Modal parameter analysis is a common method for structural characteristic analysis. To accurately identify the modal parameters that describe vibration characteristics of structure, chassis frame rice transplanter taken as research object. The least squares complex frequency domain method, admittance circle and peak picking are used to process measured signal. parameters, such natural frequency...

The main purpose of this paper is concerned with the sensitivity analysis of main rotor dynamic response pertaining to variation of some relevant system parameters effectively supports the preliminary design of both articulated and hingeless helicopter rotor configurations. The methodology is laid out based on Galerkin solution of partial differential equation (PDE) of main rotor with flexible ...

Abstract Task-based language teaching is considered an effective way to achieve a harmony between grammar and communication. The present study investigates two different ways of teaching modal verbs: task-based versus traditional approaches. To this purpose, an Oxford Placement Test was administered to select 40 homogeneous participants out of a larger population who took this test. The selecte...

A full-scale seven-story reinforced concrete building section/slice was tested on the NEES shake table at the University of California San Diego during the period of October 2005 to January 2006. Three output-only system identification methods were used to extract the modal parameters (natural frequencies, damping ratios, and mode shapes) of the test structure at different damage states. In thi...

-The performance of dynamic property of the mount is influenced by multiple factors and strongly depends on the working conditions. This means that the modal parameters of powertrain mounting system would make changes under different operating conditions. A novel approach to simulate the actual working condition is proposed in the testing of dynamic stiffness. Then the mechanical model of power...

This paper reviews the theoretical principles of subspace system identification as applied to the problem of estimating black-box state-space models of support-excited structures (e.g., structures exposed to earthquakes). The work distinguishes itself from past studies by providing readers with a powerful geometric interpretation of subspace operations that relates directly to theoretical struc...

Nowadays, the accurate identification of natural frequencies and damping ratios play an important role in smart civil engineering, since they can be used for seismic design, vibration control, and condition assessment, among others. To achieve it in practical way, it is required to instrument the structure and apply techniques which are able to deal with noise-corrupted and non-linear signals, ...