Evaluation of transverse thermal conductivity of Manila hemp fiber in solid region using theoretical method and finite element method

2011 ◽  
Vol 32 (8-9) ◽  
pp. 4586-4589 ◽  
Author(s):  
Ke Liu ◽  
Hitoshi Takagi ◽  
Zhimao Yang
2011 ◽  
Vol 675-677 ◽  
pp. 431-434
Author(s):  
Ke Liu ◽  
Hitoshi Takagi ◽  
Zhi Mao Yang

In order to evaluate the effect of natural fiber lumen size on the transverse thermal conductivity of the unidirectional natural fiber-polymer composite, a two-dimensional unit cell model of natural fiber-polymer composite was studied using finite element method (FEM). In this study, the FE cell model was kept in the steady state thermal condition. The results showed that the effective transverse thermal conductivity K has a relationship with the geometrical ratio (α, 0<α<1) of lumen radius (rl) to fiber radius (rf). When the lumen size ratio α is small, K increases with increasing fiber volume fraction Vf, while K decreases as the Vf increases when α is large. It indicates that the thermal property of composites changes with fiber’s lumen size. When a composite is designed for thermal insulation material, we should choose the natural fiber with large lumen, and to design thermal conductive composite, small lumen size should be used. The result from present method was compared with experimental data and shows a good agreement.


2021 ◽  
Vol 4 (2) ◽  
pp. 001
Author(s):  
Maurizio Ponte ◽  
◽  
Filippo Catanzariti ◽  
Gloria Campilongo

Computational simulation is widely used in companies to perform analysis and improve the quality of products and projects. Most of these analyses are carried out using software that uses the Finite Element Method, which allows to obtain answers to numerous engineering problems. In this study, two examples of application to the study of tunnels of the Finite Element Method using the Geostru Software "GFAS - Geotechnical F.E.M. Analysis System" are proposed. The case of a tunnel excavated inside a granite rock massif was analyzed, first determining the state of stresses in the cavity contour through a theoretical method and comparing these results with those obtained in the software. Then, by means of finite element modeling, the settlements induced by the excavation were determined. Finally, the problem of tunnel excavation in a viscoplastic rock mass is presented and the authors propose a comparison of the analytical and numerical method.


2007 ◽  
Vol 336-338 ◽  
pp. 1531-1533
Author(s):  
Jian Qiang Qi ◽  
Yong Huang ◽  
Shi Xi Ouyang ◽  
Nan Li ◽  
Jiang Li ◽  
...  

By means of a finite element method model, the effects of property parameters of refractory on thermal stress of injection lance have been studied. The results show that the maximum thermal stress increases with the improvement of thermal conductivity and elastic modulus of refractory, while it decreases at first and then increases with the improvement of the coefficient of expansion of refractory.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Nguyen Thai Chung ◽  
Nguyen Ngoc Thuy ◽  
Duong Thi Ngoc Thu ◽  
Le Hai Chau

In this paper, the authors present results on dynamic behavior analysis of the stiffened composite plate with piezoelectric patches under airflow by finite element method and experimental study. The first-order shear deformation plate theory and nine-noded isoparametric piezoelectric laminated plate finite element with five elastic degrees of freedom at each node and one electric degree of freedom per element per piezoelectric layer were used in the dynamic analysis of plates by finite element method. The modern equipment was used in the dynamic behaviors analysis of plates subjected to airflow load by experimental method. In this study, the results of the theoretical method have been compared with experimental studies.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
C. Mahesh ◽  
K. Govindarajulu ◽  
V. Balakrishna Murthy

Finite element method is effectively used to homogenize the thermal conductivity of FRP composites consisting of hybrid materials and fibre-matrix debonds at some of the fibres. The homogenized result at microlevel is used to determine the property of the layer using macromechanics principles; thereby, it is possible to minimize the computational efforts required to solve the problem as in state through only micromechanics approach. The working of the proposed procedure is verified for three different problems: (i) hybrid composite having two different fibres in alternate layers, (ii) fibre-matrix interface debond in alternate layers, and (iii) fibre-matrix interface debond at one fibre in a group of four fibres in one unit cell. It is observed that the results are in good agreement with those obtained through pure micro-mechanics approach.


Sign in / Sign up

Export Citation Format

Share Document