جستجوی مقالات مرتبط با کلیدواژه « مدول یانگ » در نشریات گروه « برق »

In this study, the mechanical behavior of the newest allotrope of carbon called biphenylene network (BPN) has been investigated using molecular dynamics simulations. The structure of BPN consists of four, six, and eight-membered carbon rings hybridized with sp2. In this study, the interatomic potential is considered to be AIRBO, and the tensile behavior of this structure has been modeled at different temperatures. After simulation, the Young's modulus and yield stress of biphenylene at different temperatures have been obtained in the armchair direction and zig-zag direction. The Young's modulus in the zig-zag direction at all temperatures is about 14 to 29% higher than the other direction, which indicates the orthotropic behavior of this structure. In addition, with the increase in temperature, the failure strain and Young's modulus have decreased due to the increase in the distance between the atoms and the decrease in energy. It has also been shown that the failure of BPN is brittle. The results of this study show that BPN shares some of the exceptional properties of graphene.

Considering the increasing use of nanotubes in various industries, it is of great importance to investigate the mechanical properties of these nanostructures. Today, due to the extraordinary properties that nanotubes have shown in various sciences, they have attracted the attention of many scientists. Boron nitride nanotubes are a form of boron nitride that are structurally very similar to carbon nanotubes. Many studies have been done to achieve the mechanical properties of these materials, and scientists have achieved this with different methods. But finding an easy and simple solution has always been the focus of many scientists who are still trying to achieve it. In this study, the molecular mechanics and solid mechanics properties of boron nitride nanotubes have been studied using a mechanical model to predict Young's modulus; and a spatial structure consisting of a unit cell has been used to describe the mechanical response of boron nitride nanotubes to applied loading. According to this assumption, a new unit cell, named mechanical unit cell, is introduced here to make a boron nitride plate or wall of boron nitride nanotubes. The analytical research presented in this research provides a simple method for predicting the Young's modulus of boron nitride nanotubes, and the obtained results are in good agreement with experimental and theoretical data.

Young's modulus of blends of thermoplastic polyurethane (TPU) and acrylonitrile butadiene styrene (ABS) are measured with different weight percentage (blend ratio). The results of the different micromechanical models prediction of Young's modulus, based on both droplet matrix and co-continuous morphology, are compared with experimental results. Both two-dimentisional models like series, parallel, Maxwell, Halpin-Tsai, Takayanagi, Davis, Coran and Patel, and three-dimensional models like Kolarik, Barentson and Nijhof are used for Young's modulus prediction of polymer blends. In this work, an emphasis was given to the effect of weight percentage on morphology and mechanical properties of the blend. Scanning electronic microscopy shows droplet matrix morphology in the presence of less than 20 wg% ABS in TPU matrix but in 70/30 TPU/ABS blend ratio, ABS phase dispersed like elongated elliptical and phase inversion happened. In the 95/5, 90/10 and 80/20 blend ratio which ABS droplets dispersed uniformly throughout the TPU matrix, Parallel Takayanagi and Barentson series model of parallel parts, could predict Young's modulus with good accuracy. In the 70/30 blend ratio which phase inversion was observed and both phases are somehow continuous, Coran-Patel, series Nijhof and Kolarik models were accurate.