فهرس المقالات Mechanical Property

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  1 - Thermomechanical Properties of the Polymeric Nanocomposite Predicted by Molecular Dynamics
  Majid Hadipeykani farshid Aghadavoudi Davood Toghraie
  A molecular dynamics simulation study is employed to investigate the elastic and basic thermal properties of thermoset polymer based nanocomposite sample reinforced by CNT. The COMPASS force filed was used to construct the simulation box. The simulation box contains the أکثر

  A molecular dynamics simulation study is employed to investigate the elastic and basic thermal properties of thermoset polymer based nanocomposite sample reinforced by CNT. The COMPASS force filed was used to construct the simulation box. The simulation box contains the cured epoxy resin molecules obtained from cross linking process of DGEBA and DETA which were located around the CNT (10,10). NVT and NPT ensembles were performed to equilibrate the system and convergence of temperature, energy and density have been checked. The elastic constants of molecular sample of nanocomposite were determined based on stiffness matrix and compared with the molecular results of pure resin. The results show that the Young's modulus in the transverse direction of nanocomposite model is less than that in longitudinal direction indicating the transversely isotropic behaviour at atomic scale. Glass transition temperature (Tg) and coefficient of thermal expansion (CTE) were calculated through the linear fitting of density-temperature diagram for the CNT-reinforced nanocomposite model. Atomistic simulation results showed decrease in Tg and CTE comparing to the pure epoxy. Moreover, the simulation results were compared with the measured values and good agreements are observed. تفاصيل المقالة
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  2 - Macro-and micromechanical modelling of HA-Elastin scaffold fabricated using freeze drying technique
  Matin Mohammadzadeh Rad Saeed Saber-Samandari Mojtaba Sadighi Lobat Tayebi Mohammad Mohammadi Aghdam Amirsalar Khandan
  10.22034/jna.2020.1900107.1213
  Abstract. Since osteomyelitis is a serious and dangerous disease, it requires immediate treatment with antibiotics or bone substitute replacement in orthopedic surgeries. Therefore, a porous polymeric-ceramic was fabricated using hydroxyapatite (HA) and polymethylmethac أکثر

  Abstract. Since osteomyelitis is a serious and dangerous disease, it requires immediate treatment with antibiotics or bone substitute replacement in orthopedic surgeries. Therefore, a porous polymeric-ceramic was fabricated using hydroxyapatite (HA) and polymethylmethacrylate (PMMA) composed with elastin as an ideal scaffold for bone tissue engineering applications. The current study is aimed at investigating the effects of various amounts of elastin biopolymer on porous bio-nanocomposite scaffold using the freeze-drying (FD) technique. The morphology and phase analysis of the prepared scaffold are analyzed using scanning electron microscope (SEM) and X-ray diffraction (XRD) techniques. The biological performance of the porous tissue is evaluated in simulated body fluid (SBF) and sodium chloride (SC) solution. The tensile test is used to measure the elastic modulus and tensile strength of the porous tissue before soaking in the SBF. The obtained result is simulated using micromechanical model from the experimental values. The elastic modulus of samples decreases from 1.18 MPa to 0.69 MPa, and porosity evaluation is in the range of 70-85% with addition of 10 wt% and 15 wt% elastin to PMMA-HA bio-nanocomposite. The biological behavior indicates that a thick apatite layer precipitate on the surface of the sample with 10 wt% elastin beside increases alkaline group with constant pH concentration. According to the obtained porosity and elastic modulus results, suitable micromechanical model is assessed. The comparison of micromechanical model is assessed, and error rate was less than 10%; therefore, optimum model is introduced as the best micromechanical model for porous bone substitute. تفاصيل المقالة
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  3 - Macro-and micromechanical modelling of HA-Elastin scaffold fabricated using freeze drying technique
  Matin Mohammadzadeh Rad Saeed Saber-Samandari Mojtaba Sadighi Lobat Tayebi Mohammad Mohammadi Aghdam Amirsalar Khandan
  10.22034/jna.2021.681545
  Since osteomyelitis is a serious and dangerous disease, it requires immediatetreatment with antibiotics or bone substitute replacement in orthopedic surgeries.Therefore, a porous polymeric-ceramic was fabricated using hydroxyapatite(HA) and polymethylmethacrylate (PMMA) أکثر

  Since osteomyelitis is a serious and dangerous disease, it requires immediatetreatment with antibiotics or bone substitute replacement in orthopedic surgeries.Therefore, a porous polymeric-ceramic was fabricated using hydroxyapatite(HA) and polymethylmethacrylate (PMMA) composed with elastin as an idealscaffold for bone tissue engineering applications. The current study is aimed atinvestigating the effects of various amounts of elastin biopolymer on porous bionanocompositescaffold using the freeze-drying (FD) technique. The morphologyand phase analysis of the prepared scaffold are analyzed using scanning electronmicroscope (SEM) and X-ray diffraction (XRD) techniques. The biologicalperformance of the porous tissue is evaluated in simulated body fluid (SBF) andsodium chloride (SC) solution. The tensile test is used to measure the elasticmodulus and tensile strength of the porous tissue before soaking in the SBF. Theobtained result is simulated using micromechanical model from the experimentalvalues. The elastic modulus of samples decreases from 1.18 MPa to 0.69 MPa,and porosity evaluation is in the range of 70-85% with addition of 10 wt% and 15wt% elastin to PMMA-HA bio-nanocomposite. The biological behavior indicatesthat a thick apatite layer precipitate on the surface of the sample with 10 wt%elastin beside increases alkaline group with constant pH concentration. Accordingto the obtained porosity and elastic modulus results, suitable micromechanicalmodel is assessed. The comparison of micromechanical model is assessed, anderror rate was less than 10%; therefore, optimum model is introduced as the bestmicromechanical model for porous bone substitute. تفاصيل المقالة
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  4 - Investigation of ECAR Routes on Mechanical Properties of Explosive-Welded Al-Cu Bimetal
  Mohammad Honarpisheh Mahdi Dehghani Sina Ghaffari
  Equal channel angular rolling (ECAR) is a severe plastic deformation method that covered plastic deformation of sheets. In this study, effects of ECAR route shave been investigated on the mechanical and microstructure properties of explosive-welded Al-Cu bimetal. At fir أکثر

  Equal channel angular rolling (ECAR) is a severe plastic deformation method that covered plastic deformation of sheets. In this study, effects of ECAR route shave been investigated on the mechanical and microstructure properties of explosive-welded Al-Cu bimetal. At first, the explosive welding process has been performed to prepare the Al-Cu bimetals. Then, to relieve the stress and preparing of samples for ECAR process, the annealing process of the samples was done. Finally, the ECAR process was performed on the samples in two routes A and C. Results showed that yield and tensile strengths and micro hardness of ECARed samples significantly increased with increasing the number of passes, whereas their ductility decreased. The yield strength of bimetals has been increased from 80 MPa to 100 MPa and 130 MPa at the routes A and C, respectively. Also, with increasing the number of ECAR passes, the grain size of the ECARed bimetals decreased to about 2μm. تفاصيل المقالة