Papers by Keyword: Orientation

Abstract: Even though the descriptive definition of orientation is the same in both settings, the explicitnotation of a crystallographic orientation as (3 3) matrix in terms of Euler angles featuredby the popular MATLAB toolbox MTEX differs by an inversion from the quasi-standard notation datedback to the early days of quantitative texture analysis championed by H.-J. Bunge. The origin of thisdiscrepancy is revealed by an enlightening view provided in algebraic terms of a change of basis.Understanding the effect of inversion is instrumental to do proper computations with crystallographicorientations and rotations, e.g. when multiplying with elements of a crystallographic symmetry group,and to compare results of texture analyses accomplished in different settings.

Abstract: In recent years, the whole world has been ailed by the change in climate with global warming and its negative effects on Earth’s climate system. Increased emissions and amplified energy consumption have resulted in a remarkable rise across the various climatic regions of Egypt, intensifying the thermal stresses on building facades. So to address this matter through a quantitative study, how climate change influences energy consumption rates will be analysed by referring back to the ECEEE records and Egypt's weather data files. The weather data files follow the seven climate regions and the different cities, starting with Alexandria, then Cairo, Minya, Asyut, Hurghada, Kharga, and finally Aswan. Based on the ECEEE records, each climate region has a particular thermal resistance (R-value) regulated by its zone location and weather conditions, thereby regulating consumption and reducing energy consumption. The simulations will also compare the most recent weather data files for 2021 with the original from 2006 in order to determine whether they are still applicable to today's energy depletion rates. The DesignBuilder program will be used to examine and compare R-values for an air-conditioned office space (6x4) m with a southwest orientation between 2006 and 2021. The results show an increase in Delta and Cairo Regions (2) by 50% , South Upper Egypt Regions (4) by 57% , and East Coast Regions (5) by 43% that were treated with XPS Extruded Polystyrene - CO2 Blowing as an insulation material addition, with its thickness adjusted according to the different regions. Keywords Climate Change, Energy Consumption, R-Value, Energy Code, Climatic Regions, Office Space, Orientation, Software Simulation, Envelope

Abstract: This research work aims to perform a comparative study on the effect of fiber orientation distribution (FOD) on the mechanical properties of composite laminates for aircraft and automobile structure. The objective of this project works is to use an analysis method to study the effect of significant parameters namely, with and without orientation on the glass fibre epoxy composites. The experimental work is used to investigate the mechanical behavior and to examine the properties with respect to fibre orientation on the composite laminates. The glass fibre orientation characteristics for the composite laminates is considered since they affect the strength of the specimen laminates. In this connection, the specimens were fabricated with different orientations and undergone for mechanical testing like tensile, compression and impact tests with Data Acquisition System. The experimental results indicate that the specimens with orientation provide more strength, high stiffness and good toughness than the normal specimens without orientation.

Abstract: This work is concerned the tensile properties of the secondary Ni-based single-crystal superalloy DD6 near [001] orientation at 760°C. In this study, anisotropic tensile properties of DD6 alloy within 10° of the [001] orientation were exhibited at 760°C. The yield strength and ultimate tensile strength of DD6 alloy oriented close to [001] direction was the highest. As the deviation off the [001] orientation increased, both 0.2% yield strength and ultimate tensile strength was decreased. The specimens oriented close to [001]-[111] boundary exhibit higher yield strength and ultimate tensile strength than the specimens oriented close to [001]-[011] boundary. Numerous of dislocations can be found in the γ matrix channels during the tensile deformation. A number of dislocation pairs and few of stacking faults are found in the γ' precipitates after the tensile at 760°C. The morphology of γ' phases in DD6 alloy maintained cubical during the tensile deformation at 760°C. With Schmid's Law, the mechanism of anisotropic tensile properties in DD6 alloy near [001] orientation is analyzed.

