Minimization of the stress concentration in Formed Parts through Non-Parametric Optimization

Parametric and non-parametric are the main optimization methods that are used in various industrial fields. In non-parametric optimization, the process of manipulating the node locations (shape optimization) or removing mass without changing the node locations (topology optimization) is adopted to achieve a desired objective. This structural optimization is formulated as a non-parametric problem, and for analysis purposes, ABAQUS/CAE software is adopted for this approach. Manufacturing process like forming is always linked with stress concentration, especially in the sharp ends and variable cross sections like holes and fillets. The problems of representation and finding the optimal and better structural design of some known quantities such as reactions, loads and masses is not easy. A large deflection may be induced in a structure when experiencing severe mechanical loads. In this work, the numerical method has been presented to investigate a method for optimization of formed parts geometry. Numerical examination confirmed that high-stress concentrations are generated in many places. Material distribution is highly influenced by nonlinearity and the new layout will result in intermediate densities. In such cases, the nonlinear elasticity like nonlinear strain must be considered. As a result, the non-parametric optimization can offer good design flexibility to use the existing model with ease of setup and without the need for parameterization. It can provide a conceptual design that can reduce the structure's weight to the maximum extent in the early design stage. This work is going to optimize the design of the formed plates by reducing the volume while maximizing its stiffness. As a recommendation, in order to provide an attractive approach with suitable levels of structural performance, the combination of both optimization methods is the short way to achieve this aim

Mechanical and Thermal Properties of Polyurethane-Palm Fronds Ash Composites

The aim of the article is to study the influence of environmentally friendly palm frond ash on the mechanical and thermal properties of polyurethane used as filler. Various weight filler ratios with particle sizes around (125 μm) were examined and characterized using elongation, tensile strength, Young's modulus, compressive strength, average burning time, and infrared spectroscopy. The results showed that the addition of 20 wt.% palm frond ash powder significantly improved the hardness mixture by about 2.83 MPa. In addition to that, the highest value of the compressive strength of the polymer with the additive was recorded at 10 wt.%. Also, the most excellent value of Young’s modulus was 2 MPa at a ratio of 50 wt. %, as was the average burning time of about 33 sec. The mechanical properties of polyurethane were affected by adding palm frond ash, which increases the tensile and compressive strengths, making it suitable for use in many applications. Moreover, the environmentally friendly material reflects the benefits of waste recycling. The addition of filler affects the morphology and strengthens the brittleness. Additionally, the use of fly ash from palm frond combustion in the technology of polyurethane materials complies. Partial replacement of petrochemical components with waste filler also reduces the total energy consumption in producing PU composites. &nbsp

A Review of Parameters and Mechanisms in Spray Cooling

Miniaturisation in avionics, electronics, and medical appliances has led to demands for rapid heat dissipation techniques. The spray cooling technique has gained importance recently due to its advantage over other cooling methods. Parameters affecting heat transfer mechanisms during spray cooling are contemplated. This review presents different heat transfer parameters and their effect on spray cooling by analysis from past studies. Heat transfer surface modifications and different coolant variations to enhance heat transfer effectiveness are also reviewed. Apart from high heat flux having more applications, low heat flux studies have also grabbed the researchers to find solutions with a temperature range lower than 250˚C. Therefore, the upcoming spray cooling technology will have broad applications that will contribute to the maximum efficiency of the heat removal rate

New smart actuator based on shape memory alloys for avoiding overheating and preventing fire in electronic devices

In the past few years, fire incidents in electronic systems have become frequent and caused many losses of life and property. Consequently, various studies have been conducted in order to establish effective ways to avoid fire caused by electrical devices. In light of the fact that electrical sensors frequently get damaged, it is crucial to develop a smart switch that can detect and control off electrical current during an unexpected heat increase or fire incident. In this study, a numerical study that aims to develop a smart actuators combined with electrical devices in order to protect electronic system from fire accidents has been conducted. The proposed smart actuator is based on the shape memory alloy (SMA), which has a robust thermomechanical coupling that reacts to the temperature variation and generates an important mechanical loading. Using the SMA actuator between an electrical power source and the device will avoid any incident related to the temperature increase. Therefore, mathematical modelling has been conducted to adjust the smart actuator with any electrical device, with rules that will be developed to increase the actual detection rate. The simulation results of the proposed fire detection system has been compared with several current methods. The results show that the proposed engineering is very promising and can respond to a temperature change in 0.2 s and generate a total deformation of about 8%. The results show that the suggested method has a higher fire detection rate that can reach 90% for detection

Review Of Grain Refinement Performance Of Aluminium Cast Alloys

Improving the utilization of aluminum grain refinement in industrial settings is a continual point of focus for research. Grain refinement serves the dual purpose of not only achieving a fine grain size, but also enhancing the mechanical properties of materials. Numerous researchers have dedicated significant efforts over the last decades to explore the grain refinement of aluminium alloys. There have been a number of studies relating to the mechanisms that explains the observed phenomena associated with grain refinement. The most commonly employed are grain refiners based on Al–Ti–B system. However, a limited efficiency of these grain refiners on aluminium silicon alloys with excessive Si and the effect of alloying elements have been noticed. The review examines the impact of the factors influencing grain refining behaviour of master alloys, including the effects of poisoning elements such as Si, Mg, Zr, and Sr. A large grain refiners used for enhancing the properties of aluminium silicon alloys are reviewed. An overview of new refiners has been given. Also, procedures for assessment of grain refinement have been examined.  &nbsp

