Mechanical, Morphological, Thermal and Dynamic Study of Composites of Unsaturated Polyesters-Date Palm Leaf Fiber DPLF

In order to improve the properties of unsaturated polyesters, this study discusses the possibilities of developing a natural waste, date palm leaf fiber DPLF, produced in the northern Algerian Sahara, associated with the polymer matrix of a thermosetting polyester resin UP. For this purpose, composite plates containing virgin fiber at rates of 6 and 10% were treated with an alkaline solution of 6% NaOH on the one hand, and a silane compound on the other. In this research, a mechanical study of strength and elongation at break was carried out. In addition, morphological behavior was followed by SEM scanning electron microscopy. ATG thermogravimetric analysis and energy flow were monitored by DSC differential scanning calorimetry. Also, a study of the water absorption capacity has been conducted. In addition, a dynamic mechanical analysis DMA was carried out. The findings of this study show that there is a favorable mechanical behavior for the composites containing the 6% and 10% DPLF fiber, with alkaline NaOH and Silane treatment. They also show that the chemical treatment with alkaline solution and silane gives composites certain thermal stability compared to those with untreated fiber. Findings also explore that the absorption of water by the various composites shows that the chemical treatment promotes some intermolecular associations with water. Findings also show that the storage modulus (E') increases when the composite contains 10% DPLF, treated and untreated, and the maximum value of the tangent moves towards the high temperature for the treated and untreated fiber composite.

Lattice Parameters, Electronic, and Magnetic Properties of Cubic Perovskite Oxides ARuO3 (A=Sr, Rb): A First‑Principles Study

Trioxides of rubidium, strontium, and ruthenium belong to the family of alkali and alkaline earth ruthenates. SrRuO3 crystallizes in various symmetry classes—orthorhombic, tetragonal, or cubic—whereas RbRuO3 is perovskite (cubic) structured and crystallizes only in the cubic space group Pm3¯¯¯m(No. 221). In this study, we investigated the structural stability as well as the electronic and magnetic properties of two cubic perovskites SrRuO3 and RbRuO3. We established the corresponding lattice parameters, magnetic moments, density of states (DOS), and band structures using ab‑initio density‑functional theory (DFT). Both compounds exhibited a metallic ferromagnetic ground state with lattice parameter values between 3.83 and 3.96 Å; RbRuO3 had magnetic moments between 0.29 and 0.34 µBwhereas SrRuO3 had magnetic moments between 1.33 and 1.66 µB. This study paves way for further RbRuO3 research.

A Comparison Between a Solid Block Made of Concrete and Others Made of Different Composite Materials

In this research, three mathematical models were designed, the first consisting of concrete, the second from carbon fiber, and the third from s-glass fiber, in order to compare the strength of composite materials to different stresses and deformations, because composite materials are better than concrete in terms of weight and shape and do not need to be applied to painting operations in addition to the fact that their thermal insulation is higher than Concrete in high proportions. From the results of the comparison, it was found that the second model was the best model in terms of bearing deformations, as the deformation percentage in it did not exceed the deformation of concrete a lot, reaching (17%), which is a very small percentage, and the stresses towards pregnancy for the second and third models were much better than the bearing of the first model, but the results indicate that the Von Mises Stress in the second model is higher than the first model by a percentage (57%), while the comparison of the third model with the first was the rate of increase percentage (47%).

Process Parameters Optimization for GMA Welding of AISI 1008 Steel Joints for Optimal Tensile Strength

Parameters optimization has become a gateway to achieving quality welds with improved properties desirable for construction and industrial applications. The complex interaction of welding input parameters requires process optimization to achieve optimal responses (s). This study reports the optimization of input parameters for Gas Metal Arc Welding (GMAW) for optimal ultimate tensile strength in AISI 1008 steel joints. Three levels of arc voltage, welding current, and gas flow rate were selected as input parameters, while the targeted output response is the ultimate tensile strength. Taguchi’s method with an L-9 orthogonal matrix was adopted for the process optimization. The MINITAB 17 software was used to analyze the response through analysis of variance and signal-to-noise ratio. The result revealed that the parameter settings for optimal tensile strength for the GMA welding of 6 mm thick AISI 1008 steel joint are arc voltage set at 30 V, current at 180 A, and gas flow rate set at 17 L/mm. The analysis of variance showed that the arc voltage had the most significant influence on the ultimate tensile strength with a 39.76% contribution, followed by the gas flow rate with 31.15%, while the welding current had 6.28% contributions. The surface plots show that a lower-level voltage, higher-level welding current, and higher-level gas flow rate favoured maximum ultimate tensile strength.

