Comparison of elastic properties of different shaped particle reinforced composites using micromechanics and finite element method

Author(s):  
P. Phani Prasanthi ◽  
K. Sivaji Babu ◽  
M. S. R. Niranjan Kumar ◽  
A. Eswar Kumar

In this work, differently shaped carbon nano-sized allotropes reinforced composite properties are estimated and interfacial stresses are calculated and compared to get the best carbon reinforcement. Carbon nanopowder, carbon nanotubes, nanographene and Buckminster fullerenes are selected as these materials have different shapes and reinforcement of these materials in the aluminium matrix will give different properties. The comparative studies are performed by using the Micromechanics and Finite element method. The longitudinal, transverse modulus, Poisson’s ratio are estimated along with the interface stresses between the constituents of carbon power/Al matrix composite, fullerene/Al matrix composite, CNT/Al matrix composite and graphene/Al matrix composite. From this work, it is found that the longitudinal modulus of the composite will be higher by using CNT or Graphene reinforcement and carbon particle or Buckminster fullerene reinforcement will give high transverse modulus than CNT and graphene reinforcement. The interfacial stresses generated between the reinforcement and the Aluminum matrix will be less by using carbon nanopowder than the other allotropes consider for the studies. This work will give an idea of the selection of nanoreinforcement of composite material in the perspective of elastic properties and interfacial stresses.

2011 ◽  
Vol 239-242 ◽  
pp. 2785-2789
Author(s):  
Chao Sun ◽  
Min Song ◽  
Ru Juan Shen ◽  
Yong Du

The effects of SiC fiber shape, aspect ratio and loading direction on the deformation behavior of SiC fiber reinforced Al matrix composites were studied by finite element method using axisymmetric unit cell model. The results showed that the addition of reinforcements will cause constraint on the plastic flow of ductile matrix, and thus result in no-uniform stress distribution. The reinforcement shape has a pronounced effect on the overall plastic deformation of the metal matrix composites. The loading condition will cause different failure mechanisms of composites. Under tensile loading, the stress-bearing ability in the plastic region is increased with the fiber aspect ratio due to the increase in the interface between the reinforcement and matrix and the decrease in the inter-particle space.


2011 ◽  
Vol 291-294 ◽  
pp. 606-609
Author(s):  
Li Qun Zhou ◽  
Yu Ping Li ◽  
Cai Ming Fu

A finite element method is used to simulate the deep drawing processes of nickel coating with steel substrate into battery shells. The Belytschko-Wong-Chiang shell elements are used and the kinematical work hardening model is adopted, while the ties with failure contact criterion is given to the coating and substrate interface. The stress-strain field and interfacial stresses in the drawing processes are obtained. The nickel coating appeared to be yielded in the drawing processes, of which the maximum effective stress reached 241MPa, and the biggest effective strain reached 0.7524. The interfacial stresses in the coating and substrate varied during the drawing process, and their maximal values reached 40MPa in compressive state.


Carbon ◽  
2018 ◽  
Vol 140 ◽  
pp. 210-217 ◽  
Author(s):  
Lubin Song ◽  
Zhangxin Guo ◽  
Gin Boay Chai ◽  
Zhihua Wang ◽  
Yongcun Li ◽  
...  

2020 ◽  
Author(s):  
Chiara Lanzi ◽  
Vincent Drouin ◽  
Siqi Li ◽  
Freysteinn Sigmundsson ◽  
Halldor Geirsson ◽  
...  

<p>The Krafla volcanic area in Northern Volcanic Zone of Iceland was characterized by deflation starting in 1989, suggesting a general pressure decrease and/or volume contraction at depth, which then exponentially decayed until having no significant deformation since around 2000.  In summer 2018, the volcano behaviour changed to inflation as observed both by Global Navigation Satellite System (GNSS) geodesy  and Sentinel-1 satellite radar interferometry (InSAR). Inflation since 2018 occurs at a rate of 10-14 mm/yr, centered in the middle of the caldera. No significant change in seismicity has occurred in the area in 2018, but seismic moment release ocurrs at a higher rate since middle 2019. Gravity stations in the area were remeasured in November 2019 for allowing comparison with earlier observations, and for providing reference for later studies. Initial modelling of the geodetic data is carried out assuming that the deformation is caused by a spherical source of pressure in an uniform elastic half-space. The result suggests that the deformation can be broadly explained by a single source of magma inflow at depth around 3.9-7.5 km, with the best-fit value around 4-4.5 km. We also apply the Finite Element Method (FEM) to additionally consider modification of the deformation field caused by Earth’s elastic heterogeneities and the uncertain geometry and  depth of the magma source. A set of FEM models are built with the COMSOL Multiphysics software in a 50x50 km domain where we test three different geometries of the source: a spherical source (radius 1000 km), a prolate ellipsoid,  and an oblate ellipsoid (sill-like) source, at 2.5, 4.0 and 5.5 km of depth. We also build a model to test how the vertical and horizontal displacements may be influenced by different elastic properties (e.g. Young’s modulus; about an order of magnitude different within a caldera boundary) for these sources. The results show that lateral variations in material properites can have a significant influence on ground deformation. Low-value Young’s inside caldera boundaries compared to higher values outside caldera boundaries will in particular influence the vertical displacement: the vertical displacement is about half of of what it is the original modelling.  The ratio of vertical to horizontal displacements will thus also be modified. This can in turn influence the inferred magma source geometry as it depends on the displacement ratios. The outcome of our study will provide better constrain for the elastic properties in Krafla area, and help understand the magma intrusion rate in the area.</p>


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