The strong growth within the wind technology market, underpinned by policy goals around the world, has highlighted the demand for advanced engineering analysis to improve wind turbine (WT) design, both in terms of reliability and design of larger turbines. This paper presents a review of the latest research that has been carried out in modeling and analysis of load transmission in WT drive train systems and their components. Common failure roots are elaborated, and probable hypotheses are presented. A modeling approach is derived by classification into engineering, mathematical and computational models with a focus on gearbox modeling efforts. Precise understanding of drive train system dynamics and load transmission is necessary for a cost efficient and robust system design to enhance reliability and reduce the maintenance costs. Design optimization of WTs and their subsystems will make future WTs more attractive compared with fossil and nuclear power plants, and it is therefore an important issue for a more sustainable environment.

The paper deals with application of giant magnetostrictive materials for power harvesting from vibration. Mathematical modelling and design of magnetostrictive electric generators (MEG) are considered. The mathematical model, original MEG and test rig have been developed for simulation and experimental study of conversion of mechanical energy of vibration into electrical energy using Terfenol-D as an active material. Simulation and experimental results have confirmed functionality of designed MEG. Generator using Terfenol-D rod with 50 mm in length and 15 mm in diameter has shown efficiency of the transduction processes up to 25% with maximum power generation up to 240 W.

In this paper the novel design of Galfenol based vibration energy harvester is presented. The device uses Galfenol rod diameter 6.35 mm and length 50mm, polycrystalline, production grade, manufactured by FSZM process by ETREMA Product Inc. For experimental study of the harvester, the test rig was developed. It was found by experiment that for given frequency of external excitation there exist optimal values of bias and pre-stress which maximize generated voltage and harvested power. Under optimized operational conditions and external excitations with frequency 50Hz the designed transducer generates about 10 V and harvests about 0,45 W power. Within the running conditions, the Galfenol rod power density was estimated to 340mW/cm3. The obtained results show high practical potential of Galfenol based sensors for vibration-to-electrical energy conversion, structural health monitoring, etc.

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In this paper, the feasibility of the application of a dual mass flywheel (DMF) for heavy-duty truck drivetrain systems was studied. The third engine order vibration harmonic was in the focus of analysis as one of the most significant contributions to the oscillatory response in the drivetrain systems of heavy-duty trucks. Global sensitivity analysis (GSA) and Pareto optimization were used for designing torsional vibration absorbers in an operating engine speed range of 600–2000 rpm. The optimization method attempted both to minimize the oscillations of the torque at the transmission input shaft and to maximize the energy efficiency of the vibration absorber. The GSA enabled the appropriate scanning of the domain of design parameters by varying all the parameters at the same time. It provided deep insight into the design process and increased the computational efficiency of the optimization. The results obtained show the following: the solution of the bi-objective optimization problem for torsional vibration absorbers does exist; Pareto fronts were obtained and analyzed for the DMF, presenting a trade-off between the measure of the attenuation of the oscillations of the torque at the transmission input shaft and the measure of the energy efficiency of the absorber; the optimized mass inertia, stiffness and damping parameters of a DMF do exist, providing the best attenuation of the torque oscillations; the performance of a DMF was further enhanced by incorporating a torsional tuned mass damper with appropriate optimized parameters. Finally, the results show evidence of the feasibility of the application of dual mass flywheels in heavy-duty truck drivetrain systems.

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In this paper a computational model of a horizontal axis washing machine is presented. The model has been built using a theoretical-experimental methodology consisting of integration of multibody system (MBS) formalism, detailed modeling of machine functional components and experimental data based validation. The complete model of a washing machine is implemented in the commercial MBS environment Adams/View from MSC.Software.An undesirable impact of washing machine operation on the surroundings is vibration and noise. The impact comes from system dynamics and poorly distributed load inside the drum, creating an imbalance. To get insight into vibration dynamics extensive simulations have been performed for washing machines in service as well as for machines in the developing stage by using the created computational model. This paper presents several results of numerical studies of the vibration dynamics of washing machines including the study of sensitivity of system dynamics with respect to suspension structural parameters, and the results of investigation of the potential of the automatic counterbalancing technology for vibration output reduction. In particular, simulations of the considered two plane balancing device has shown an existing significant potential in eliminating unbalanced load at supercritical spinning speed, resulting in a substantial vibration reduction in washing machines.Commemorative Contribution.