Experimental structural dynamic measurements are traditionally obtained using discrete sensors such as accelerometers, strain gauges, displacement transducers, etc... These techniques are known for providing measurements at discrete points. Also, a majority of these sensors require contact with the structure under test which may modify the dynamic response. In contrast, a few recently developed...

A method of complex orthogonal decomposition is applied to the extraction of modes from simulation data of multi-modal traveling waves in one-dimensional continua. The decomposition of a transient wave is performed on a nondispersive pulse. Complex wave modes are then extracted from a two-harmonic simulation of a dispersive medium. The wave frequencies and wave numbers are obtained by looking a...

This study examines the capability of various optimization algorithms and proposes novel hybrid for more precise prediction open-edge cracks in cantilever beams. The natural frequencies beam with a crack are obtained by modal analysis experimentally validated impact testing. performance Harris hawk (HHO), electrostatic discharge algorithm (ESDA), pathfinder (PFA) Henry gas solubility (HGSO) fro...

An approach is presented to investigate the 1:2 internal resonance of sling and beam a suspension sling–beam system. The was taken as geometrically linear Euler beam, considered be nonlinear. dynamic equilibrium equation structures derived using modal superposition method, D’Alembert principle Hamilton principle. nonlinear equations free vibration forced oscillation were solved by multiple-scal...

Abstract: The present paper concludes via an analytical method to reduced formulae for determining the eigenfrequencies and eigenmodes of multi-span continuous beams with spans of different lengths and bending rigidities in a very easy and efficient way. The rigorous determination of eigenfrequencies and eigenmodes allows us to focus on the derivation of the time function for the forced vibrati...

Adaptive control of a flexible continuous structure is investigated. The application is directed toward large sensor count and several actuator systems,(multiple input / multiple output (MIMO) control. Conventional large channel count control applications involve complicated techniques to determine the proper order of the model and the dominant modes to be controlled. Using spatial filtering to...

Cantilever beam is a simplified sample of a lot of mechanical components used in a wide range of applications, including many industries such as gas turbine blade. Due to the nature of the operating conditions, beams are subject to variety of damages especially crack propagates. Crack propagation may lead to catastrophic failure during operation. Therefore, online detection of crack presence an...

We report on efficient coherent addition of spatially incoherent multimode laser beam distributions. Such addition is demonstrated within a multi-channel laser resonator configuration, obtaining more than 90% combining efficiency while preserving the good beam quality. We explain the rather surprising physical phenomenon of coherently adding spatially incoherent light by self-phase-locking of e...