Abstract
A present model was deployed to forecast the impact of transverse cracking on stiffness degradation in [0/90]2s composite laminates subjected to simple bending. Good alignment between the predictive model and empirical data from Smith and Ogin (2000) was achieved. The composite's material properties, influenced by temperature and moisture variations, are derived from a micromechanical laminate model. The transient and non-uniform moisture concentration distribution give rise to the transient elastic moduli of cracked composite laminates. This asymmetrical environment is considered in to evaluate changes in normalized axial and flexural modulus due to transverse cracking. The results adeptly depict the relationship between stiffness degradation and crack density, alongside operational temperature. Notably, composite laminates with transverse cracks undergoing simple bending exhibit less susceptibility to asymmetrical environment compared to those under tension loading. This theoretical study aims to enhance understanding of aged composite materials afflicted by matrix cracking.
Address
Mohamed Khodjet Kesba, B. Boukert and A. Benkhedda: Aeronautical Sciences Laboratory, Institute of Aeronautics and Space Studies, University of Blida 1, BP 270 Route de Soumaa, Blida 09000, Algeria
E.A. Adda bedia: Laboratory of Materials and Hydrology, University of Sidi Bel Abbes, Sidi Bel Abbes, Algeria
Abstract
This study investigates the coupled effects of loading types, thickness stretching, Winkler–Pasternak and Kerr foundation variations on the flexural behaviour of simply supported functionally graded (FG) plates. A simplified quasi-3D high-order shear deformation theory incorporating integral terms is used. The governing equilibrium equations consider the interaction between the loading type and the variation of Winkler–Pasternak and Kerr foundation parameters. The numerical results for non-dimensional stresses and displacements are obtained using the virtual displacement principle and Navier's solution technique. The accuracy of the non-dimensional formulas is validated against existing literature, demonstrating excellent agreement. Additionally, several parametric studies examine the effects of various geometric and material factors. This analytical model is well suited for analyzing the bending behaviour of simply supported FG plates in specific engineering applications.
Key Words
elastic bending; FG Plate; Navier solution; partial foundation; partial loads; Quasi-3D theory; virtual work principle
Address
Mounir Takouachet: Civil Engineering Department, Faculty of Technology, University of Sidi Bel Abbes, BP 89, Sidi Bel Abbes 22000, Algeria
Abderrahmane Menasria and Abdelhakim Bouhadra: Civil Engineering Department, Faculty of Sciences and Technology, University of Khenchela, BP 1252 Road of Batna, Khenchela 40000, Algeria/ Materials and Hydrology Laboratory, University of Sidi Bel Abbes, BP 89, Sidi Bel Abbes 22000, Algeria
Nabil Himeur: Mechanical Engineering Department, Faculty of Sciences and Technology, University of Khenchela, BP 1252 Road of Batna, Khenchela 40000, Algeria
Abdelouahed Tounsi: Materials and Hydrology Laboratory, University of Sidi Bel Abbes, BP 89, Sidi Bel Abbes 22000, Algeria/ Department of Civil and Environmental Engineering, King Fahd University of Petroleum & Minerals, 31261 Dhahran, Eastern Province, Saudi Arabia
Abstract
Carrageenan, an anionic polysaccharide commercially extracted from red algae, possesses ester sulphate functional groups, endowing it with significant potential as an adsorbent for heavy metal cations. This study investigates the efficacy of κ-carrageenan beads for the removal of manganese(II) ions from contaminated aqueous solutions, addressing the environmental concerns associated with elevated Mn(II) concentrations. κ-carrageenan beads were successfully synthesized from commercially available powder, and their adsorption capabilities were confirmed through Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscopy (SEM). Adsorption parameters were systematically optimized, revealing optimal conditions at pH 3, a contact time of 120 minutes, and an adsorbent dosage of 0.1 g/100 mL. Kinetic study demonstrated that the adsorption process followed pseudo-second-order kinetics, while equilibrium data conformed to the Langmuir adsorption isotherm model, indicating monolayer adsorption. Furthermore, thermodynamic studies revealed that the adsorption of Mn(II) onto κ-carrageenan beads was an endothermic and spontaneous process. These findings can serve as a valuable reference for further applications of this material as a relatively low-cost, easy-to-prepare, yet effective bio-based adsorbent in reducing Mn(II) pollution levels in open waters.
Key Words
adsorption; hydrogel beads; κ-carrageenan; manganese ion
Address
Syifabudi Chairurrizky, Muhammad Iqbal, Rusnadi and Muhammad Bachri Amran: Analytical Chemistry Research Group, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha No. 10, Bandung, 40135, Jawa Barat, Indonesia
Abstract
In this paper, thermo-mechanical elastic stress and deformation analysis of a functionally graded (FG) cylindrical shell, under complex loading states such as angular rotation, thermal load with heat generation, body force, and mechanical loads, are analyzed. FG materials are advanced and futuristic composite materials with gradually varying properties across different surfaces. In this paper, a power law is used for the variation of material properties such as elastic modulus, density, thermal conduction coefficient, and thermal expansion coefficient, offering a better strength-to-weight ratio, better thermal resistance, and durability in critical harsh environments. To increase the lifecycle of a structure, the stresses induced should be minimal. Navier's method is used to solve Euler's governing differential equations with a plane stress condition that reduces the complexity of the second-order. The main aim of this study is to investigate the combined effect of material non-homogeneity with various types of complex loading states on the displacement and stress distribution within the cylinder. This analysis provides valuable insight to enhance the performance, reliability, and integrity of structures in the fields of aerospace, defense, Mechanical, and Civil Engineering.
Key Words
FGM; hollow cylinder; material grading laws; Navier's method; thermo-mechanical analysis
Address
Sanjay Kumar Singh: Department of Mechanical Engineering, Chhatrapati Shivaji Institute of Technology Durg
Lakshman Sondhi: Department of Mechanical Engineering, Shri Shankaracharya Technical Campus Bhilai
Abstract
The kinetics of plastic flow localization in low carbon steel/stainless chromium-nickel steel (ASTM A414 grade A / AISI 304) composite under uniaxial tensile testing is studied via digital speckle image correlation method. The types and parameters of local deformation in the base and cladding layers of the composite are determined at different stages of work hardening. It is found that in the low carbon steel basal layer, the distribution of localized deformation at the yield plateau represents a single localized front similar to the Lüders band. In the austenitic steel coating layer, the distribution of localized deformation at the yield plateau represents localized fronts similar to the Portevin–Le Chatelier effect bands.
Key Words
composite; deformation fields; digital image correlation; Lüders band; steel; tensile testing
Address
Svetlana A. Barannikova and Yulia V. Li: Strength Physics Laboratory, Institute of Strength Physics and Materials Science, Siberian Branch of Russian Academy of Science, Tomsk 634055, Russia
