Development of the next generation of space flight vehicles has prompted a renewed focus on sound source characterization and near-field propagation modeling. Without advancements in these areas, large uncertainties in vibroacoustic loading estimates on space vehicles and payloads may result in structural designs that are either insufficient or excessive. Improved measurements in an extreme env...

A sub-structuring vibroacoustic approach is proposed to systematically deal with the difficulties and complexities involved in the modeling and optimization problem of duct silencers with complex internal partitions. The mixed separation of rigid/flexible structure with allowed air aperture between coupled acoustic domains is modeled as a compound structural interface, which greatly simplifies ...

Virtual auditory environments (VAE) are becoming more and more important for the development phase of vehicles. Interactive simulation introduces a quite new dimension in comparison to laboratory listening tests. In order to achieve an immersive VAE, all relevant sound components have to be realized in a realistic way and updated in real-time according to the driver’s actions. A concept is pres...

The transient acoustic dynamics of a splash cymbal are investigated via the Finite Element Method-Boundary Method. Real three-dimensional motion data recorded from interaction drummer–drumstick–cymbal provide initial and loading conditions to simulated drumstick–cymbal Models. Progressively intensified free strokes used as for both experiment simulation. velocity values moving drumstick in vari...

Purpose: The conduction of experimental studies in the conditions locomotive depot, transition to mathematical modeling wheel-motor block for diagnostics position, not allowing disassembly, traction electric motor bearings. Methods: Diagnostic complexes determine technical state depots. In order approaches choice and evaluation power source parameters vibroacoustic blocks depot analysis designi...

The exploration of electromagnetic vibration sources is very important for the vibroacoustic reduction a squirrel-cage induction motor. However, influence high-order force on motor has not been studied before. investigated in detail. Firstly, Maxwell stress tensor method applied to calculate force. Next, transfer function introduced describe phenomenon that induces low-mode vibration. Then, for...

Elevation in placental corticotropin-releasing hormone (pCRH) during the last trimester of pregnancy has been associated with an increased risk for preterm delivery. Less is known about the consequences for the human fetus exposed to high levels of pCRH early in pregnancy. pCRH levels were measured in 138 pregnant women at least once at 15, 20 and 25 weeks of gestation. At 25 weeks of gestation...

Vibroacoustic disease (VAD) is a systemic disease that results from long-term exposure to low-frequency noise (LFN). VAD can cause lesions in several organs. Noise-exposed individuals frequently present digestive symptoms, but only a few studies have attempted to evaluate gastrointestinal lesions. The aim of this study was to investigate the duodenal alterations in VAD, using an animal model of...

the aim of this investigation is to compare the effect of applying two transcutaneous electrical nerve stimulation (tens) current with different frequencies (2 hz & 100 hz) on hoffmann reflex recorded from gastrosoleus muscle of healthy people. forty female subjects between 20 to 30 years of age were participated in this quasi-experimental design. twenty of them were exposed to the 100 hz curre...