Research on Treating Demineralized Enamel with Different Remineralizing Agents before Bonding Orthodontic Brackets

Many orthodontic clinics have problems with patients who have dental demineralization. This study aimed to evaluate “the shear bond strength (SBS)” of braces after being bonded to demineralized teeth treated with herbal materials. Our study samples were divided into five groups. The first group was left with no treatment. The surfaces of the second, third, and fourth groups were first treated with a demineralizing solution. The second group was left after being demineralized without any subsequent treatment; the third group was treated with rosemary oil; the fourth was treated with ginger–honey. Casein phosphopeptide–amorphous calcium phosphate with fluoride paste (CPP–ACPF) was applied to the fifth group. A universal testing machine evaluated the SBS. A stereomicroscope was used to determine the adhesive remnant index (ARI). The enamel surface changes were observed using surface microhardness (SMH) testing, scanning electron microscopy (SEM), and energy dispersive spectrometry (EDS) to determine the element percentages. Our data revealed that the values of both SBS and SMH were significantly (p < 0.05) increased after remineralization. Rosemary and ginger–honey significantly enhanced the SBS and SMH of the demineralized teeth

Recycling of Magnesium Alloy Scrap by Remelting and Chemical De-coating Process

The growing demands of magnesium (Mg) based materials had risen new challenges related to disposal of unused parts and a huge amount of waste made by such metals. Attempts to recycle the scrap of these materials through remelting had become one of the preferred choices. However, a series of preliminary steps should be carried out to reduce the impurities as well as to maintain the quality of the casted ingot, for instance, by applying de-coating for removing paints or coating substrates at the scrap surface prior to remelting. In this research, the effects of chemical reagent de-coating on the properties of ingot obtained from recycling Mg scrap were studied. A commercial paint removal liquid was preferred as the reagent for removing paint layers over the Mg scrap surface. The de-coated scrap was then remelted in a conventional furnace with NaCl powder as the fluxing layer. The results of this study noticed the importance of chemical de-coating process to reduce the impurity contents in the ingot which might be originated from the coating or paint substrates covering the Mg scrap. Meanwhile, the density and hardness of the Mg ingot processed without de-coating were obviously higher than that had been cleaned previously with paint removing agent

Utilizing Homer Power Optimization Software for A Techno-Economic Feasibility, Study of a Sustainable Grid-Connected Design for Urban Electricity in, Khartoum

HOMER (Hybrid Optimization of Multiple Electric Renewable) streamlines the design of distributed generation (DG) systems for a variety of grid-connected and off-grid applications. In Sudan, it is difficult to acquire an effective photovoltaic array for residential use due to a lack of energy consumption in power generation and access to technological, social, and environmental constraints. A model of a low-energy, solar-powered house that is suitable for Sudanese social and economic norms requires a high-quality architectural design. Method Using the HOMER software, the charge advantage analysis of a hybrid system was studied and assessed using the value for each kilowatt of grid-connected systems or utility grid. The simulation results have been presented as the most efficient and cost-effective method for achieving various home counts. At the current price, the hybrid system has a refund term of about fifty-four years. If turbine prices in Khartoum decline, the overall cost of energy will be reduced

In Situ Production of B4C and FeV Enriched Composite Surface on Low Carbon Steel by Cast Sintering Technique

A simple and cost effective technique to obtain locally hardened composite layer on cast alloy was previously developed based on advantages of liquid-sintering theory. This methodology provides an opportunity to produce final product with hardened composite layer with good wear resistance during casting process. The current study investigated the effect of combined B4C and FeV substrates on the composite layer properties during in situ cast sintering technique for low carbon steel. Microstructure inspection, XRD phase analysis, chemical composition, thickness measurement and the hardness test on the produced composite layer were conducted. The technique produced up to 640 (±300) µm thick composite layer with maximum hardness of 481 (± 14.6) HV. The hardness of the reinforced surface layer is 3-4 times higher than the base alloy. The increased hardness of composite zone is directly attributed to the presence of the iron boron (FeB), boron vanadium (V2B3) and iron carbide (Fe3C). There were no significant effect of substrate composition on the produced thickness of the composite layer. However, an increase of FeV proportion in the powder mixture leads increased the hardness. The current study is a first attempt to produce locally hardened surface layer on the low carbon steel using simple and cost effective in situ technique with use of relatively inexpensive substrates.&nbsp

Maturity level of predictive maintenance application in small and medium-sized industries: Case of Morocco

In order to remain competitive in the long term and to push the company's efficiency to its limits, entrepreneurs are more and more open to the idea of integrating into Industry 4.0 aiming mainly at filling the important downtimes and the associated productivity losses by implementing predictive maintenance. This concept, common in developed countries, is much less widespread in Morocco and even less in small and medium-sized Moroccan companies. The objective of this article is to study the maturity level of predictive maintenance in Moroccan small and medium-sized enterprises, through a questionnaire validated by experts and made available to several companies. Valid data from 115 companies throughout the kingdom operating in different sectors were collected and processed by descriptive and factorial analysis under SPSS software. The results obtained show that only 33% of our sample were able to implement predictive maintenance, and that the expected benefits of this approach are the minimization of downtime at 96.5% and the increase in productivity at 94.8%, The main challenges observed are the lack of team motivation and a corporate culture unsuited to digitalization, which represents 42.277% of the total variance, lack of financial resources at 12.916% of the total variance and lack of data protection at 11.644% of the total variance. This analysis indicates that the level of maturity regarding the application of predictive maintenance in Moroccan small and medium-sized companies is low, these rates can be used to improve the root causes