Coursework

1. TERM PAPER
PRESENTATION ON
“Vibration Based Damage Detection Technique”
Presented by:
UMAR SHAHAB KARIMI
Roll No. 19PHDCE026
Under Supervision of:
PROF. KHALID MOIN
Department of Civil Engineering
Faculty of Engineering & Technology
Jamia Millia Islamia University

2. Introduction
 Detection of structural damage from vibration data has become very popular topic of research.
The reason behind rise in popularity is aging infrastructures.
 Day by day, there is rise in traffic and its loading. Increased volume of traffic is now unable to
meet the earlier design standard. Consequently, increased traffic loading accelerates structural
fatigue. This leads to reduced service life of the structure. Considering this, the frequency of
inspection must increase to counteract reduction in safety of these structures.
 For many years people have been performing vibration tests on large civil engineering structures.
The dynamic characteristics of the structures contain useful information about its state. Therefore,
vibration testing can be considered as a non-destructive health monitoring technique.
Existence of structural damage in an engineering system leads to modification in the vibration
modes. These modifications are reflected as change in modal parameters like mode shapes,
natural frequencies. These can be obtained from the results of vibration tests.

3. Continued…
Most of the damage detection methods use natural frequency, mode shapes, stiffness or
flexibility matrices as the identification parameters.
 The basic principle of damage detection methods is to compare the structural behavior in the
damaged state with structural behavior in undamaged state.
 To detect location of damage in the structure and amount of damage, it is important to
characterize the undamaged structure.
 Recent advances in computer, sensors and other electronic technologies has made vibration
based damage detection more convenient and cost effective than destructive detection
techniques.
 Damage in the structure can be linear or non-linear.

4. Objective
The aim of this term paper is to know and understand the detection of damages induced in
structure due to vibration.
Within this aim the specific objectives are:
i. To conduct a literature review on damage detection in structures through vibration.
ii. To conclude about applications and limitations of vibration based damage detection in
structures.

5. Literature Review
Amirabbas Haidarpur and Kong Fah Tee (2020)
 It used model updating approach to detect, locate and characterize damage in structural
systems by observing changes in vibration responses.
 Changes in physical properties such as mass, damping and stiffness caused changes in
modal properties like natural frequencies, mode shapes, etc.
 It characterized different methods on the basis of level of damage detection provided from
vibration testing. Modal properties are then obtained using modal analysis techniques.
John James Moughty and Joan Ramon Casas (2016)
 Due to degradation in the structural components, structural condition of bridges decline
gradually. There is uncertainty regarding stability of structures.
 In traditional method of vibration based damage detection technique only changes in modal
parameters were focused. Such methods were unable to distinguish damage due
environmental and operational factors from structural one. Also they were time consuming.
 Recent advance researches in this field are able to assess complex data and higher noise
level.

6. Literature Review
This paper discussed different state of the art developments in this field for detecting damage
in small to medium span bridges and it particularly focuses on more advanced computational
methods.
Tai Ping Chang (2015)
 Dynamic interaction system between vehicle and bridge was established on a bridge model.
It was characterized as composite laminated beam. Discretization of laminated beam was
done by finite beam element method.
 Damage identification using dynamic response of bridge in damaged state was taken as
input data.
 A sensitivity matrix was developed using response sensitivity matrix with respect to indices
in damaged state.
 This sensitivity matrix was solved by using difference of errors between measured response
and computed response with the help of least square method.
 Then location of damage and amount of damage was determined using finite element
model updating technique.

7. Literature Review
NIU Jie et. al. (2015)
 They proposed a method for damage detection in girder bridge structures. It was based on
response surface model (RSM) updating and element model strain energy (EMSE).
 Effectiveness of this method was validated by performing beam model experiment on four
simply supported steel beams.
 It also employed real bridge simulation and testing to verify the proposed method.
Dora Foti (2013)
 In this paper two different experimental techniques for predicting damage location and
severity have been considered i.e. Mode Shapes Method and the Mode Shapes Curvature
Method.
 The techniques was applied to a simply supported finite element bridge model in which
damage was simulated by reducing the flexural stiffness EI.
 Results showed that a change in modal curvature is a significant damage indicator

8. Literature Review
Bart Peters et. al. (2001)
 Dynamic characteristics such as mode shapes, eigenfrequencies, damping ratio were
measured and impact of these characteristics due to excitation sources and effect of
temperature were discussed.
 Excitation sources and temperature are important parameters that may reduce damage
detection potential.
 Firstly, different types of excitation sources are compared like band limited noise that are
generated by shakers, effect of weight dropped. Also, effect of ambient sources are
considered.
 Secondly, a methodology was proposed to distinguish damage effect of temperature from
damage due to vibration.

9. Literature Review
O. S. Salawu (1997)
 It used natural frequency as a diagnostic parameter in structural assessment procedures
using vibration monitoring.
 The approach was based on the fact that natural frequencies are sensitive indicators of
structural integrity. Therefore, analysis of frequency measurements can be used to assess
structural condition.
 This approach can provide economical assessment of structural integrity.
 It also discussed various methods for detecting damage using natural frequencies and
limitations in successful application of vibration monitoring to damage detection and
structural assessment.
 Factors which could limit successful application of vibration monitoring to damage
detection and structural assessment were also discussed.

10. Conclusion
 It was noted that only one measurement point is required to detect damage in the
structure.
 Absolute damage of any beam element is well identified by using either the displacement
response, velocity response or acceleration response.
 The identified damage using the responses from either of the three measurement points
is very close to the real value.
 Excitation due to ambient sources such as wind, traffic, etc. generated comparable
results to the use of shakers.
 In case of intermittent monitoring, use of drop weight can be considered, as it is
economical, fast and easy to install.
 In case of continuous monitoring excitation due to ambient sources can be used.
 It can efficiently identify damage locations and amount of damage due to cracking as well
as bearing.
 There is no consensus among researchers as which particular method is most suited for
detecting damage through vibration.

11. References
 Haidarpour, A., & Kong, F. T. (2020). Finite Element Model Updating for Structural Health
Monitoring. Structural Durability & Health Monitoring, 14(1), 1.
 Moughty, J. J., & Casas, J. R. (2016, July). Vibration based damage detection techniques for
small to medium span bridges: A review and case study. In Proceedings of the 8th European
Workshop on Structural Health Monitoring (EWSHM 2016), Bilbao, Spain (pp. 5-8).
 Chang, T. P. (2015). 1679. Structural identification of damages on a simplified bridge model
in vehicle-bridge system from measured dynamic responses and sensitivity analysis.
 Niu, J., Zong, Z., & Chu, F. (2015). Damage identification method of girder bridges based on
finite element model updating and modal strain energy. Science China Technological
Sciences, 58(4), 701-711.
 Foti, D. (2013). Dynamic identification techniques to numerically detect the structural
damage. The Open Construction and Building Technology Journal, 7(1).

12. References
 Salawu, O. S. (1997). Detection of structural damage through changes in frequency: a
review. Engineering structures, 19(9), 718-723.
 Peeters, B., Maeck, J., & De Roeck, G. (2001). Vibration-based damage detection in civil
engineering: excitation sources and temperature effects. Smart materials and
Structures, 10(3), 518.

13. Thank You