ABSTRACT This article describes the results of an investigation concerning the power absorbed at mechanical resonance for a single degree of freedom vibration system. Regarding the experimental purposes, the article proposes a cantilever... more
ABSTRACT This article describes the results of an investigation concerning the power absorbed at mechanical resonance for a single degree of freedom vibration system. Regarding the experimental purposes, the article proposes a cantilever beam set-up actuated by a voice-coil actuator and a computer-aided power monitoring technique. The absorbed power is evaluated in a steady-state regime for different values of excitation frequency around the resonance (the first mode of vibration). The experimental results are afterwards compared to the theoretical predictions. In addition, some transient regimes generated by beat vibrations are explored. The negative absorbed power has been observed. The article proposes an active vibration damping technique, based on actuation with a negative modal power supply.
This paper aims to examine in experimental terms some new research opportunities on the dynamic behaviour of the mechanical systems with piezoelectric actuation, using the energetic parameters evolution (especially the electric active... more
This paper aims to examine in experimental terms some new research opportunities on the dynamic behaviour of the mechanical systems with piezoelectric actuation, using the energetic parameters evolution (especially the electric active power or real power as well) captured from the supply circuit of the actuator. The study is carried out on an experimental setup which consists of an aluminium
This paper aims to examine in experimental terms some new research opportunities on the dynamic behaviour of the mechanical systems with piezoelectric actuation, using the energetic parameters evolution (especially the electric active... more
This paper aims to examine in experimental terms some new research opportunities on the dynamic behaviour of the mechanical systems with piezoelectric actuation, using the energetic parameters evolution (especially the electric active power or real power as well) captured from the supply circuit of the actuator. The study is carried out on an experimental setup which consists of an aluminium
One of the most important parameters used in the evaluation of machining technological systems is the dynamic quality, represented by the system stability and the specific feature of the reaction to the external factors, during the... more
One of the most important parameters used in the evaluation of machining technological systems is the dynamic quality, represented by the system stability and the specific feature of the reaction to the external factors, during the machining process. The dynamic quality of the machining system is given by the dynamic quality of the machine tool, cutting tool, cutting tool holding device, workpiece fixture. The dynamic behavior of the machining system is given by the stiffness of the elastic subsystem of the workpiece and tool. In the case that the deformation of the machine tool is small in relation with the two subcomponents of the technological system, mentioned, these can be studied separately. It is important to determine which is the weakest link of the technological system or to determine which is the component that can lead to the loss of the stability of the entire system. In the paper it is studied the dynamic behavior of the turned long, flexible workpieces. The workpieces are clamped in the lathes chuck and in the tailstock. The natural vibrational frequencies are determined according to a series of parameters as the diameter of the workpieces, axial forces applied by the tailstock.
Fixtures are used for orientation-positioning-tightening of workpieces during machining on machine tools. Multiple clamping fixtures are intended to clamp several workpieces for simultaneous or successive machining. Multiple clamping is... more
Fixtures are used for orientation-positioning-tightening of workpieces during machining on machine tools. Multiple clamping fixtures are intended to clamp several workpieces for simultaneous or successive machining. Multiple clamping is characterized by a series of economical advantages, due to the reduction of total machining time. These advantages are more important once the number of workpieces is higher or if the machining is made with compound tools. Due to the complexity, overall size and the high number of components, the multiple clamping fixtures have diminished accuracy than simple fixture due to elastic and contact deformations of fixtures housing, of supports etc. Also, multiple clamping fixtures present diminished rigidity and dynamic stability. From the analysis of the specialized literature results that there are a few paper on the subject of multiple clamping. In the paper there are presented the causes that can lead to the diminishing of the accuracy of multiple fixture. The modalities for the determination of fixtures precision are presented, also, for the parallel and serial multiple clamping fixtures.
This paper aims to examine in experimental terms some new research opportunities on the dynamic behaviour of the mechanical systems with piezoelectric actuation, using the energetic parameters evolution (especially the electric active... more
This paper aims to examine in experimental terms some new research opportunities on the dynamic behaviour of the mechanical systems with piezoelectric actuation, using the energetic parameters evolution (especially the electric active power or real power as well) captured from the supply circuit of the actuator. The study is carried out on an experimental setup which consists of an aluminium
