure subjected to force excitation. The main idea of the study is based on the dual criterion suggested by Anh in order to replace approximately the original damped structure by an equivalent undamped structure. Then the approximate analytical solution of dynamic vibration absorber’s parameters is given by using known results for undamped structure obtained. The comparisons have been done to verify the effectiveness of the obtained results. [ABSTRACT FROM PUBLISHER]

The purpose of this research is to propose a mechanical design and kinematic analysis for a pick-and-place mechanism (PPM), which is applied to automation equipments and press fabrication industries. To obtain all the possible dimensions of gear pairs, a programming software is developed by using Visual Basic (VB) language. From the path of motion, the geometric relationship between the planetary gear and internal gear will generate an approximate square path (ASP). By intercepting some portion of this ASP and utilizing one servomotor to drive the arm of the planetary gear, a new type of PPM is designed. To verify its performance, experiments and numerical simulations of motion analyses are performed and compared. The PPM could also be combined with other mechanisms to construct new systems with one input servomotor and multiple output manipulators. [ABSTRACT FROM AUTHOR]