Course11210231846 lectures
Experimental Modal Analysis
Prof. Subodh V. Modak · IIT Delhi
About
This course is about the fundamentals and basic concepts of Experimental Modal Analysis (EMA) and its applications. EMA, also known as Modal Testing, is a technique for experimentally determining the natural frequencies, mode shapes, and damping factors of a physical system or structure. One primary application of EMA is for the avoidance of resonant operation and troubleshooting vibration and noise problems. Another important application is in validating and updating structural dynamic FE models. EMA also enables deriving an experimental mathematical model of a physical system, which can be used for response simulation, force identification, structural modification, and structural control. The course will start from the theoretical basis of EMA, followed by signal processing for modal analysis. Then it will cover how the frequency and impulse response functions (FRFs and IRFs) can be measured by exciting the structure and measuring the input force and output response and how the modal parameters can be estimated from these measured FRFs and IRFs. In the end, the course will briefly cover Phase resonance testing, Operational Modal Analysis, and applications of EMA.
Intended audience: • BE/B. Tech/ME/M. Tech/MS/PhD students of Mechanical, Aerospace, Automotive, Civil, and Naval architecture disciplines• Practicing engineers and professionals
Prerequisites: Basic mechanics
Lectures
Week 1
- Lecture 1 : Introduction
- Lecture 2 : Lumped parameter models of Vibrating systems
- Lecture 3 : SDOF Undamped system
- Lecture 4 : SDOF system with Viscous damping
- Lecture 5 : SDOF system with Structural damping
- Solved Examples Session 1
Week 2
- Lecture 6 : Modal analysis of MDOF Undamped system (Free vibration)
- Lecture 7 : Modal analysis of MDOF Undamped system (Forced vibration)
- Lecture 8 : Modal analysis of MDOF system with Structural damping
- Lecture 9 : Modal analysis of MDOF system with Proportional Viscous damping
- Lecture 10 : Modal analysis of MDOF system with Non-proportional Viscous damping
- Solved Examples Session 2
Week 3
- Lecture 11 : IRF and Transient resposne
- Lecture 12 : FRF Characteristics of SDOF systems
- Lecture 13 : FRF Characteristics of MDOF systems
- Solved Examples Session 3
Week 4
- Lecture 14 : Fourier series expansion
- Lecture 15 : Fourier Transform
- Lecture 16 : Discrete Fourier Series (DFS)
- Lecture 17 : Discrete Fourier Transform (DFT), DTFT, FFT
- Solved Examples Session 4
Week 5
- Lecture 18 : Aliasing, Quantization
- Lecture 19 : Windowing, Leakage, Window functions
- Solved Examples Session 5
Week 6
- Lecture 20 : Principle of Experimental Modal Analysis (EMA)
- Lecture 21 : Excitation using an impact hammer
- Lecture 22 : Response measurement, piezoelectric accelerometer
- Solved Examples Session 6
Week 7
- Lecture 23 : FRF estimation, H1 and H2, Coherence function
- Lecture 24 : Test planning for FRF Measurement
- Lecture 25 : FRF Measurement with an Impact hammer
Week 8
- Lecture 26 : Excitation using a Shaker
- Lecture 27 : FRF estimation with random excitation
- Lecture 28 : FRF measurement with ranodm excitation
- Lecture 29 : FRF measurement using Pseudo, Periodic and Burst random and sine chirp excitations
Week 9
- Lecture 30 : Modal Parameter Estimation - 1 (Peak picking method)
- Lecture 31 : Modal Parameter Estimation - 2 (Circle fit, Line fit)
- Lecture 32 : Modal Parameter Estimation - 3 (RFP)
- Lecture 33 : Modal Parameter Estimation - 4 (ERA, Stabilisation diagram)
Week 10
- Lecture 34 : Phase Resonance (Normal Mode) Testing, RMIF, MMIIF
- Lecture 35 : Operational Modal Analysis (OMA)
Week 11
- Lecture 36 : Incomplete model, Response simulation, Force identification
- Lecture 37 : Structural modification
Week 12
Syllabus and materials
At NPTEL, as the course publishes them.
Credits and licence
- Institution
- IIT Delhi
- Department
- Mechanical Engineering
- Teacher
- Prof. Subodh V. Modak
- Level
- Undergraduate
- Language
- English
- Subjects
- Engineering
- Source
- NPTEL
- Licence
- CC BY-NC-SA, as NPTEL states it. Non-commercial use only. NPTEL's terms
- Attribution
- NPTEL states: "Distributed under Creative Commons Attribution-ShareAlike / CC BY - NC - SA", beside a BY-NC-SA badge.
- Who can watch
- NPTEL gives no rating. Invisible Network shows it to Tweens profiles and older, judged from what the source says about it. How courses are placed