scholarly journals A Pilot Fortran Software Library for the Solution of Laplace’s Equation by the Boundary Element Method

Author(s):  
Stephen Kirkup ◽  
Javad Yazdani
2011 ◽  
Vol 462-463 ◽  
pp. 1267-1272
Author(s):  
M. Safuadi ◽  
M. Ridha ◽  
Syifaul Huzni ◽  
Syarizal Fonna ◽  
Ahmad Kamal Ariffin ◽  
...  

In this paper, combination of a boundary element formulation and genetic algorithm (GA) was developed and used for analyzing of cathodic protection systems of buried pipe-lines structures. It is very important to maintain the effectiveness of the cathodic protection system for pipeline structure, in order to lengthen the lifetime of the system. However, nowadays the evaluation of the effectiveness of the system only could be performed after the system applying in the field. This study was conducted to combine 2D boundary element method (BEM) and GA in order to evaluate the effectiveness of the cathodic protection system for pipe-lines structure using ribbon sacrificial anode. Two factors i.e. the soil conductivity and the distance between pipe-lines and anode, were analyzed by using the proposed method. In this method, the potential in the domain was modeled by Laplace’s equation. The anode and cathode areas were represented by polarization curves of different metals. Boundary element method was applied to solve the Laplace’s equation to obtain any potential and current density in the whole surface of the pipe. The pipe and anode were modeled into 2D model. The numerical analysis result shows that the optimum distance between pipe-lines and anode can be determined by combining BEM and GA.


2011 ◽  
Vol 339 ◽  
pp. 171-175 ◽  
Author(s):  
Syarizal Fonna ◽  
M. Ridha ◽  
Syifaul Huzni ◽  
Israr Israr ◽  
Ahmad Kamal Ariffin

Boundary element inverse analysis (BEIA) by using genetic algorithm (GA) to identify corrosion location has been introduced by many researchers. However, the BEIA using GA is more complex to be programmed since it involved with genetic operators such as crossover and mutation. Recently, Particle Swarm Optimization (PSO) already takes researcher’s attention because of its simplicity to be programmed and comparable accuracy. This study is conducted to develop BEIA by combining Boundary Element Method (BEM) and PSO to identify the corrosion location of the steels in concrete structure from some potential data on concrete surface. The potential in the concrete domain was modeled by Laplace’s equation. The anode and cathode are represented by each polarization curve. The inverse problem is carried out by means of minimizing a cost function i.e. a difference between the calculated and measured potentials on the concrete surface. The calculated values of potential are obtained by solving the Laplace’s equation using boundary element method (BEM). Numerical simulation results show that the developed BEIA has proven that it can identify the corrosion location on the surface of reinforcement steel precisely.


2013 ◽  
Vol 686 ◽  
pp. 261-265 ◽  
Author(s):  
M. Ihsan ◽  
Syarizal Fonna ◽  
M. Ridha ◽  
Syifaul Huzni ◽  
A.K. Arrifin

The corrosion of structures is needed to be identified early to prevent any severe damage of buildings. The conventional technique such as potential mapping for diagnosing of reinforced concrete corrosion has been used widely in the field. However, the method has limitation such as less accuracy, laborious and time-consuming. This study is conducted to develop boundary element method 3 dimensions by considering polarization curves of anode and cathode for corrosion simulation and analyzed the influences of anode profiles for RC corrosion simulation. In this method, the potential in concrete domain was modeled by Laplace’s equation. The anode and cathode areas were represented by each polarization curves. The numerical simulation result shows that the boundary element method 3 dimensions successfully solved the Laplace’s equation in order to simulate corrosion phenomenon of reinforced concrete. The influences of anode profiles for RC corrosion simulation have been analyzed. Further works are needed to reduce the computational effort of corrosion simulation.


2019 ◽  
Vol 9 (8) ◽  
pp. 1642 ◽  
Author(s):  
Kirkup

The boundary element method (BEM) in the context of acoustics or Helmholtz problems is reviewed in this paper. The basis of the BEM is initially developed for Laplace’s equation. The boundary integral equation formulations for the standard interior and exterior acoustic problems are stated and the boundary element methods are derived through collocation. It is shown how interior modal analysis can be carried out via the boundary element method. Further extensions in the BEM in acoustics are also reviewed, including half-space problems and modelling the acoustic field surrounding thin screens. Current research in linking the boundary element method to other methods in order to solve coupled vibro-acoustic and aero-acoustic problems and methods for solving inverse problems via the BEM are surveyed. Applications of the BEM in each area of acoustics are referenced. The computational complexity of the problem is considered and methods for improving its general efficiency are reviewed. The significant maintenance issues of the standard exterior acoustic solution are considered, in particular the weighting parameter in combined formulations such as Burton and Miller’s equation. The commonality of the integral operators across formulations and hence the potential for development of a software library approach is emphasised.


1995 ◽  
Vol 5 (6) ◽  
pp. 621-638 ◽  
Author(s):  
J. H. Hilbing ◽  
Stephen D. Heister ◽  
C. A. Spangler

1993 ◽  
Vol 21 (2) ◽  
pp. 66-90 ◽  
Author(s):  
Y. Nakajima ◽  
Y. Inoue ◽  
H. Ogawa

Abstract Road traffic noise needs to be reduced, because traffic volume is increasing every year. The noise generated from a tire is becoming one of the dominant sources in the total traffic noise because the engine noise is constantly being reduced by the vehicle manufacturers. Although the acoustic intensity measurement technology has been enhanced by the recent developments in digital measurement techniques, repetitive measurements are necessary to find effective ways for noise control. Hence, a simulation method to predict generated noise is required to replace the time-consuming experiments. The boundary element method (BEM) is applied to predict the acoustic radiation caused by the vibration of a tire sidewall and a tire noise prediction system is developed. The BEM requires the geometry and the modal characteristics of a tire which are provided by an experiment or the finite element method (FEM). Since the finite element procedure is applied to the prediction of modal characteristics in a tire noise prediction system, the acoustic pressure can be predicted without any measurements. Furthermore, the acoustic contribution analysis obtained from the post-processing of the predicted results is very helpful to know where and how the design change affects the acoustic radiation. The predictability of this system is verified by measurements and the acoustic contribution analysis is applied to tire noise control.


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