Fluidelastic instability of a single flexible cylinder subject to fluid cross flow has been investigated in arrays of rigid tubes arranged in a normal triangular configuration with pitch ratios of and . The test facility designed and built for this purpose has two novel features: (i) the flexible tube is supported by a linear structure which allows only pure translation of the tube in a directi...

This paper provides an overview of methods that examine changes in measured vibration response to detect, locate, and characterize damage in structural and mechanical systems. The basic idea behind this technology is that modal parameters (notably frequencies, mode shapes, and modal damping) are functions of the physical properties of the structure (mass, damping, and stiffness). Therefore, cha...

Non-Obstructive Particle Damping (NOPD) technology is a passive vibration damping approach whereby metallic or non-metallic particles in spherical or irregular shapes, of heavy or light consistency, and even liquid particles are placed inside cavities or attached to structures by an appropriate means at strategic locations, to absorb vibration energy. The objective of the work described herein ...

An easy-to-implement method to measure relevant elastic and damping properties of the constituents of a sandwich structure, possibly with a heterogeneous core, is proposed. The method makes use of a one-point dynamical measurement on a thick plate. The hysteretic model for each (possibly orthotropic) constituent is written generically as “E(1 + jη)” for all mechanical parameters. The estimation...

This study deals with an application of the proper orthogonal decomposition (POD) method to a simplified structural dynamic system with local known non-linearities. The POD method is applied to experimental and simulated time-series data, in order to extract modes that efficiently represent the system. The ability of these modes to detect and identify structural non-linear behaviours is then in...

Health monitoring of engineering structures has gained a lot of interest over the last few years. Many engineering structures suffer damage and deterioration when exposed to various loading and environmental changes during their lifetime. This seriously affects structural performance and may even lead to catastrophic structural failures. Thus, inspection and testing of structural components for...

This paper describes dynamic analysis using proposed fast finite element method for a shock absorbing structure including a sponge. The structure is supported by nonlinear concentrated springs. The restoring force of the spring has cubic nonlinearity and linear hysteresis damping. To calculate damping properties for the structures including elastic body and porous body, displacement vectors as ...

The modal characterization of automotive lighting systems becomes difficult using sensors due to the light weight of the elements which compose the component as well as the intricate access to allocate them. In experimental modal analysis, high speed 3D digital image correlation (HS 3D-DIC) is attracting the attention since it provides full-field contactless measurements of 3D displacements as ...

Modal sound synthesis has been used to create realistic sounds from rigid-body objects, but requires accurate real-world material parameters. These material parameters can be estimated from recorded sounds of an impacted object, but external factors can interfere with accurate parameter estimation. We present a novel technique for estimating the damping parameters of materials from recorded imp...

Damping plays a key role in dynamic response prediction, vibration control. Following the brief description of ambient vibration testing and measurements, three nonparametric damping estimation approaches for engineering structures are introduced: (1) time domain approach using Data Correlation (DC); (2) time-frequency analysis via Wavelet Transform (WT), and (3) a spatial domain approach based...