26/06/2017 |

Modal Analysis Laboratory

Purpose of the Laboratory:

The dynamic analysis of structures is one of the requirements for their design and maintenance. Today, two separate tools are used to model the dynamic behavior of the structures, namely numerical tools and experimental ones. The most widely used numerical tool is the Finite Element (FE) method, while the experimental counterparts are largely based on modal testing and analysis. The FE method is extensively used in industry as it can produce a good representation of a true structure. However, for complicated structures, due to the errors in the details of geometry, material properties and boundary conditions, an FE model can lead to errors. Unlike, Vibration measurements are taken directly from a physical structure, without any assumptions about the structure, and that is the reason that modal testing models are considered to be more reliable than Finite Element models.

Therefore, the aim of this laboratory is utilizing and integrating the analytical and experimental modal data for modelling the dynamic behaviour of structures. In recent years, to accomplish these goals, some research and industrial projects have been performed in this laboratory.

List of some Research Projects:

  • Optimal design of a damped vibration absorber using genetic algorithm
  • Damage identification from uniform load surface using continuous and stationary wavelet transforms
  • FRF-based model updating using SMURF technique
  • A hybrid frequency response function formulation for MDOF nonlinear systems
  • Identification of modal parameters using enhanced frequency response function
  • Fault detection of rolling bearings using vibration analysis
  • Determination of mode shapes using wavelet transform of free vibration data
  • Vibration absorber design via frequency response function measurements
  • Estimation of rigid body properties from the results of operational modal analysis
  • Estimation of rigid body inertia properties from modal testing results
  • Scaling of mode shapes using mass-stiffness change method
  • Identification of closely spaced modes using Ibrahim time domain method
  • Estimation of modal parameters for structurally damped systems using wavelet transform

List of some Industrial Projects:

  • Identification of natural frequencies and damping ratios of turbine vanes
  • Double modes determination of a gearbox shaft
  • Identification of natural frequencies and damping ratios of nano-composite materials
  • Modal parameter identification of Crankshaft of a vehicle
  • Modal parameter identification of a Karting car-chassis

List of some Equipment:

  • Data Analyzer B&K
  • Power Amplifier B&K
  • vibration exciter B&K
  • Impact Hammer B&K
  • Measuring Amplifier B&K
  • Laser Doppler Vibrometer
  • VibroTest 60, SCHENCK
  • Force Transducer, Piezoelectric Accelerometer