Articles in This Issue
Abstract
Turning is the most popular machining operation. The quality of the product may be determined using a variety of metrics, such as the surface generation method and the surface roughness of the product. This work uses cutting variables to obtain the best surface quality through a mathematical model. The suggested surface generation in this work results from deriving it using the Bezier technique, with degree (5th) having six chosen control points. One of the critical indicators of the quality of machined components is the surface roughness created during the machining process. Surface roughness improvement via machining process parameter optimization has been extensively researched. The Taguchi Method and actual tests were employed for evaluating the surface quality of complicated forms; regression models with three different variables for the cutting process, such as cutting speed, depth of cut, and feed rate, were also used. According to the experimental findings, the most significant effect of feed rate on the surface roughness is approximately (40.9%), and the more minor effect of depth of cut on the surface roughness is almost (16.23%). In addition, the average percentage error is 4.93%, the maximum error is 0.14 mm, and the minimum error is -0.143 mm for the prediction using the regression equation.
Abstract
The Cross-Rolling (CR) process is a severe plastic deformation technique that was used to roll aluminum alloy 6061. However, this process is accompanied by many disadvantages, such as spring back due to elastic recovery. This research aims to investigate the effect of cross-rolling on the spring back phenomenon by examining the main parameters that affect the forming process. Two different routes of cross-rolling were used: the first route, called two-step cross-rolling (TSCR), and the second, multi-step cross-rolling (MSCR), were employed to achieve high deformation and superior mechanical properties. The samples were bent using the V-bending process at three different speeds (5, 10, and 15 mm/min). The results showed that the rolling route and the change in cutting direction led to increased plastic deformation, thus increasing the spring-back factor. The type of route and cutting direction significantly impacted both the maximum load and the springback results.
Abstract
This paper proposes an efficient algorithm for fast computation of the inverse real-valued discrete Fourier transform (IRDFT) using the decimation in frequency (DIF) approach. The proposed algorithm represents a direct method with a new implementation for fast computing of IRDFT. The algorithm derivation is based on the basic principles of the Cooley-Tukey algorithm with the divide and conquer approach and utilizes the advantage of conjugate symmetric property for the discrete Fourier transform (DFT) to remove all redundancies that appear when DFT deals with real data. The analyses of the proposed algorithm have shown that the arithmetic number has reached a minimum, therefore the structure of the developed algorithm possesses the desired properties such as regularity, simplicity, and in-place computation. The arithmetic complexity of this algorithm has been compared with the inverse FFT algorithm, and it was found that it needs the least number of multiplications and additions. The validity of the developed algorithm has been verified by reducing the peak-to-average power ratio PAPR in optical-OFDM systems compared with complex FFT. The simulation using MATLAB(R2021a) findings show that the RFFT O-OFDM system reduces PAPR more efficiently than the FFT O-OFDM system. The PAPR exhibits a reduction of approximately 2.4 to 2.75 dB when evaluated at a probability of occurrence of 10-1 in the complementary cumulative distribution function (CCDF) plot.
Abstract
Prefabricated schools are educational structures of great significance and utility, especially given our country's current challenges. They expedite construction, reduce environmental impacts, and enhance educational activities with strong structural integrity and comfortable, flexible, and healthy design. A compelling comparison can be made with traditional concrete schools. With advancements in technology and information in engineering and the construction industry, Building Information Modeling (BIM) technology has emerged, playing a vital role in prefabricated concrete engineering through 3D modeling simulations.Numerous challenges are encountered, such as meeting client requirements, project delays, cost overruns, quality issues, stakeholder conflicts, labor shortages, safety concerns, increased change orders, material wastage, and project complexity. Developed countries utilize BIM to mitigate these challenges and profoundly improve the AEC industry's performance. BIM tools provide a comprehensive building visualization, empowering stakeholders to make informed decisions that ensure efficiency, sustainability, and cost savings. These features motivate engineers and contractors to rely on them as essential engineering applications.This research involves modeling a school building in the Revit program, studying work flow between Revit and ETABS program, and conducting a dynamic analysis of the model from Revit. It also emphasizes the benefits of prefabricated construction and BIM technology, facilitated by Revit. The study emphasizes how important it is to visualize the building's actual form before beginning the design and decision-making processes.in summery, this study provides the possibility of growth and application in the industrialization of the construction industry and raise the project's overall quality. The development of tools and plugins programmed to reduce interoperability problems between various software packages allows for integrating all design activities.
Abstract
In this study, the water evaluation and planning WEAP model was used to improve the Fallujah irrigation project with 63,000 hectares and an annual budget get 1,476 million m3/ yiod (2020-2021). The results showed the total Water used was 1,272 million m3/year and equaled 86% of Fallujah irrigation budget. The annual production was 524.4 million Kg/year for Fallujah irrigation, and total economic returns were 393.6 million $/year. The study outlined two scenarios for enhancing the irrigation system. The first scenario entailed implementing a sprinkler irrigation system for wheat and barley across all projects. This resulted in a production increase from 524.4 to 625.7 million kilograms per year and a corresponding rise in economic returns from 393.6 to 427.2 million annually. In the second scenario, a sprinkler system was adopted for wheat and barley and a trickle system for other crops. This approach led to production growth from 524.4 to 1164.9 million kilograms per year and a surge in economic returns from 393.6 to 559.4 million annually.
Abstract
Problematic soils, especially clayey soil, are problematic for engineering projects in their natural state because of clay's swell-shrinkage phenomenon. Numerous methods and stabilizer materials have been used to enhance clay's geotechnical properties and make them appropriate for construction. One of the significant methods of stabilization of problematic soil is using waste materials like waste glass, waste stone, waste plastic, etc. Due to the waste stone's consistency reducing water content and increasing the soil's strength, it has been employed in many civil engineering studies. Waste stone is available in various forms, including waste stone powder (WSP). WSP is produced by blasting tunnels or cutting huge stone blocks. Hence, the main aim of this study is to review the influence of WSP on improving the geotechnical properties of problematic soils treated with WSP, for this purpose, the treated problematic soils with various percentages of WSP are compared with natural soils. This study evaluates physical properties (i.e., Index properties, linear shrinkage/swelling, optimum moisture content, and maximum dry density) and mechanical properties (i.e., unconfined compressive strength and California bearing ratio). Also, the effect of WSP on decreasing the thickness of pavement layers was reviewed
Abstract
Designing large structures like dams requires carefully selecting various geometric, hydraulic, and structural characteristics. The required structural design and performance criteria are considered when selecting these characteristics. In order to find the best solution, a variety of restrictions must simultaneously be carefully taken into account. This study presents an effective method for determining the optimal shape design for concrete buttress dams. The research was divided into two crucial phases. The dam's initial design and subsequent modeling were mostly done using DIANA FEA and traditional design and stability analysis. After that, a genetic algorithm was used on the MATLAB platform to control optimizing the dam's shape. Three design factors were used in this phase to alter the goal function and to reduce the amount of Concrete used, which decreased project costs. These variables covered three areas of the buttress's cross-section. Two important limitations were scrutinized during this optimization process: establishing a safety margin against overtopping and preventing sliding. The analysis included a detailed assessment of Shear friction stability to complete a thorough stability study. The optimization efforts had a spectacular result, resulting in a significant 52.365% reduction in the total volume of Concrete used, dropping from 19147.5 cubic meters to 9122.55 cubic meters. This decrease was made possible by reducing three distinct components (X1, X2, X3), with respective proportions of 37.5%, 13.33%, and 30%, including two segments related to the buttress and the final segment linked (slab) to the strip footing.