Applied Mechanics and Materials Vol. 772

Abstract: Bifurcation of rupture path is studied for the effect of linear and nonlinear cubic damping. Momentum equation with Rayleigh factor was transformed into ordinary differential form. Bernoulli differential equation was obtained and solved by the method separation of variables. Analytical solutions yield the bifurcation of linear and nonlinear cubic damping was visible at imaginary part when the wave was non dispersive. For the dispersive wave, bifurcation of rupture path was invisible due to lower cubic damping. Amplitude attenuated during the seismic moment. Imaginary parts of the solutions illustrate the intersection or collision of soliton, for which, the bifurcation of rupture path is initiated. Intersection is not visible if the energy is well dispersed. Wave profile illustrates the existing of linear exciting and nonlinear damping effect during seismic moment.

Abstract: The vibration suppression of Timoshenko beams, subject to the random excitation, using the Distributed Tuned Mass Damper (DTMD) technology has been investigated in this study. The governing differential equations of motion of the Timoshenko beam with the attached DTMD system have been derived using extended Hamilton's principle, and solved utilizing the Finite Element Method (FEM). Comparing with the traditional TMD or DTMD design methodologies, in this study the design is focused on the attached mass (es) of the DTMD system under predefined stiffness (es) and damping factor (s). The validity of the established design methodologies have been verified through illustrated examples.

Abstract: A new approach substitutes the damper of a passenger car by a cardanic gimbaled flywheel mass. The constructive design leads to a rotary damper in which the vertical movement of the wheel carrier leads to revolution of the rotational axis of the flywheel. In this arrangement, the occurring precession moments are used to control damping moments and to store vibration energy. Different damper characteristics are achieved by different velocities of the inner ring. From almost zero torque output to high torque output, this damper has a huge spread. In this paper a control concept for a LQR is presented. The objective of the control is an adequate motion of the gyroscope to a desired damping characteristic of a passenger car.

Abstract: This paper simulated the non-linear sloshing effects under typical dynamic actions. The sloshing simulation is realized with the Arbitrary Lagrangian Euleria (ALE) formulation plus bi-phase hydrodynamic biomaterial liquid gas materials. The study first investigated two dimensional (2D) sloshing problems under harmonic excitations. Through calibration studies in standard rectangular tanks, the case study demonstrated reasonable agreement with numerical results published by other researchers. The study was then extended to more complicated three dimensional (3D) sloshing problems, with the fluid-structure interaction (FSI) considered. The simulation well reflected the sloshing behaviours in a steel tank subject to given seismic excitations and provided available prediction for structural performance. The obtained results show that the used method is helpful for seismic design of liquid tanks.

Abstract: This study presents a modeling procedure and dynamic analysis for a novel hydro-pneumatic suspension system, in which the gas chamber has been integrated into the main structures. The modeling of the novel hydro-pneumatic suspension system has been established based on the mass conservation and force balance and the dimension has been obtained through a design optimization approach. The simulation results of the established model have been compared with those obtained through ADAMS, and good match can be observed.

Abstract: Servo press machine can enable us to high precision, but the dynamic behavior does not seem to be considered well. In order to improve the accuracy in manufacturing, it has been discussed effectiveness of reducing the elastic deformation of die structure on forming by mechanically compensating die structure which includes a servo die cushion system.

Abstract: Analytical solution of the axisymmetric two-dimensional non-Fourier temperature field within a hollow sphere is investigated considering Cattaneo-Vernotte constitutive equation with general time-dependent heat flux. The material is assumed to be homogeneous and isotropic with temperature-independent thermal properties. The method of solution is the standard separation of variables method. Duhamel integral is used for applying the time-dependent boundary conditions. The presented solution is applied to special case of harmonic heat flux on outer surface.

Abstract: This paper presents the principle diagrams that can be used to manufacture hydraulic systems that can prevent the seizing of the circular hydrostatic guideways of the table in the case of heavy-duty vertical lathes, with over 4000 mm diameter. The proposed systems will provide the lubrication of the guideways of the table as long as this one rotates up to a possible stop caused by an accident. Lubrication is achieved even in the absence of the machine supply voltage because it is provided by systems that do not need electrical power to operate. The absence of hydrostatic pressure, even in only one of the hydrostatic pockets, caused by the breaking of a hose, can be detected and will trigger the safety system activation.

Abstract: Development of design software in the last two decades has led to marketing products with complex shapes; which, cannot be materialized without the aid of the computer. For some product development processes, reverse engineering (RE) allows generating surface models by three-dimensional scanning techniques, and consequently this methodology permits to manufacture different parts and tools , shortening the development time. The paper presents a redesign process applied on a thin walled plastic component using the Reverse Engineering technique. The part was scanned, modified and subject to simulations that will certity the flow and filling of the cavity.

Abstract: In this paper a model of the feed drive system with disturbance force for High Speed Cutting (HSC) linear motor machine is given. The dynamic stiffness for the proposed model is analysed. A simulation of the influence of some parameters on feed drive dynamic stiffness is performed with the simulation program MATLAB & SIMULINK. Correctness of the proposed model is verified with an experimental measurement of the dynamic stiffness of the feed drive on the prototype HSC linear motor machine (HSC 11).