Evaluation of elastic properties of spread carbon fiber/epoxy laminates containing microcapsules by finite element method

2018 ◽  
Vol 2018 (0) ◽  
pp. J0430202
Author(s):  
Yasuka NASSHO ◽  
Kazuaki SANADA
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Carbon Fiber ◽  
Elastic Properties ◽  
Carbon Fiber Epoxy ◽  
Element Method

Numerical simulation of top roller pressure and deformation in ring spinning with three draft zones using finite element method

2016 ◽  
Vol 28 (2) ◽  
Author(s):  
Xiaojuan Zhang ◽  
Juan Wu ◽  
Bojun Xu ◽  
Xinjin Liu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Carbon Fiber ◽  
Design Methodology ◽  
Ring Spinning ◽  
Ansys Software ◽  
Yarn Quality ◽  
Cotton Yarns ◽  
Yarn Tenacity ◽  
Element Method

Purpose This paper presented a new kind of ring spinning frame with four pairs of rollers, and they are the front roller and the front top roller, the first middle roller (FMR) and the first middle top roller (FMTR), the second middle roller and the second middle top roller, the back roller and the back top roller. The FMR is the front roller of middle draft zone, and the back roller of the front draft zone. Therefore, the deformation of FMTR during spinning is an important factor for yarn quality, which was studied in this paper. Design/methodology/approach In this paper, by finite element method (FEM), the pressure and deformation of FMTR were studied. FMTR made from steel and sleeved carbon fiber were compared. 5.8tex, 4.9tex and 3.9tex cotton yarns were spun, and corresponding numerical simulations of FMTR pressure and deformation were presented in ANSYS software and comparatively analyzed. Then, corresponding yarn qualities were compared. Findings The results indicate that pressure and deformation of FMTR have little effects on yarn tenacity and hairiness, while have great effects on yarn evenness. For 5.8tex and 4.9tex cotton yarn, yarns spun by FMTR made from sleeved carbon fiber have larger pressure and deformation at the middle of nipper bites of FMR and FMTR, and yarn evenness is better. For 3.9tex cotton yarns, at the middle of nipper bites of FMR and FMTR, FMTR made from steel has smaller pressure. But deformation of FMTR made from steel is larger, and yarn evenness is better. Originality/value This paper studied pressure and deformation of FMTR by finite element method (FEM), which serve as a theoretical underpinning for yarn spinning in three draft zones ring spinning machine.

Three-phase micromechanical analysis of residual stresses in reinforced fiber by carbon nanotubes

2016 ◽  
Vol 51 (12) ◽  
pp. 1783-1794 ◽  
Author(s):  
Ahmad Reza Ghasemi ◽  
Mohammad Mohammadi Fesharaki ◽  
Masood Mohandes
Keyword(s):  
Finite Element Method ◽  
Carbon Nanotubes ◽  
Finite Element ◽  
Carbon Fiber ◽  
Residual Stresses ◽  
Representative Volume Element ◽  
Volume Element ◽  
The Finite Element Method ◽  
Representative Volume ◽  
Element Method

In this study, circular disk model and cylinder theory for two dimension (2D) and three dimension (3D), respectively, have been used to determine residual stresses in three-phase representative volume element. The representative volume element is consisting of three phases: carbon fiber, carbon nanotubes, and polymer matrix, that carbon fiber is reinforced by carbon nanotube using electrophoresis method. Initially, the residual stresses analysis of two-phase representative volume element has been implemented. The two-phase representative volume element has been divided to carbon fiber and matrix phases with different volume fractions. In the three-phase representative volume element, although the volume fraction of carbon fiber is constant and equal to 60%, the volume fractions of carbon nanotubes for various cases are different as 0%, 1%, 2%, 3%, 4%, and 5%. Also, there are two different methods to reinforce the fiber according to different coefficients of thermal expansion of the carbon fiber and carbon nanotube in two longitudinal and transverse directions; carbon nanotubes are placed on carbon fiber either parallel or around it like a ring. Subsequently, finite element method and circular disk model have been used for analyzing micromechanic of the residual stresses for 2D and then the results of stress invariant obtained by the finite element method have been compared with the circular disk model. Moreover, for 3D model, the finite element method and cylinder theory have been utilized for micromechanical analysis of the residual stresses and the results of stress invariant obtained by them, have been compared with each other. Results of the finite element method and analytical model have good agreement in 2D and 3D models.

A finite element method to investigate the elastic properties of pillared graphene sheet under different conditions

Carbon ◽  
2018 ◽  
Vol 140 ◽  
pp. 210-217 ◽  
Author(s):  
Lubin Song ◽  
Zhangxin Guo ◽  
Gin Boay Chai ◽  
Zhihua Wang ◽  
Yongcun Li ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Graphene Sheet ◽  
Elastic Properties ◽  
Element Method

Renewed Inflation of Krafla Caldera, Iceland, since 2018: Sensitivity of Ground Deformation to lateral variation in Earth structure and architecture of the magmatic system explored with the Finite Element Method

2020 ◽  
Author(s):  
Chiara Lanzi ◽  
Vincent Drouin ◽  
Siqi Li ◽  
Freysteinn Sigmundsson ◽  
Halldor Geirsson ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Elastic Properties ◽  
Ground Deformation ◽  
Vertical Displacement ◽  
Magma Source ◽  
The Finite Element Method ◽  
Spherical Source ◽  
Horizontal Displacements ◽  
Element Method

<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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