Issue 67

S. Sahu et alii, Frattura ed Integrità Strutturale, 67 (2024) 12-23; DOI: 10.3221/IGF-ESIS.67.02



     b

    b b j ω t j ω t b e = f ω e

      - ω M +j ω D + K U ω 2 b b b b b

(4)

Shape functions perform an important role in solving the problems of dynamic analysis of cracked or faulty beams. The Shape functions refer to one of the displacements being equal to ‘1’ and all other displacements are taken as ‘0’. In the current research work Hermitian shape function is used.



 -1

  = - ω M +j ω D + K     2 b b b b b

 

(5)

 

 

H ω

b b

    b b X ω

      b b b f ω 

= H ω 

(6)





When the damping condition is neglected.

    1 2 b b b  

 



 

 

H ω

- ω M K

(7)

b b

Here BC -Before the appearance of crack AC -After the appearance of crack     2 b b b b H ω  

  -1 b

(8)

=- ω M + K





BC

BC

BC

  =- ω M + K 2 b b

  -1 b

 

 

 

(9)

H ω

b b

AC

AC

AC

  -1 2 b b + ω M

  b K = H ω  b b  

 

(10)



T

T

T

where the subscription ‘T’ represents the total stiffness matrix. We know that the mass matrix does not change during the process of crack generation. So, the change in stiffness can be written as follow,       -1 -1 BC AC Δ K = H - H (11) A PPLICATION OF AN IMMUNE BASED AI APPROACH FOR STRUCTURAL FAULT DETECTION Artificial Immune System (AIS) is an emerging field of heuristic evolutionary algorithm. It has been noticed that there is an increasing interest to design and develop of calculative models inspired by immunological principles and theory. Collective name of number of algorithms inspired by an immune system is known as Artificial Immune System (AIS). All the research within AIS in theoretical immunology and numerous parallel streams have also been conducted over the past two decades. This research results in development of distinct sub-streams like the computational immunology. In a disposition of computational and theoretical immunology lies at the core of Artificial Immune System (AIS). Within the S tructural health monitoring (SHM) consists of different assignments in the damage detection. One of the most important benefits of SHM is the damage identification before any severe catastrophic failure. Practical solution needs a large quantity of sensors and robust system for data analysis. In this case a bio-motivated method has been analyzed and described. The proposed technique includes identification of damage or any discontinuation and use of immune based technique for finding out the location of the damage. As SHM processes require continuous data processing algorithms to make a robust tool for a quick and efficient damage detection process. This work is used to first identify the discontinuation or development of any minute crack, then the use of Artificial Immune System (AIS) based method for designing the algorithm.

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