III. MULTIPHYSICAL MODELING OF THE SRM The noise, harshness and vibration of electrical machines can be analyzed in depth by means of advanced multiphysic modeling, simulation and validation tools only , . Therefore a comprehensive co-simulation workflow was designed, in which complex simulation platforms are coupled, as seen in Fig. 3 . In the same figure, all the main components of the developed workflow together with their inputs and outputs can be easily distinguished.
The modal analysis is performed so as to achieve two „traveling” wave type of vibration modes, for the 24.342 KHz and 33.862 KHz frequencies. The two vibration modes are illustrated in Figure 7. The number 13 mode of vibration of the turret drive actuator displays a frequency close to that of the sector laminated piezoelement.
This paper studies the effect of noise and friction on performance of the chain drive system for motor bikes. Experiment shows that chain transmission in chain drive system leads to poor overall performance, due to its noise and chain gets loose due to aging and sprockets wear due to chain friction etc., the proposed system consists of drive and driven pulley with timing belt transmission. Compared to conventional method, proposed method give improved tension in pulleys and belt by the additional arrangement called belt tensioner. This gives good overall performance of the system, and reduces noise, vibration and gives high transmission speed. Keywords : Timing belt, Transmission system, Belt drive.
It is worth mentioning that the observation of the peak accelerations measured during vibra- tion is a very rudimentary method of assessing the severity of vibration since they are very sen- sitive to short nonrepresentative transient vibration events (Reynolds & Pavic 2006). They are also highly dependent on the data acquisition equipment and parameters used, particularly the methods of filtering. As a result, this method of vibration magnitude assessment is becoming obsolete and not recommendable.
Figures 8 to 10 represent some of the identified modal configurations associated with the most relevant natural frequencies. In those figures the symbols • define the position of the towers and in- termediate supports. Due to the significant interac- tion observed between some global vibration modes and with cable vibrations, more sophisti- cated algorithms were explored to provide a better identification of modes, namely the Enhanced Fre- quency Domain Decomposition (EFDD) and the data driven Stochastic Subspace Identification (SSI) methods. These methods provided also esti- mates of damping ratios (Magalhães, 2004).
By contrast, this commonality of odor character is precisely what is expected of a vibrational mechanism. Regardless of molecular shape and connectivity, the bands of C-H stretch, wag and scissor modes will shift predictably and collectively in frequency between hydrogen and deuterium isotopomers. In similar fashion, vibration theory can successfully account for the commonality of the odor of molecules of different structures that contain the same functional groups [sulfuraceous, nitric, ethereal, etc.], a phenomenon both familiar and otherwise unexplained by shape theory . Furthermore, vibrational spectra appear to be a better predictor of odor character than shape descriptors [25– Table 1. Results of human discrimination tests between GC-
The present work has a triple objective: (i) to present the main ideas and theoretical elements in- volved in the design of overlapping semi-decentralized controllers via the inclusion principle; (ii) to discuss the more general and practically interesting problem of designing multi-overlapping controllers, paying special attention to the longitudinal multi-overlapping case; and (iii) to illustrate the main ideas involved in the de- sign of overlapping controllers in the context of the Structural Vibration Control of tall buildings under seismic excitation. The organization of the paper is as follows: Section 2 gives necessary background results about the inclusion principle and the design of overlap- ping controllers, with a detailed discussion of the LQR case. Section 3 presents the multi-overlapping prob- lem. In Section 4, state-space models for a particular five-story building with direct and inter-story actua-
In this paper the effectiveness of a solid particle damper to control structural vibration is experimentally investigated. The vibration control performance and its influencing parameters are examined by a Multi Degree of Freedom (MDOF) structure attached with a particle damper (PD) under horizontal excitation. In a particle damping system damping is achieved using solid particles or granules and is a passive damping method. Here the enclosure filled with particles is attached to the primary structure undergoing vibration. As the primary structure vibrates, particles undergo inelastic collision within the enclosure resulting high amount of energy dissipation. Based on the analytical study of undamped frame in ANSYS WORKBENCH, dimensions of the frame were fixed and shake table study of a two storied steel frame with and without damper system are carried out. Results shows that effectiveness of damping depends on various parameters like mass, particle size, shape etc. The effectiveness is compared with a friction damper (FD) and is observed that PD is more efficient than FD since 31.80% energy is dissipated more in PD compared to FD
Means consumer behavior as research activities directly involved in obtaining, consuming and disposing of products and services, including the decision processes that precede and follow these actions. The factors that influence the buying behavior of vehicle. Thus, organizations must attract, retain and satisfy customers, whereas the satisfied customer will greatly expand its profitability and competitiveness. In this context, this article aims to identify in order of importance the factors that influence consumer behavior of vehicles in dealer Dan Silveira Motors Ltd,, in Campina Grande – PB. To achieve the proposed objective, methodology, based on exploratory, descriptive and bibliographic research, field, case study, qualitative and quantitative involving a sample of 150 clients of Dan Silveira Motors Ltd. was used. The dimensions of the research were: cultural (culture, subculture and social class); social (reference group, and family roles and status); Personal (age and stage of life cycle, occupation, economic circumstances, lifestyle and personality); psychological (perception, learning, memory, beliefs and attitudes). The instrument used was a questionnaire with fifteen (15) objective questions, being assertive for each variable, which were measured using three categories adapted the Likert scale, namely: agreement, neutrality and disagreement. The results, the majority agreed that all factors influencing worked consumer behavior, highlighting the most relevant, personal factors; and as less important, cultural.
