TEQIP Workshop on

Modal Analysis: Theory in Practice

Indian Institute of Technology Kanpur

17-21 September 2018

Course Content

  • Overview of modal analysis
  • Theoretical basis for modal analysis
    • Vibration of single and multiple degree of freedom (SDOF, MDOF) systems.
    • Frequency response functions (FRFs) for SDOF/MDOF systems. Types of FRFs.
    • Theory of undamped, proportionally damped, and non-proportionally damped SDOF/MDOF systems.
    • Orthogonality of modes and their application in modal analysis.
  • FRF measurement considerations
    • Introduction to test planning
    • Role of excitations signals and techniques. Discussions on measurement transducers
    • Discussions on aliasing, leakage, windowing, filtering and averaging
    • Revision of Fourier analysis and Fourier transforms
    • Calibration. Dealing with measurement noise and coherence
  • Modal parameter extraction and derivation of mathematical models
    • Preliminary checks of FRF data (spectrum, coherence, etc.)
    • Detection of modes - mode indicator functions
    • Extraction of modal parameters (natural frequencies, damping ratios and shapes) using frequency domain and time-domain methods
    • Reconstruction of spatial models from modal and response models
  • Experimental modal analysis
    • Laboratory sessions to demonstrate Chaldni patterns and calibration
    • Measure frequency response functions to investigate role of transducer mounting, check for reciprocity, and to investigate role of boundary conditions
    • Measurements using impact hammers and modal shakers
    • Measurements for modal parameter extraction
    • Measurements of real test structures such as machine tools, turbines etc.
  • Applications and advanced topics
    • Model correlation. Concepts of modal assurance criterion and its variants
    • Finite element model updating. Model reduction and expansion
    • Dynamic substructuring
    • Testing of weakly nonlinear structures

Contact Information

For question related to talks of the workshop:
Dr. Mohit Law

Dr. Shakti Gupta

For any other questions:
TEQIP Office
Knowledge Incubation for TEQIP, Indian Institute of Technology Kanpur