The present work aims to investigate the effect of an edge crack on the stress concentration around the circular hole surrounded by Functionally Graded Material (FGM) in an infinite plate subjected to uniaxial tensile load. The numerical investigation has been carried out using Extended Finite Element Method (XFEM). Two cases have been analysed in this work, i.e. the whole plate made up of radial FGM and homogeneous material plate having radial FGM layer around the hole. Young’s modulus of FGM varies according to exponential and power law function. The relations of stress intensity factor (SIF) and stress concentration factor (SCF) with normalised crack length, Young’s modulus ratio, FGM layer thickness and power law index have been presented. It has been observed that the FGM layer case has low SCF around hole than FGM plate case in presence of an edge crack.

The number of types of wire welding that circulate on the market and the development of welding technology, especially related to current welding, create a lack of information related to the quality of welding results for several types of materials. This can cause the strength of the welding connection to not be maximized. Therefore, this study aims to optimize the use of three types of wire welding and three current welding on the strength of the welding connection in two types of material testing using the response surface methodology. Box-Behnken, coupled with the RSM and the desirability function, was used to optimize the strength of the welding connection of the wire types (RD-46, LB-52, and RB-26), and current welding (100, 130, and 160 A) against two types of material testing (IWF-150 and ASTM-A517-G70). The strength of the welding connection observed in response included the tensile strength, Charpy impact-absorbed energy, hardness values in the welding metal and the hardness values in the main metal. Optimization of the strength of the welding connection in this study recommends the application of wire types RB-26, current welding of 100 A, and ASTM-A517-G70 material testing with the highest desirability value of 71.6%. Optimization of tensile strength, Charpy impact-absorbed energy, hardness values in welding metal, and hardness values in main metal by applying this parameter are 575.64 MPa, 110.69 J, 216.75 (HV10) and 126.6 (HV10), respectively. The results proved that an appropriate welding connection strength could be achieved using wire welding types and current welding in material testing.

In this article, hyperelastic material models that state consistent polynomial expansions of the stored energy function are discussed. The approach follows from the multiplicative decomposition of the deformation gradient. Some advantages of the third-order expansion model over the five-parameter Rivlin model using Treloar’s experimental data are shown. The models are qualitatively and quantitatively compared to highlight these advantages of the discussed model.

This study presents data on the development and research of cryogenic-vibration grinding process modes which would ensure an efficient grinding process of complex composite systems with a high degree of heterogeneity of components in their composition of products such as fluoroplast, bismuth oxide and tungsten carbide. The general regularities of low-temperature processing and grinding of non-degassed elastomers are established. A method has been tested that establishes the regularities of cryogenic grinding and ultrasonic homogenization of a complex mechanical system, the microstructure and dispersed compositions of the ground material have been determined.

The beam-column joints are designed to have sufficient capacity under earthquake loads. This requirement needs design details of reinforcement that fulfill the seismic criteria and adequate compaction of concrete. Using Self Compacting Concrete (SCC) material can solve the difficulty of compacting conventional concrete due to the close reinforcement distance. This study aimed to analyze the behavior of the Exterior Beam-column Joints (EBJ) using SCC as materials with a variation of shear reinforcements to withstand cyclic lateral loads. The analysis was carried out using the ANSYS software and the Finite Element Method. The analysis included hysteresis curves, stress contours, ductility, stiffness, and structural strength. The performance of an EBJ without shear reinforcement (EBJ-S1 model) was compared to other EBJs using horizontal (EBJ-S2 model) and diagonal (EBJ-S3 model) shear reinforcements in the joint zones. The results showed that horizontal and diagonal shear reinforcement in the joint zones affected the performance of the EBJs in resisting cyclic lateral loads as the representative of earthquake loads. The EBJ without shear reinforcement could withstand compressive stresses of 3.33 to 17.22 MPa, while both EBJs using horizontal and diagonal shear reinforcement achieved the same compressive stresses range of 3.33 to 20 MPa. The EBJ with diagonal reinforcement performed a wider compressive area of stress contour than the EBJ of horizontal reinforcement. The EBJ-S3 model achieved the highest ductility value of 4.733 with diagonal shear reinforcements because it achieved the highest ultimate displacement of the other EBJ models.

