Modal parameter extraction of high speed shafts is of critical importance in mechanical design of turbo-pumps. Due to the complex geometry and peripheral components of turbo-pumps, difficulties can arise in determination of modal parameters. In this study, modal properties of a turbo-pump shaft, was studied by experimental modal analysis, and using different excitation techniques. An innovative...

transportation vehicles has motivated research in low frequency, structural-acoustic analysis. The internal sound field in the enclosed cavity is significantly affected by the acoustic modal characteristics of the cavity, by the dynamic behavior of the surrounding structure, and by the nature of the coupling of these two dynamic systems. The present work is intended to cast more light on the ac...

Good NVH is becoming must feature in recent commercial vehicles. One of the major discomforts caused to driver by Engine vibration during idling. The power train is suspended on the vehicle frame on several flexible mounts, whose purpose is to isolate the vibration between engine and frame. Total 6 different modes of Engine like roll, yaw, pitch and Vertical, lateral and longitudinal need to is...

This paper aims to present the newly designed acoustic emission AE instrument for the in-situ monitoring of corrosion damages of aircraft structures. The work was theoretically based on the combination of modal AE theory and AE parameter analysis technique. Previous research had shown that identification of corrosion AE and background noise by modal acoustic emission(MAE) technique was possible...

In addition, simulation has become usual practice aimed at solving problems associated with vibro-acoustic control for several categories of products ([1] to [5]). This approach is indeed less expensive and time consuming in comparison with the experimental one. It does not need the actual implementation of noise treatments and carrying on extensive field measurements. Moreover, it allows the p...

In operational modal analysis process of the rotating machinery, it is always difficult to adopt usual modal analysis methods in parameter correction because of the modal parameter identification problems caused by harmonic modes. A technique to distinguish harmonic and structural modes is proposed here, that is, through frequency domain decomposition (FDD) of the vibration signals power spectr...

This study focuses on investigation of the method of identifying injector faults in a JCB 444T2 diesel engine using acoustic emission (AE) technique. Different kinds of injector faults were seeded in the four-cylinder, four-stroke, and turbo-engine. Then, faulty injectors are tested to evaluate AE based injection fault detection. The AE signals recorded from the tests were processed in the angu...

OBJECTIVES The aim of the study was to assess the acoustic and capacity analyses of voice in academic teachers with hyperfunctional dysphonia using DiagnoScope Specialist software. MATERIAL AND METHODS The study covered 46 female academic teachers aged 34-48 years. The women were diagnosed with hyperfunctional dysphonia (with absence of organic pathologies). Having obtained the informed conse...