The paper presents a new approach to the parameter identification of a wind turbine shaft vibrations measured with piezoelectric sensor. The system order and unknown processes matrices are determined using the wind force as the model input and wind turbine shaft vibrations as the model output. The identified model can be used to estimate the shaft vibrations and design an early damage monitorin...

We report the results of a three-year study of bifocal fractures of the tibia and fibula, excluding segmental shaft fractures. In our whole series, these formed 4.7% of all tibial diaphyseal fractures. We describe three groups: bifocal fractures of both the proximal and the distal joint surfaces, fractures of the shaft and tibial plateau, and fractures of the shaft and ankle. These groups of fr...

Introduction This paper summarizes my collection of research findings on the role of shaft flexibility in the golf swing. The research was initiated during my PhD thesis under the supervision of Dr. Eric Sprigings. The goal was to gain a comprehensive understanding of the role that shaft stiffness plays in the golf swing. This paper will provide a rationale for the methodologies I’ve used, a su...

In this study, two-dimensional electro-mechanical analysis of a composite rotating shaft subjected to non-axisymmetric internal pressure and applied voltage is investigated where hollow piezoelectric shaft reinforced by boron nitride nanotubes (BNNTs). Composite structure is modeled based on piezoelectric fiber reinforced composite (PFRC) theory and a representative volume element has been cons...

OBJECTIVE To investigate the clinical characteristics, treatment options and causes of misdiagnosis of ipsilateral femoral neck and shaft fractures. METHODS Among 20 patients with ipsilateral femoral neck and shaft fractures, 19 were treated operatively and 1 was treated conservatively. Sixteen cases of femoral shaft fractures were treated by open reduction and internal fixation with compress...

The primary goal of the this paper is to summarize field demonstrations of the feasibility of detecting changes in blade and shaft natural frequencies (such as those associated with a blade or shaft crack) on operating machinery using non-contact, nonintrusive measurement methods. This paper primarily addresses the results of application of this nonintrusive torsional vibration sensing to: a la...

A typical dynamometer drive shaft was damaged during its working condition. This failure was repeated in four cases. In the present article, a failure analysis of a dynamometer drive shaft has been performed. To analyze the failure, the material investigation was carried out by scanning electron microscopy (SEM) images. Additionally, the micro-structure of the failed coupling shaft was photogra...

The shaft deflection is one of critical factors that deteriorate the grease lubrication state inside the tapered roller bearings (TRBs). So, in this paper, on the premise of the TRB subjected to the combined loads and the shaft is deflected, the grease lubrication model at the TRB contacts was constructed, in which the interaction loads, linear and angular displacements of the bearing parts wer...