Peru is a country with plenty of renewable energy sources. However, its power demand depends on more than 50% of fossil fuels. Specifically, the power coming from the sun only represents 1% of the Peruvian energy matrix even though the territory has high radiation indexes. Therefore, the current analysis aims to search for the research situation of photovoltaic energy. Hence, this research looked for literature from RENATI and EBSCO, which provided 398 pieces of academic investigation. After applying the Prisma methodology to select the most relevant thesis and papers, we analyzed 48 elements. We found that the on-grid technology was the most viable in economic terms for projects related to business and electrification. At the same time, off-grid systems have been preferred for sanitation applications. Nonetheless, all the reviewed literature showed that photovoltaic technology positively impacted the environment and was as effective as conventional sources.

The corner point singularity of surface cracks by finite element method (FEM) has become a numerical concern decades ago. The literature showed that the stress intensity factors (SIFs) at the corner points were often excluded. Further, most SIFs were reported for larger ratios of the crack depth over cylinder diameter. This paper presents the SIFs (Modes I, II and III) of a semi-elliptical surface crack at a solid round bar under torsion. The tetrahedral and hexahedral elements were used in the finite element modelling. The effects of the loading mode and the crack aspect ratio on the corner point singularity were discussed. The tetrahedral meshing was generally observed to be more suitable for modelling relatively small surface cracks, particularly in respect to the corner point singularity. For all loading modes, the SIFs away from the corner points of using the tetrahedral meshing were found to have fairly good agreement with those by dual boundary element method (DBEM).

This study reports the flow stress behavior of three P92 steels with different compositions. Uniaxial compression tests were conducted in the deformation temperature range of 575 °C to 650 °C and strain rate range of 0.001-0.5 s-1 using a Gleeble® 3500 thermo-mechanical simulator. A simple physically-based constitutive model was used to analyse the effects of deformation conditions (temperature and strain rate) on the metal flow stress behavior during the deformation process. The method accounts for the temperature dependence of Young’s modulus and the lattice self-diffusion coefficient of Fe in the ferrite. Constitutive equations describing the flow stress behavior of the three P92 steels were developed. From the results, the stress exponent n of 26.13(steel A), 21.61(steel B) and 27.55 (steel C) were obtained using the self-diffusion activation energy in the physically-based constitutive equation. From the results, the three steels had variation in the stress exponent values, which was attributed to differences in elemental content, such as chromium and tungsten. The developed constitutive equations were verified using statistical parameters: Pearson’s correlation coefficient (R) and average absolute relative errors (AARE). Statistical analysis showed that the three steels had the same R of 0.98, while AARE was: 1.68 (steel A), 1.72 (steel B), and 1.82 (steel C). The constitutive equations developed showed a good correlation between the experimental and predicted flow stress data. Hence, the method is applicable in describing flow stress behavior in the metalworking process in the industry.

This paper presents a study of the solar dome system that is considered as one of the most important economical solutions in the domain of drinking water production. For this, a mathematical model was built from equations describing the optical and thermal phenomenon involved in this process. The concentration of radiation and the heat flow were simulated in each 0.1m² of the dome using the metrological parameters of Morocco’s region Rabat-Salé-Kenitra. The results can follow the evolution of the temperature of glass, salt water, point dew temperature, saturation pressure and evaporation rate as well as humidity reached in August month for the study zone. For this, a numerical implementation on Matlab and Ansys are compared with measurements for the same parameters shown in the domain study of single slope. The comparison results are more significant by the rise of the ray concentration rate reached to 99% if the inclination angle of the heliostat is divided into three intervals. The saturation pressure increases as long as with the rate of evaporation and the humidity that produces ordinary daily fresh water.

This work aims to make a unique polymer to be used as a conductive and flexible chip antenna. Its properties are robustness, rigidity, stretchability, and good conduction. The fabricated composite is composed of two copolymers, Polydimethylsiloxane (PDMS) and Polyethylenimine (PEI), assembled with nano metals (Copper, Silver), and graphene nanoparticles as a matrix. Nano metals fill out the inter-layer space, and polymer voids reinforce the cross linker. Graphene/metal nanoparticles help make chelating complexes using metallic bonds, enhancing the polymer’s conductivity from 1.87 × 10-4 to 5.64 ×10-6 σ Scm-1. The conductivity, self-healing, and surface morphology of fabricated composite are analyzed using different spectroscopic techniques, such as electrochemical impedance (EIS), Scanning Electronic Microscopy (SEM), Transition Electronic Microscopy (TEM), Infrared spectroscopy (IR), UV-Visible spectroscopy (UV), and a particle size analyzer.