Browsing by Author "Kumar, Raman"

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Citation Count: 0
Examination of the mechanical properties of porous carbon matrix by considering the Nanovoids: A computational study using molecular dynamics simulation
(Pergamon-elsevier Science Ltd, 2025) Sun, Shuai; Ali, Ali B. M.; Babadoust, Shahram; Al-Zahiwat, Murtadha M.; Kumar, Raman; Chaudhary, Rahul Raj; Emami, Nafiseh
This study explored the effect of nanovoid size on the mechanical properties of polymer-carbon matrices through detailed molecular dynamics simulations. The investigation focused on spherical nanovoids with radii of 5, 7, 10, 12, and 15 & Aring;, evaluating their effects on critical mechanical properties, such as Young's modulus and ultimate strength. The Tersoff potential was employed to accurately model the atomic and mechanical behavior of the polymer-carbon matrix, considering the presence of these nanovoids. The simulation results indicate that the potential energy and total energy stabilized at-132,279.23 eV and- 131,522.4 eV, respectively, confirming the physical stability of simulated samples. On the other hand, the findings reveal that for a nanovoid radius of 5 & Aring;, the ultimate strength and Young's modulus were 36.41 GPa and 424.93 GPa, respectively. As the radius of nanovoids increased from 5 & Aring; to 15 & Aring;, both ultimate strength and Young's modulus exhibited a decreasing trend, with values dropping from 36.41 GPa and 424.93 GPa to 31.18 GPa and 364.39 GPa, respectively. Moreover, larger nanovoids contributed to increased flexibility and a higher critical strain in the polymer-carbon matrix. This systematic analysis of nanovoid size effects provided a new perspective on void engineering within composites. By enhancing the theoretical understanding of how void dimensions affected material properties, the study offered significant insights for optimizing the mechanical performance of advanced materials and advancing the field of structural engineering.
Citation Count: 0
Investigating the effect of welding tool length on mechanical strength of welded metallic matrix by molecular dynamics simulation
(Elsevier Science inc, 2024) Yang, Xuejin; Salahshour, Soheıl; Saleh, Sami Abdulhak; Al-Bahrani, Mohammed; Manjunath, C.; Kumar, Raman; Sabetvand, Rozbeh
The welding process and the properties of welding instruments may improve the mechanical performance of an item. One of these properties is the length of the welding tool. This approach has a substantial effect on the mechanical strength of the metallic matrix. The current study used molecular dynamics modeling and LAMMPS software to evaluate the effect of welding tool length on the mechanical properties of a welded Cu-Ag metallic matrix. This simulation makes use of the Lennard-Jones potential function and the embedded atom model. First, the equilibrium phase of modeled samples was verified by changing the computation of kinetic and total energies. Next, the mechanical properties of the welded matrix were studied using the stated Young's modulus and ultimate strength. The stress-strain curve of samples demonstrated that the mechanical strength of atomic samples increased as the length of the welding tool (penetration depth) increased. Numerically, by increasing the tool penetration depth of Fe tools from 2 & Aring; to 8 & Aring;, Young's modulus and ultimate strength of the matrixes sample increase from 34.360 GPa to 1390.84 MPa to 38.44 GPa and 1510 MPa, respectively. This suggested that the length of the Fe welding tool significantly affected the mechanical properties of the welded metallic matrix. The longer the length of Fe welding tools, the more particles were involved, and consequently, more bonds were formed among the particles. Bonding among the particles caused changes in mechanical properties, such as greater ultimate strength. This method can optimize mechanical structures and be useful in various industries.
Citation Count: 0
Investigation of mechanical behavior of porous carbon-based matrix by molecular dynamics simulation: Effects of Si doping
(Elsevier Science inc, 2024) Ma, Weifeng; Salahshour, Soheıl; Salahshour, Soheil; Abdullah, Zainab Younus; Al-Bahrani, Mohammed; Kumar, Raman; Esmaeili, Sh.
Understanding the mechanical properties of porous carbon-based materials can lead to advancements in various applications, including energy storage, filtration, and lightweight structural components. Also, investigating how silicon doping affects these materials can help optimize their mechanical properties, potentially improving strength, durability, and other performance metrics. This research investigated the effects of atomic doping (Si particle up to 10 %) on the mechanical properties of the porous carbon matrix using molecular dynamics methods. Young's modulus, ultimate strength, radial distribution function, interaction energy, mean square displacement and potential energy of designed samples were reported. MD outputs predict the Si doping process improved the mechanical performance of porous structures. Numerically, Young's modulus of the C-based porous matrix increased from 234.33 GPa to 363.82 GPa by 5 % Si inserted into a pristine porous sample. Also, the ultimate strength increases from 48.54 to 115.93 GPa with increasing Si doping from 1 % to 5 %. Silicon doping enhances the bonding strength and reduces defects in the carbon matrix, leading to improved stiffness and load-bearing capacity. This results in significant increases in mechanical performance. However, excess Si may disrupt the optimal bonding network, leading to weaker connections within the matrix. Also, considering the negative value of potential energy in different doping percentages, it can be concluded that the amount of doping added up to 10 % does not disturb the initial structure and stability of the system, and the structure still has structural stability. So, we expected our introduced atomic samples to be used in actual applications.