Showing 2 results for E. Esmailzadeh
E. Esmailzadeh and A. R. Ohadi,
Volume 17, Issue 1 (7-1998)
Abstract
The useful and efficient method of Finite Element (FEM) has a drawback for dynamic analysis of complex structures, especially in the medium and high frequency range. To overcome this fundamental difficulty, application of Statistical Energy Analysis (SEA) and power flow technique has been suggested. As the SEA is based on the average response of structure and statistical properties of its resonant modes, SEA is found to be effective in cases like high modal density, high modal overlap and in short wave length. In these cases, the average response is found to be both real and an acceptable value, contrary to the FEM which is not accurate enough.
In this study, the fundamental difficulties of FEM in the high frequency range are explained and then the advantages and applications of SEA and power flow technique are presented. Moreover, a description of SEA basis, fundamental concepts of General Energy Method (GEM) are explained and formulated to be used in the longitudinal and transversal vibrations of beams. Finally, by satisfying the energy boundary conditions, the energy flow analysis of rods and beams with elastic support and under harmonic excitation are investigated.
E. Esmailzadeh, H. R. Bahrampuri and N. Niksefat,
Volume 20, Issue 1 (7-2001)
Abstract
Articulated liquid cargo vehicles transporting inflammable fuels and dangerous chemical products require special consideration when traveling on urban roads or cruising at highway speeds. The road safety and handling of these kinds of vehicles may be adversely affected when negotiating sharp turns or travelling on slippery roads, which may result in either lateral instabilities or complete rollover of these tanker vehicles. Moreover, directional instabilities in these kinds of vehicle may also introduce an excessive yaw swing or may initiate the jack-
knifing of the articulated tanker trucks. In order to overcome the instabilities of these tanker vehicles, installation of lateral baffles in the form of separating walls in the tanker were considered. The static roll and yaw plane models of these vehicles including lateral translation of the liquid inside the tank were developed. Using the static roll model, the rollover threshold of the vehicle is analyzed and the effect of these separating walls on the stability of the vehicle is studied. The yaw plane model is then used to predict the transient response and stability of the tanker vehicle under various road maneuvers. The governing differential equations were solved numerically to obtain the simulation results and optimum values of the parameters.
Keywords: Tanker, Vehicle, Stability, vehicle dynamic, rollover, lateral baffles
