Effect Of Shape Geometry Research Articles

Determination of the General Formula to Estimate the Discharge Quantity of Composite Structure for Free Flow

River and open channel flow measurement is regarded as an important element in improving water system management. An experimental analysis in a laboratory flume has been executed to obtain formulas which can be used to predict the discharge quantity which crosses over the sharp crested weir and under the gate in the composite structure which is a tool of flow measurement. These formulas are applied for the free flow condition. Different configurations of composite structure have been used. These configurations have regular and irregular shapes. The derivation of the discharge quantity equation is based on the dimensional analysis which is employed to analyze the factors that control the operation of the composite structure. The family of formulas consists of eight formulas that are divided into two groups. The first group consists of four formulas which are derived based on the variable that dominates the hydraulic behavior of the composite structure, while the second group consists of four formulas based on the same variables of the first group but taking into consideration the effect of weir and gate shape by adopting the hydraulic radius of weir and gate. Based on the evaluation process, all formulas can be used perfectly well to predict the discharge quantity, regardless of the shape of weir and gate. On the other hand, based on the validation process, the formula that considered the effects of shape geometry, flow and fluid properties has given the best prediction of the discharge quantity.

Effect of shape geometry on electromagnetic radiation under quasi-static compression in sintered aluminium preforms

This paper presents the effect of shape geometry on electromagnetic radiation (EMR) emissions from sintered aluminium preforms during deformation under unrestricted quasi-static compression. The EMR emissions under compression show shape anisotropy. The end surface conditions of the compressing platens, i.e. lubrication, also influence the EMR emission characteristics. The first EMR emission invariably occurs near the yield. The dead metal zones formed on the top and bottom portions of the specimens during axial compression, possibly generate a climbing motion of edge dislocations in the radially outward mid-regions. These edge dislocations form accelerated electric line dipoles and emit electromagnetic radiation during the climbing motion. These results appear significant in understanding the mechanism of plastic deformation in metal powder preforms at the microscopic level and are expected to give a deeper insight into the metal forming processes.

An experimental study on unbonded circular fiber reinforced elastomeric bearings

Seismic base isolation by introducing a flexible horizontal layer at the foundation level of a structure has proven to reduce the seismic demand. Steel reinforced elastomeric bearings have been used for that purpose extensively in the last years. More recently, innovative fiber reinforced elastomeric devices have been investigated as they bring important advantages as reduction of manufacturing and transport costs. The current article analyzes relevant mechanical properties for seismic isolation such as vertical and horizontal stiffness as well as damping capacity in fiber reinforced elastomeric bearings, focusing on the effect of shape geometry and material of the fiber reinforcement layers. Quasi-static cyclic experiments under vertical and combined horizontal and vertical load have been performed in order to investigate the effect of compression, horizontal deflection, frequency of the load and geometrical parameters. Compressive loads up to 12 MPa have been investigated. Moreover, the performance of bearings with round and square plan geometry under multidirectional loading is examined. Comparisons between the obtained results and data from previous works are discussed.