changes in dynamic properties of structures indicate occurrence of damages in the structures. in this paper, a new two stage algorithm for damage detection of large structure is introduced. a modified residual force method is utilized to locate the damage regions in structures, especially barrel vaults, and then the enhanced charged system search (css) algorithm is used to quantify the amount o...

The vibro-acoustic behavior of systems and components in modern vehicles play an increasingly important role in the development process of high quality products in automotive industry. In order to characterize the numerous mechanical, electrical and mechatronic systems, many of which embody significant sources of structure-borne sound and vibration, advanced measurement techniques are required....

Modal-based acoustoelastic formulation is regarded as the cornerstone of vibro-acoustics and has been widely used for coupling analyses of structure-cavity systems. The controversy and the skepticism surrounding the acoustic velocity continuity with the surrounding vibrating structures have been persistent, calling for a systematic investigation and clarification. This fundamental issue of sign...

A direct conversion modulator-demodulator with even harmonic mixers with emphasis on noise analysis is presented. The circuits consist of even harmonic mixers (EHMs) realized with antiparallel diode pairs (APDPs). We evaluate the different levels of I/Q imbalances and DC offsets and use signal space concepts to analyze the bit error rate (BER) of the proposed transceiver using M-ary QAM schemes...

A novel resonant metamaterial solution is designed and applied to a vehicle in order reduce the structure-borne noise interior compartment due first acoustic tyre resonances around 230 Hz. This control consists of metal 3D printed elements rear wheel arches as potential alternative commonly used dynamic damper solutions, which are typically installed on suspension or body case severe issue. The...

In the first International Operational Modal Analysis Conference it was shown for the first time how transmissibility measurements can be used to identify modal parameters. The main advantage of this new technique is that it is no longer necessary to make the assumption that the inputs to the structure are white noise. The unknown operational forces can be arbitrary (colored noise, swept sine, ...

According to the great importance of safety in aerospace industries, identification of dynamic parameters of related equipment by experimental tests in operating conditions has been in focus. Due to the existence of noise sources in these conditions the probability of fault occurrence may increases. This study investigates the effects of noise in the process of modal parameters identification b...