جستجوی مقالات مرتبط با کلیدواژه « نانو رس » در نشریات گروه « مکانیک »

In this paper, experimental investigation and regression analysis are investigated on plastic deformation of polyurethane composite sandwich panels reinforced with nanoclay under blast loading. For this purpose, polyurethane sandwich panels were prepared with different percentages of nanoclay and in different densities. The mechanical properties of nanoclayreinforced foams were studied by the tensile-compression test. Explosive shock tube device and C4 explosive material were used for explosive loading. Then, the response surface methodology was used to investigate the effect of significant parameters, the percentage of nanoclay and density of polyurethane foam, on the displacement of composite sandwich panels and to optimize the parameters for minimum deformation. The results obtained from the regression model at 95% confidence level indicate a very good agreement between the experimental results and the values predicted by the model. The high value of the correlation coefficient between the studied parameters and the amount of plastic deformation of the sandwich panel (R2 = 99%) indicate that the proposed model has higher accuracy. Finally, the optimal conditions for achieving the minimum displacement of composite sandwich panels were determined as 1.57% nanoclay content and foam density of 130 kg/m3.

In this study, using design of experiments, the effect of the total weight percentage of graphene nanosheets and nano clay and their weight ratio and weight percentage of compatibilizer (PPg-MA) on the tensile properties of polypropylene/ graphene/ nano clay/ PP-g-MA nanocomposites were investigated. Design of experiments and analysis of experimental data with Minitab 16 software and response surface methodology were carried out. Making nanocomposites, based on the melt mixing was performed. All combinations and pure states materials were mixed together in a co-rotating twin-screw extruder and then injection molded into standard tensile test samples. The tensile properties of all samples including tensile strength, Young's modulus and elongation at break was studied experimentally. Statistical models provided by response surface methodology had good agreement with experimental findings. Statistical analysis showed that with increasing the percentage of nanoparticles, tensile strength and elongation at break of nanocomposites reduced. Also increasing the percentage of nanoparticles increase the stiffness of nanocomposites without compatibilizer, however, with the increasing amount of compatibilizer, reduced modulus. Compounds morphology by Scanning Electron Microscopy (SEM) was performed. Micrographes showed better dispersion of the particles in lower percentages.

In this paper, the tensile properties of 2D woven glass epoxy composite reinforced by two different nanoparticles have been investigated and compared. Hand lay-up method has been used to manufacture nanocomposites with 12 layers of 2D woven glass fibers with 40% fiber volume fraction. The nano-epoxy resin system is made of epon 828 resin with jeffamine D400 as the curing agent. The composites were reinforced by adding organically modified montmorillonite nanoclay (Closite 30B) and nanosilica (SiO2) particles. The nanoclay particles were dispersed into the epoxy system in a 0%, 3%, 5%, 7% and 10% ratio in weight with respect to the matrix, while the spherical nanosilica particles were dispersed into the epoxy system in a 0%, 0.5%, 1% and 3% ratio in weight with respect to the matrix. The results show that low loading of nanoclay decreases the mechanical properties of nanocomposite, while significant improvements of nanocomposite mechanical properties are shown in low loading of nanosilica. Tensile strength and toughness of nanocomposite increase by 7% and 10% after adding 5 wt.% nanoclay. Loading of 0.5 wt.% nanosilica cause 10% and 27% improvement in tensile strength and toughness of nanocomposite.

This paper investigated experimentally the effect of nanoclay on ballistic impact behavior of GLARE. The prepared GlARE is made of two Aluminum 2024 facing sheets and E glass/ epoxy/nanoclay as nano composite core. Nano composite section has been composed of undirectional E glass 409 g/m2، resin CY 219، hardner HY 5161 and nanoclay closite 30B dispersed into the epoxy system in a 0%، 4%، 7% and 10% ratio in weight with respect to the matrix. All panels fabricated using laid-up method in fiber volume fraction of 60%. Ballistic tests were conducted using Gas gun at the velocity of 205 and 225 m/s. The results of the ballistic impact experiments show that the amount of Specific energy absorption variations in 4% of nanoclay content is insignificant. However، in nanoclay contents of 7% and 10%، the Specific energy absorption increases. To analyze the results of the ballistic impact on the GLARE، the effect of nanoclay on the longitudinal and transversal mechanical properties of the composite was investigated. A noticeable correlation was found between ballistic impact results and Changes of toughness in longitudinal and transversal direction.