Another factor with relevant influence on the natural frequencies is the amplitude of the bridge vi- bration, which is essentially related with the traffic intensity. This dependency is characterized in Figure 13 for the first bending mode, during the first week of March and using the root mean square value (RMS) as a measure of the vibration intensity. The second mode is the one from the twelve analysed modes that experiences higher daily fluctuations. This night be explained by the relevant movement in the longitudinal direction associated with this mode, that is influenced by the friction forces of the abut- ment bearings. For low vibration amplitudes the bearings behave has a fix connection, whilst for large amplitudes the friction forces are overcome and, as a consequence, the natural frequency de- creases (it is worth noting that the scale associated with the RMS is inverted).
The application of this method in the case of compressor driving synchronous motors presents difficulties in the practice, because, in the majority of the studied cases, difficulties occur at the determination of the data necessary for the calcula$ tion.
The aim of this contribution is to extend the techniques of composite materials design to non-linear material behaviour and apply it for design of new materials for passive vibration control. As a first step a computational tool allowing determination of macroscopic optimized one-dimensional isolator behaviour was developed. Voigt, Maxwell, standard and more complex material models can be implemented. Objective function considers minimization of the initial reaction and/or displacement peak as well as minimization of the steady-state amplitude of reaction and/or displacement. The complex stiffness approach is used to formulate the governing equations in an efficient way. Material stiffness parameters are assumed as non-linear functions of the displacement. The numerical solution is performed in the complex space. The steady-state solution in the complex space is obtained by an iterative process based on the shooting method which imposes the conditions of periodicity with respect to the known value of the period. Extension of the shooting method to the complex space is presented and verified. Non-linear behaviour of material parameters is then optimized by generic probabilistic meta-algorithm, simulated annealing. Dependence of the global optimum on several combinations of leading parameters of the simulated annealing procedure, like neighbourhood definition and annealing schedule, is also studied and analyzed. Procedure is programmed in MATLAB environment.
Fig.6 shows the nonlinear vibration behavior of single-, double- and triple-walled CNTs. The results indicate that the increase of the number of the walls results in a less nonlinear vibration response. Due to the influence of the vdW interaction, all the walls of the CNT vibrate as a whole. Then the frequency can be approximated by the properties of the middle tube only. As the number of tubes increases, the effective radius of the MWCNT becomes bigger too, and thus the nonlinearity of its vibration decreases. Also, it can be seen that as the number of tubes increases, the free vibration frequency of the innermost tube increase as well. This results in the increase of the vdW forces. And the influence of vdW interaction on the vibration frequency can also be seen from the above results. Almost all the frequencies are different with the natural free vibration without the vdW interaction.
Procedures / Method for problem solution: This study is characterized as a qualitative and explanatory research, as it comprises a social group and the occurrence of a phenomenon. For data analysis was used the method of content analysis using five categories of analysis, because it allows the classification of elements and the grouping of evidence by similarity. In view of the shift from the automotive sector to the financialization process, consider yourself the predominance of practices that prioritize traditional financial logic control instruments is considered. In this context, the Jaguar Land Rover Group undergoes changes to remain competitive due to new control concepts in validity. Observing this context, this research will conduct a case study in the JLR group. To this end, the methodology used as a form of data collection is the document analysis technique. This was accomplished in annual reports of the automaker, in financial reports of Holding Tata Motors, in specialized websites of the financial market and the automaker itself.
The physical parameters of rubber (A), steel (B) and concrete (C) are listed in Table I. The material properties described were obtained from . The filling fractions in Table I were defined as =S A /S C and =S B /S C , where S A , S B, and S C are the cross-section areas of the coating (rubber), considering it filled, core (steel), and unit cell, respectively. The filling fractions for square and triangular lattices are addressed in . It can be observed from Table I that the coating rubber has very small Young’s modulus, i.e., very small elastic constants, and consequently very low sound propagation velocity. This is the basic condition for the existence of local resonances, since it facilitates the vibration of the steel core inclusions .
The dynamic behavior of the long beam can be obtained through the analysis of small vibration about the static equilibrium of a finite elements model of the structure (Ferris and Afonta , Sallstrom et al. , and Santillan et al. [14–16]). Vibration analysis and experimental validation of a finely meshed finite element model of a tip pulled beam was carried out by Holland et al. . The present work proposes the combination of a nonlinear static deformation model of the same structure and a courser finite element model of the deformed beam in order to assess its dynamic characteristics. Results of the different modeling strategies are compared and discussed.