Vibrations of launch vehicle conical fairings are investigated. Fairings simulated using thin conic shells. The modal analysis a elastic shell is based on the use developed finite element model an inhomogeneous shell. In general, technique makes it possible to investigate geometrically nonlinear deformation, stability, and post-buckling behavior wide class structure implemented at each step sta...

BACKGROUND Whole-body-vibrations are often associated with adverse health effect but the long term effects are less known. This study investigates the association between occupational exposures to whole-body vibrations, and subsequent transition to disability pension. METHODS A total of 4215 male employees were followed up for subsequent disability pension retirement. Exposure to whole-body-v...

We study theoretically two vibrating quantum emitters trapped near a one-dimensional waveguide and interacting with propagating photons. demonstrate, that in the regime of strong optomechanical interaction light-induced coupling emitter vibrations can lead to formation spatially localized vibration modes, exhibiting parity-time (PT ) symmetry breaking. These be interpreted as topological defect...

Arterial bleeding into a free space is known to cause local vibrations in tissue. To study the effectiveness of utilizing these tissue vibrations in localizing the site of arterial bleeding, we have developed an algorithm for ultrasonically imaging these tissue vibrations. Simulation results indicate that our algorithm can correctly detect vibrations in the presence of pulsatile wall motion, bl...

Flow induced vibrations are an important concern in the design of nuclear reactors. One of the possible designs of the 4th generation nuclear reactors is a lead-cooled fast reactor of which MYYRHA is a prototype. The combination of high liquid density, flow velocity, low pitch-todiameter ratio and the absence of grid spacers makes this design prone to flow induced vibrations. Although most vibr...

The purpose of introducing ultrasonic vibrations in the tube hydroforming process is to create more formability by obtaining a lower corner radius, improve thickness distribution of the wall and provide good tribological conditions at the tube and the die interface. Vibrations imposed on the die create alternating gaps which improve the formability in the tube hydroforming process in the presen...

The article presents resarches for designing and manufacturing of the ultrasonic motors that uses piezoceramic materials. There are presented specific vibrations modes for the studied piezoceramic plates, vibrations that are used to excite the motor activated element (mobile element). Using the finite element method it is really posssible to predict the usefull vibrations that can makes easier ...

a linear superposition method was used for modeling the time history of the production blast vibrations and optimizing the blast sequence to reduce vibration levels in sar-cheshmeh copper mine, kerman, iran. a single-hole blast for modeling and two double-hole blasts with time delays of 25 and 65 ms between two holes for modeling validation were carried out. the generated vibrations were measur...