Abstract
The optimum machining parameters of milling operations are of great concern with manufacturing environment. The aim of the work is to observe the impact of variables on outcomes like surface roughness and material removal rate for EN8 and EN31steels. In these, EN8 are used for moderately stressed parts of motor vehicles while EN31 are used for components that are subjected to severe abrasion, wear or high surface loading due to its high resisting nature against wear. The experiments have conducted on a vertical milling machine using a carbide tool. This investigation deals with the optimization of the milling parameters, as spindle speed, feed rate and depth of cut by using Taguchi's optimization and GRA techniques to select the best combination of input parameters towards maximum material removal rate and minimum surface roughness for these materials. These milling parameters were optimized by utilizing Taguchi's L9 orthogonal array, signal-to-noise ratios and analysis of variance. The analysis reveals that the spindle speed is the dominant factor affecting surface roughness and MRR. Spindle speed contributes 97.38% and 72.39% for SR and 51.37% and 14.45% for MRR towards EN8 and EN31 respectively. The response table of S/N ratios for GRG ranked spindle speed at1 for EN8 and EN31 individually. Further, the optimum level of process parameters for attaining optimal values of outcomes by employing GRA. The gray relational analysis reveals that the spindle speed at 228 rpm is the dominant factor affecting the consequences.
Key Words
EN8 and EN31 steel alloy; GRA; MRR; surface roughness; Taguchi method
Address
Mohd Saif, Shahadat Hasan and Ritik Kumar Rawat:Department of Mechanical Engineering, Sam Higginbottom University of Agriculture, Technology and Sciences (SHUATS), Prayagraj, India
Mohsin Jamal: Department of Civil Engineering, Aliah University, Kolkata, India
Ahmed Amine Daikh, Amine Chergui, Abdessamed Amara, Azzedine Brik,
Mohamed Ouejdi Belarbi, Mohamed Sid Ahmed Houari,
Azza M. Abdraboh and Mohamed A. Eltaher
Abstract
This study presents a corrigendum regarding the inclusion of porosity in functionally graded structures. Typically, researchers incorporate the porosity function into the rule of mixture without accounting for specific fabrication steps, which relate to the proportions of the material constituents as represented by the volume fraction. This paper investigates the free vibration of functionally graded plates analytically and proposes a novel approach to porosity inclusion, where the porosity function is directly related to the volume fraction. Tow schemes of porosity are analysed, volume fraction porosity-dependent (VFD) and rule of mixture porosity dependent (RMD). Four types of porosity are proposed, Even, Uneven, linear (1) and linear (2). Based on the generalized field of displacement, a new higher-order shear deformation theory is proposed in this work. The equilibrium equations are performed on the basis of the virtual work principle, and solved by applying Galerkin method to cover various boundary conditions. The influence of the structure geometry, materials combination parameter, type of porosity, and different boundary conditions on the vibration frequency of the FG plate is investigated in detail.
Address
Ahmed Amine Daikh: Artificial Intelligence Laboratory for Mechanical and Civil Structures, and Soil, University Centre of Naama, P.O. Box 66, Naama 45000, Algeria/ Laboratoire d'Etude des Structures et de Mécanique des Matériaux, Département de Génie Civil, Faculté des Sciences et de la Technologie, Université Mustapha Stambouli B.P. 305, R.P.29000 Mascara, Algérie
Amine Chergui, Abdessamed Amara and Azzedine Brik: Department of Mechanical Engineering, University Centre of Naama, 45000, Algeria
Mohamed Ouejdi Belarbi: Laboratoire de Recherche en Génie Civil, LRGC, Université de Biskra, B.P. 145, R.P. 07000, Biskra, Algeria
Mohamed Sid Ahmed Houari: Laboratoire d'Etude des Structures et de Mécanique des Matériaux, Département de Génie Civil, Faculté des Sciences et de la Technologie, Université Mustapha Stambouli B.P. 305, R.P.29000 Mascara, Algérie
Azza M. Abdraboh: Physics Department, Faculty of science, Benha university, Benha, Egypt
Mohamed A. Eltaher:6 Faculty of Engineering, Mechanical Engineering Department, King Abdulaziz University, P.O. Box 80204, Jeddah, Saudi Arabia/ Faculty of Engineering, Mechanical Design and Production Department, Zagazig University, P.O. Box 44519, Zagazig, Egypt
Abstract
The paper presents a novel plastic-damage constitutive model for two types of lightweight concrete (LWC), namely aerated concrete (AC) and recycled coarse concrete with no fine aggregate (RC). The model has the potential to improve the ductility and toughness of the LWC, while simultaneously reducing its damage level. The amount of silica fume (SF) used in the concrete mix determines the extent of these improvements. Therefore, an experimental investigation was used to determine the optimal percentage of (SF) that should be used in the proposed model for the two types (LWC). These types of concrete included recycled coarse aggregate at a ratio of 6:1 to the amount of cement, which allowed for the incorporation of waste materials into the concrete mix. Additionally, aerated concrete (AC) was produced by adding composite fly ash (FA) and aluminum powder (AL) in proportions of 10% and 0.2%, respectively, based on the weight of the cement fresh and hardened concrete tests were carried out, for 7,14, and 28 days on the samples tested consisted of 36 cubes measuring 150 x 150 x 150 mm and 9 cylinders measuring 150 mm in diameter and 300 mm in height, the highest compressive strength was achieved when using an optimal proportion of SF and FA in AC3 and RC3 for aerated and recycled (LWC), respectively. This proportion involved a 20% addition of silica fume (based on cement content). Furthermore, the numerical study demonstrated that the proposed algorithm is effective and resilient in finite element analysis FEA ABAQUS software to develop a concrete plastic-damage (CDP) constitutive model suitable for RC3 and AC3 to simulate the tension stiffening behavior with stress strain diagram. This model employs two damage variables to represent tensile and compressive damage independently. Furthermore, this model utilizes a combined approach of continuum damage mechanics and plasticity theory, which is known as the compression cylinder model of lightweight concrete with a damage plasticity (CDP) method. These investigations also provide valuable insights into the impact of SF on the plasticity behavior of LWC concrete, which can enhance its ductility, and toughness, and reduce its damage level depending on the percentage of SF. In addition, the numerical results employ statistical regression analysis to establish the equations that indicate the relationship between compression stress and tensile strength (ƒc and ƒt) for high-strength values from all samples (AC3 and RC3).