Abstract: Fiber reinforcement is widely used in construction engineering to improve the mechanical properties of concrete such as compressive and tensile strengths. Concrete is strong in compression but weak in tension and is a brittle material. In the construction industry, strength, durability and cost are among the major factors for selecting the suitable construction materials. During this investigation, the mechanical properties of sisal fibers reinforced concrete (SFRC) were assessed namely, flexural strength, tensile strength ad interfacial bond strength. The said properties were assessed in two types of reinforcement namely, randomly oriented sisal fibers and parallel oriented sisal fibers reinforcement. In both cases the sisal fibers were varied in volume fractions so as to establish the optimum value. The mechanical properties of flexural and tensile strengths were found to increase considerably with increasing fiber volume fractions until an optimum volume fraction is reached, thereafter, the strengths were found to decrease continuously. The prominent increment of 32.4% in flexural strength at fiber volume fraction of 2.0% parallel reinforced fiber concrete composite was observed. There was very small increment on both flexural and tensile strength for randomly oriented chopped sisal fibers reinforced concrete (SFRC). The Interfacial bond strength was found to be 0.12 N/mm² and was observed to be prominent for chopped sisal fibers reinforced concrete specimens tested for flexural strength. During failure, fiber pull-out was observed and the composite was observed to behave in a ductile manner whereby the fibers were able to carry more load while full fracture had occurred on the specimen. The water absorption capacity of the SFRC was found to increase with increasing sisal fiber volume fraction.

Abstract: Simple figures illustrate the basic concepts: orientation, Euler angles, Euler space, orientation density function, pole density function. The iteration that decisively influenced the development of orientation analysis follows directly from the relationship between the two density functions. The minimum principle defines the initial function and the structure of the iteration. Using model orientation density function, we prove that this kind of orientation analysis is extremely effective.

Abstract: Given the share of buildings in energy demand, improving the energy efficiency of buildings in Morocco is an important source of energy savings. In order to finally get surplus energy balance buildings to maintain a stable indoor temperature, this work investigated the influence of orientation and local building materials with and without insulation on energy needs of a building in the city of Errachidia using the ECOTECT ANALYSIS 2011 software dedicated to the Thermal Simulation of Buildings.

Abstract: In this work, an attempt is made to find out the difference in erosion resistance of bidirectional (fibre orientation in 0° and 90° only) and multidirectional (fibre orientation in 0°, 15° 30°, 45°, 60°, 75°, and 90°) glass fibre epoxy composites. The erosion rate of the composites at different sand impingement angles (30°, 45°, 60°, and 90°) and at different velocities (86.57m/s, 101.15m/s, and 119.2m/s) was observed. The maximum erosion rate was observed at 45° sand impingement angle for both bidirectional and multidirectional composites. The orientation of the fibre in the composite has very little significance on the erosion rate. Both the composites with unidirectional and bidirectional glass fibre showed semi ductile behaviour. SEM was used to examine the surface of the specimen subjected to erosion. Erosion tendency with impact angle and fibre orientation was also touched upon in the study.

Abstract: Components of gas turbines must be extremely resistant to high temperatures, high stresses, high-temperature corrosion, and erosive environments. The materials used in these environmental conditions are mainly nickel-based superalloys. In this study, the low-cycle fatigue of the nickel-based superalloy Inconel 792 was examined. The total strain range of a gas turbine between 760 °C and 870 °C was considered as the parameter representing the actual gas turbine operation. In addition, tests were performed using a trapezoidal waveform of the total strain to reflect the operation-stop conditions of a gas turbine with frequent shutdowns. The results of the fatigue test were compared with the Coffin–Manson method and energy method. The fractured surface was analyzed using a scanning electron microscope (SEM).

Abstract: Dibenzylidene Sorbitol is a very effective clarification additive for isotactic polypropylene. It is not effective with polyethylene although recent studies have shown that it can act as an effective nucleating and directing agent. We employ small-angle neutron scattering measurements to more fully understand the behavior of dibenzylidene sorbitol in a polyethylene matrix. The small-aangle neutron scattering clearly shows that the disappearance of the DBS fibrils is concentration dependent and for 2% DBS the midpoint of the dissolution is at 145°C and for 1% is ~ 20°C lower