Comparison of the Wear Behavior and Hardness of Vinylester Resin Reinforced by Glass Fiber and Nano ZrO2 and Fe3O4

The current trend in scientific researches is to improve the performance of mechanical and physical properties of polymeric compounds, one of these methods is to add nanoparticles to polymeric composites. In this work, the wear behaviour (pin to disc) of nanocomposites composed of vinyl ester reinforced glass fibers and nanoparticles was evaluated under three different factors, such as specimen content, load applied, and distance sliding using a sliding time constant, as well as studying the hardness shore for these nanocomposites. The (hand-lay) method was used for the purpose of preparing the nanocomposites from vinyl ester filled with 10% vf. glass fiber and (0.5%, 1%, 1.5%, and 2% vf. of nano-Fe3O4 and ZrO2). The results are tabulated and analysed using Taguchi experiments (L9) (Minitab 18) for the purpose of determining which of the factors under consideration had the greatest influence on the wear behaviour. From the results, it was found that the specimens (vinyl ester-10% vf. glass fibers-2% ZrO2) and (vinyl ester-10% vf. glass fibers-2% Fe3O4) give the best wear resistance 0.003×10-5, 0.012×10-5 mm3/Nm respectively under the factors (load 20 N, sliding distance 45 cm). It was found that the specimen content is the most important factor influencing the wear behaviour, followed by the factors of the applied load and then the sliding distance. The addition of nanoparticles (0.5-2% vf. ZrO2, Fe3O4) to the vinyl ester resin improved the hardness values. Furthermore, the findings show that the addition of nanoparticles (ZrO2, Fe3O4) had a positive effect on the (wear and hardness) tests, implying that the nanoparticles improved the bonding between the base material and reinforcing material.

Modelling and FE Simulation of HVC Using Multi Objective Response Surface Optimization Techniques

The purpose of an automotive chassis is to maintain the shape of the vehicle and bear the various loads that are applied to the vehicle. The structure typically accounts for a large portion of the development and production costs of the new vehicle program, and the designer has many different structural concepts available. Choosing the best is important to ensure acceptable structural performance under other design constraints, such as cost, volume and method of production, product application, and more. The material selection for chassis depends upon various factors like lightness, economy, safety, recyclability, and circulation of life. The current study aims to perform optimization of the design of a heavy vehicle chassis using central composite design & optimal space fill design scheme (s) with the material tested is Al6092/SiC/17.5p MMC. Different design points are generated using design of experiments. The equivalent stress, deformation and mass are evaluated for each design points. The CAD modelling and FE simulation of heavy motor vehicle chassis is conducted using ANSYS software. From the optimization conducted on chassis design, response surface plots of equivalent stress, deformation and mass are generated which enabled to determine the range of dimensions for which these parameters are maximum or minimum. The use of Discontinuously Reinforced Aluminium-Matrix Composites Al6092/SiC/17.5p MMC aided to reduce weight of chassis by 66.25% and 66.68% by using CCD and Optimal space fill design scheme respectively, without much reduction in strength of chassis.

Viscoelastic Mechanical Model of Asphalt Concrete Considering the Influence of Characteristic Parameter of Fiber Content

This paper carries out bending creep tests on polyester fiber-reinforced asphalt concrete beams, and investigates how the volume ratio and aspect ratio of the fibers influence the parameters of viscoelastic mechanical model and the viscoelastic performance of the asphalt concrete. The results show that: with the growing volume ratio and aspect ratio of the fibers, the midspan deflection and bottom flexural-tensile strain of asphalt concrete beams first dropped and then rose over time; the characteristic parameter of fiber content (FCCP) could reflect the overall effects of the volume ratio and aspect ratio of the fibers. On this basis, a viscoelastic mechanical model was established for the asphalt concrete in the light of the influence of FCCP. The test and theoretical results show that, in our tests, the optimal volume ratio of fibers, optimal aspect ratio of fibers, and optimal FCCP are 0.348, 324, and 1.128 for polyester fiber-reinforced asphalt concrete.

Study of the Swelling of a Composite Based on Argan Nut, Urea-Formaldehyde and Water as a Non-Polluting Solvent

In the center and southwest of Morocco, there is an endemic tree «Argania Spinosa» known as the ironwood. The miraculous product of this millenary tree is argan oil. Known for its therapeutic and cosmetic properties. Only 20% of the fruit of the argan tree is intended for the manufacture of argan oil while the shell, which represents 80%, remains an unexploited resource. This hull, which is sold by farmers at low prices, is used as fuel for baths and Moorish bakeries. In order to value the shells; first, we sort, grind and sieve them. Second, we bind the particles into adhesive. Three biomaterials are based on three particle sizes of shell grains. The designed particles are bound with an adhesive powder that is produced from a pre-catalyzed urea-formaldehyde resin. Moreover, the water used is a non-polluting solvent. The biomaterials and two samples of Red and Beech Wood were immersed in water for 15 days, with mass measurements that were done on a daily basis. It was concluded that the swelling coefficient of the large distribution of biomaterial is smaller than the small distribution of biomaterial. However, Red and Beech Wood have the highest coefficient.

Performance Evaluation of Asphalt Binder Modified by Natural Rock Asphalt

Rock asphalt is one of the widely distributed resources in nature. Therefore, this study employs natural rock asphalt as an additive. The focus of this study is to look at the potential of using natural rock asphalt as an asphalt binder modifier. The study looks at five different percentages of modified asphalt (NRA) concentration from Anbar factory asphalt for oxidized bitumen: 0%, 5%, 10%, 20%, and 30%. The results show that using modified natural rock asphalt increased the mechanical qualities of basic asphalt, such as penetration and softening point, flash point, and viscosity. In addition, the current results show that the asphaltic materials that can be used in paving according to the measuring of conventional tests such as ductility, penetration, and others. Furthermore, the findings indicate that modified asphalt has lower temperature sensitivity.