scholarly journals Natural Frequencies of Tapered Beam with a Crack and Crack Identification using Genetic Algorithm.

2001 ◽  
Vol 67 (657) ◽  
pp. 1366-1372
Author(s):  
Tadashi HORIBE ◽  
Naoki ASANO ◽  
Hiroyuki OKAMURA
Keyword(s):  
Genetic Algorithm ◽  
Natural Frequencies ◽  
Crack Identification ◽  
Tapered Beam

scholarly journals ANALYSIS AND PREDICTION OF MULTIPLE-CRACKED PLASTIC BEAM

2009 ◽  
Vol 12 (18) ◽  
pp. 37-45
Author(s):  
Hang Xuan Le ◽  
Luong Thi Hien Nguyen
Keyword(s):  
Genetic Algorithm ◽  
Cantilever Beam ◽  
Stiffness Matrix ◽  
Natural Frequencies ◽  
Fitness Function ◽  
High Accuracy ◽  
Crack Identification ◽  
Element Stiffness Matrix ◽  
Crack Location ◽  
Local Flexibility

This paper presents a method for identification of location and depth of a crack in a cantilever beam by means of a genetic algorithm based on the signs of crack identification are beams natural frequencies. The cracked element stiffness matrix is based on the theory that local flexibility goes up because of the appearance of cracks. Crack location and depth is identified by minimizing fitness function, which performs difference between natural frequencies calculated and measured. Results show that this method helps to make prediction with high accuracy and converging speed.

scholarly journals Out-of-Plane Vibration of Curved Uniform and Tapered Beams with Additional Mass

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Hamdi Alper Özyiğit ◽  
Mehmet Yetmez ◽  
Utku Uzun
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Boundary Conditions ◽  
Natural Frequencies ◽  
Variable Cross ◽  
Additional Mass ◽  
Inertia Effects ◽  
Tapered Beam ◽  
Out Of Plane ◽  
Good Agreement

As there is a gap in literature about out-of-plane vibrations of curved and variable cross-sectioned beams, the aim of this study is to analyze the free out-of-plane vibrations of curved beams which are symmetrically and nonsymmetrically tapered. Out-of-plane free vibration of curved uniform and tapered beams with additional mass is also investigated. Finite element method is used for all analyses. Curvature type is assumed to be circular. For the different boundary conditions, natural frequencies of both symmetrical and unsymmetrical tapered beams are given together with that of uniform tapered beam. Bending, torsional, and rotary inertia effects are considered with respect to no-shear effect. Variations of natural frequencies with additional mass and the mass location are examined. Results are given in tabular form. It is concluded that (i) for the uniform tapered beam there is a good agreement between the results of this study and that of literature and (ii) for the symmetrical curved tapered beam there is also a good agreement between the results of this study and that of a finite element model by using MSC.Marc. Results of out-of-plane free vibration of symmetrically tapered beams for specified boundary conditions are addressed.

scholarly journals Multiple crack identification in stepped beam by measurements of natural frequencies

2014 ◽  
Vol 36 (2) ◽  
pp. 119-132
Author(s):  
Nguyen Tien Khiem ◽  
Duong The Hung ◽  
Vu Thi An Ninh
Keyword(s):  
Crack Detection ◽  
Natural Frequencies ◽  
Rayleigh Quotient ◽  
Crack Identification ◽  
Multiple Cracks ◽  
Simple Relationship ◽  
Multiple Crack ◽  
Scanning Method ◽  
New Approach ◽  
Efficient Procedure

A new approach is proposed for calculating natural frequencies and crack detection in a stepped cantilever beam with arbitrary number of cracks. This is based an explicit expression of the natural frequencies in term of crack parameter derived in the form similar to the so-called Rayleigh quotient for vibrating beam. The obtained simple relationship between natural frequencies and crack parameters enables not only accurate calculating the natural frequencies but also to develop an efficient procedure for detecting multiple cracks from given natural frequencies. The proposed technique called crack scanning method is illustrated and validated by numerical results.

A Pareto-Based Genetic Algorithm Search Approach to Handle Damped Natural Frequency Constraints in Turbo Generator Rotor System Design

2004 ◽  
Vol 126 (3) ◽  
pp. 619-625 ◽  
Author(s):  
Anders Angantyr ◽  
Jan Olov Aidanpa¨a¨
Keyword(s):  
Genetic Algorithm ◽  
Natural Frequencies ◽  
Design Criterion ◽  
Rotor System ◽  
Design Tool ◽  
Generator Rotor ◽  
System A ◽  
Turbo Generator ◽  
Design Variables ◽  
Search Approach

The detailed design of a turbo generator rotor system is highly constrained by feasible regions for the damped natural frequencies of the system. A major problem for the designer is to find a solution that fulfills the design criterion for the damped natural frequencies. The bearings and some geometrical variables of the rotor are used as the primary design variables in order to achieve a feasible design. This paper presents an alternative approach to search for feasible designs. The design problem is formulated as an optimization problem and a genetic algorithm (GA) is used to search for feasible designs. Then, the problem is extended to include another objective (i.e., multiobjective optimization) to show the potential of using the optimization formulation and a Pareto-based GA in this rotordynamic application. The results show that the presented approach is promising as an engineering design tool.

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