Spectral elements based on Legendre polynomials are used to improve an existing finite-element method for simulating a highly nonlinear field phenomenon: fluid cavitation in an underwater-shock environment. Further improvement is provided by separation of the total field into its equilibrium, incident, and scattered components. These enhancements promise to make the finite-element method suitab...

The implementation of high-order (spectral) approximations associated with FEM is an approach to overcome the difficulties encountered in the numerical analysis of complex problems. This paper proposes the use of the spectral finite element method, originally developed for computational fluid dynamics problems, to achieve improved solutions for these types of problems. Here, the interpolation n...

The magnetic flux leakage (MFL) method is currently the most commonly used pipeline inspection technique. In this paper, numerical simulation and experimental investigation on defect inspection in pipeline steel using MFL were carried out. In theoretical analysis, typical three-dimensional (3D) defects were accurately modeled and detailed MFL signals in the test surface were calculated by 3D fi...

Leakage fields are one of the main issues in design of electromagnetic systems. Some of these fields close their paths through the core and air, giving rise to non-ideal behavior of the magnetic systems. This paper explains a novel concept of active shielding which consists of two compensation coils in series and generates a counter field opposite to the leakage fields leaking from an iron-core...

In order to analyze the leakage magnetic field and stray loss in power transformer, leakage magnetic field and stray loss in structure parts of a power transformer are calculated by three-dimensional (3-D) non-linear time harmonic finite element method (FEM). The results show that stray loss and loss density in structure parts are large and which may lead to local overheating and affect perform...

in this study a series of ambient vibration tests on the triple ferrocement elevated water tanks with 150 cubic meters volume, is carried out. in order to verify the dynamic characteristics of full, half-full and one full tanks (mass eccentric system), the different arrangements of sensors are used. the effects of base rotation are also considered in the tests. natural frequencies and mode shap...

An efficient and modular numerical prediction model is presented to predict vibrations and re-radiated noise in buildings due to metro trains. The approach comprises of three weakly coupled problems: the dynamic vehicle-track-tunnel-soil interaction problem, the dynamic soil-structure interaction problem and the calculation of the acoustic response inside the rooms. The three-dimensional dynami...