The Effects of Plate-Support Condition on Buckling Strength of Rectangular Perforated Plates under Linearly Varying In-Plane Normal Load
— Mechanical buckling analysis of rectangular plates with central circular cutout is performed in this paper. The finite-element method is used to study the effects of plate-support conditions, aspect ratio, and hole size on the mechanical buckling strength of the perforated plates subjected to linearly varying loading. Results show that increasing the hole size does not necessarily reduce the mechanical buckling strength of the perforated plates. It is also concluded that the clamped boundary condition increases the mechanical buckling strength of the perforated plates more than the simply-supported boundary condition and the free boundary conditions enhance the mechanical buckling strength of the perforated plates more effectively than the fixed boundary conditions. Furthermore, for the bending cases, the critical buckling load of perforated plates with free edges is less than perforated plates with fixed edges.
Elastic stability of pierced square plates
The Ritz energy method is employed for the determination of the critical edge displacement of a simply supported square plate with a circular central hole subjected to uniform edge displacements. Displacement functions assumed for the three components of middle surface displacements are studied for hole diameters varying up to three-tenths of the plate dimension. The importance of singular terms is investigated and an approximate conversion is made from critical displacements to critical loads. The experimentally determined buckling load, defined as the inflection point on the load-deflection curve, verifies the theoretical predictions.
Simulation and control of hybrid renewable energy system connected to the grid
This paper presents a control and simulation of hybrid renewable energy system connected to the grid. The studied system includes a photovoltaic panel, synchronous permanent magnet generator based wind turbine, and a battery for storage energy. The PV array and wind systems are connected to the common DC bus by a boost converter. The battery is connected by a bi-directional DC/DC converter, and then integrated into the AC utility grid via a common DC/AC inverter. In order to extract the maximum energy, a simulation study has been carried out according to the meteorological conditions (wind speed and variable solar irradiance) while maintaining power quality at a satisfactory level. In order to capture the maximum power, a MPPT algorithm is applied for both wind turbine and photovoltaic panel. The modeling and simulation of the whole system has been performed under Matlab/Simulink environment. The obtained results show that the current and the voltage of grid side are sinusoidal and alternative forms, and the power injected to the grid is around the power produced by the hybrid system.