Key Words
ABAQUS /CAE; aerated concrete; lightweight concrete; no fine concrete; silica fume; plastic concrete damage; stress-strain relations
Address
Lamiaa K. Idriss: Department of Civil Engineering, Sphinx university, Assiut, Egypt
Yasser A.S Gamal: Department of Civil Engineering, High Institute of Engineering Technology, EL-MINA, Egypt/ Department of Civil Engineering, Faculty of Engineering, NUB university, Egypt
Victor Stanevich, Galiya Rakhimova, Olga Vyshar, Leonid Bulyga, Murat Rakhimov, Bayan Kudryshova, Gulnaz Ibraimbaeva, Murat Beisembaev and Alibek Zhakanov
Abstract
The relevance of this study is conditioned by the need to solve environmental, economic, and engineering problems of disposing of coal mining overburden rocks from the Ekibastuz coal basin. This article analyzes the properties of coal mining overburden rocks and the possibility of producing ceramic building materials on their basis. The features of the stones depending on their lithological type and occurrence horizons are identified during a set of electronic microscopic, X-ray phase, petrographical, and chemical tests conducted by modern test methods. This work studies the physico-mechanical properties and the chemical and mineralogical composition of coal mining overburden rocks. It reveals their similarity to conventional argillous raw materials used for producing ceramic building materials. The content of the article is of practical value for both, coal industry enterprises producing overburden rocks as production wastes and for enterprises producing ceramic building materials. These materials can significantly reduce the prime cost of manufactured products and fill the lack of on-spec argillous raw materials when using coal mining overburden rocks.
Key Words
ceramic materials; chemical composition; overburden rocks; strength
Address
Victor Stanevich, Olga Vyshar, Leonid Bulyga, Bayan Kudryshova and Murat Beisembaev: 1Faculty of Architecture and Construction, Toraighyrov University, Lomov st. 64, Pavlodar, 140000 Republic of Kazakhstan
Galiya Rakhimova and Murat Rakhimov: Department of Building Materials and Technologies, Karaganda Technical University, Nazarbayev av. 56, Karaganda, 100032 Republic of Kazakhstan
Alibek Zhakanov: Department of Technology of Industrial and Civil Engineering, L.N. Gumilyov Eurasian National University, Kazhymukan st.13, Astana,1310000 Republic of Kazakhstan
Gulnaz Ibraimbaeva: International Educational Corporation, Ryskulbekova st. 28, Almaty, Republic of Kazakhstan
Abstract
Most studies on stress-strain relationships in compression have relied on limited experimental data, resulting in models that often lack general applicability. This study aimed to evaluate the relevance and accuracy of existing stress-strain models across a range of concrete grades. Graphical, analytical and statistical methods were used to compare the predicted and measured stress-strain responses. Whereby ten stress-strain curves for normal to high strength concrete, with peak compressive stresses ranging between 18 MPa to 121 MPa, were selected and applied to selected established stress-strain models from the literature. The graphical comparison assessed ability of each model to replicate both the ascending and descending branches of the stress-strain curve in a normalized format. To further assess predictive performance analytically, each selected model was evaluated based on normalized toughness and ductility index. Additionally, root mean square error and coefficient of variation were calculated to statistically validate the accuracy of the predictions. The conclusion of this study indicate that most models were found to inadequately capture both the ascending and descending branches of the stress-strain curve across all concrete grades. While the best-performing model achieved higher accuracy, involved multiple equations, making it complex to implement. These findings highlight the need for a novel model that incorporates easily measurable parameters, such as compressive strength and uses a single equation to predict both branches of the curve, ensuring broad applicability across concrete grades.
Key Words
high strength concrete; load-deformation behaviour; normal strength concrete; stress-strain relationship
Address
Gopal Paliwal and Shiwanand R. Suryawanshi: Department of Civil Engineering, Sardar Vallabhbhai National Institute of Technology, Surat, Gujarat, India 395007
