Abstract: Solution for a normally loaded infinite isotropic plate containing five cracks with coalesced yield zones is obtained using a complex variable method. Influence of coalesced yield zones on the load bearing capability of the infinite plate is analyzed. Analytical expressions for stress intensity factors, displacement components and crack opening displacement (COD) are obtained. Numerical study is carried out to determine the yield zone length, applied load ratio and COD. The numerical results are reported graphically between some important parameters.

DOI: 10.5267/j.esm.2022.6.006
Keywords: Dugdale model, Crack-tip opening displacement (CTOD), Collinear cracks, Complex variable method, Stress intensity factor, Multi-site damage problem, Unified yield zones

	© 2010 by the authors; licensee Growing Science, Canada. This is an open access article distributed under the terms and conditions of the license. Creative Commons Attribution (CC-BY)

Abstract: 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.

DOI: 10.5267/j.esm.2022.6.005
Keywords: Functionally graded material, Stress intensity factor, Stress concentration factor, Edge crack, Circular hole, XFEM

	© 2010 by the authors; licensee Growing Science, Canada. This is an open access article distributed under the terms and conditions of the license. Creative Commons Attribution (CC-BY)

Abstract: 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.

DOI: 10.5267/j.esm.2022.6.004
Keywords: Hardness, Optimization, RSM, Tensile strength, Welding

	© 2010 by the authors; licensee Growing Science, Canada. This is an open access article distributed under the terms and conditions of the license. Creative Commons Attribution (CC-BY)

Abstract: 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.

DOI: 10.5267/j.esm.2022.6.003
Keywords: Elastomers, Hyperelasticity, Stored energy function, Incompressibility, Polyconvexity

	© 2010 by the authors; licensee Growing Science, Canada. This is an open access article distributed under the terms and conditions of the license. Creative Commons Attribution (CC-BY)

Abstract: 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.

DOI: 10.5267/j.esm.2022.6.002
Keywords: Cryomilling, Vibratory mill, The mode of the cryogenic-vibration grinding process, Fluoroplast, Radiation-protective composite materials

	© 2010 by the authors; licensee Growing Science, Canada. This is an open access article distributed under the terms and conditions of the license. Creative Commons Attribution (CC-BY)

Abstract: 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.

DOI: 10.5267/j.esm.2022.6.001
Keywords: Cyclic lateral loads, Ductility, Exterior Beam-Column Joints Finite Element Method, Self Compacting Concrete

	© 2010 by the authors; licensee Growing Science, Canada. This is an open access article distributed under the terms and conditions of the license. Creative Commons Attribution (CC-BY)

Abstract: 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.

DOI: 10.5267/j.esm.2022.5.001
Keywords: Photovoltaic energy, Solar energy, Off-grid system, On-grid system, Hybrid system

	© 2010 by the authors; licensee Growing Science, Canada. This is an open access article distributed under the terms and conditions of the license. Creative Commons Attribution (CC-BY)

Abstract: 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).

DOI: 10.5267/j.esm.2022.6.099
Keywords: Stress intensity factor, Semi-elliptical surface crack, Corner point singularity, Torsion, FEM, DBEM

	© 2010 by the authors; licensee Growing Science, Canada. This is an open access article distributed under the terms and conditions of the license. Creative Commons Attribution (CC-BY)