scholarly journals Finite Element Analysis on the Unloading Elastic Modulus of Aluminum Foams by Unit-cell Model

Author(s):  
F Triawan ◽  
B A Budiman ◽  
F B Juangsa ◽  
L A Prananto ◽  
M Aziz
2021 ◽  
pp. 073168442199086
Author(s):  
Yunfei Qu ◽  
Dian Wang ◽  
Hongye Zhang

The double V-wing honeycomb can be applied in many fields because of its lower mass and higher performance. In this study, the volume, in-plane elastic modulus and unit cell area of the double V-wing honeycomb were analytically derived, which became parts of the theoretical basis of the novel equivalent method. Based on mass, plateau load, in-plane elastic modulus, compression strain and energy absorption of the double V-wing honeycomb, a novel equivalent method mapping relationship between the thickness–width ratio and the basic parameters was established. The various size factor of the equivalent honeycomb model was denoted as n and constructed by the explicit finite element analysis method. The mechanical properties and energy absorption performance for equivalent honeycombs were investigated and compared with hexagonal honeycombs under dynamic impact. Numerical results showed a well coincidence for each honeycomb under dynamic impact before 0.009 s. Honeycombs with the same thickness–width ratio had similar mechanical properties and energy absorption characteristics. The equivalent method was verified by theoretical analysis, finite element analysis and experimental testing. Equivalent honeycombs exceeded the initial honeycomb in performance efficiency. Improvement of performance and weight loss reached 173.9% and 13.3% to the initial honeycomb. The double V-wing honeycomb possessed stronger impact resistance and better load-bearing capacity than the hexagonal honeycomb under impact in this study. The equivalent method could be applied to select the optimum honeycomb based on requirements and improve the efficiency of the double V-wing honeycomb.


10.2341/08-73 ◽  
2009 ◽  
Vol 34 (2) ◽  
pp. 223-229 ◽  
Author(s):  
A. O. Spazzin ◽  
D. Galafassi ◽  
A. D. de Meira-Júnior ◽  
R. Braz ◽  
C. A. Garbin

Clinical Relevance According to finite element analysis, the zirconia ceramic post created higher stress levels in the post and slightly less in dentin compared with glass fiber posts. Resin cement with a high elastic modulus created higher stress levels in the cement layer. The different film thicknesses of cement did not create significant changes in stress levels.


2020 ◽  
pp. 073168442093844 ◽  
Author(s):  
Navid Shekarchizadeh ◽  
Reza Jafari Nedoushan ◽  
Tohid Dastan ◽  
Hossein Hasani

This paper deals with investigating the tensile characteristics of biaxial weft-knitted reinforced composites in terms of stiffness, strength and failure mechanism. The biaxial weft-knitted fabric was produced on an electronic flat knitting machine by E-glass yarns and then was impregnated with epoxy resin. Using an accurate geometrical model, the composite unit cell was designed in Abaqus software’s environment. Tensile tests were simulated in different directions on the created unit cell and the stiffness was calculated. By applying the proper failure theories, the composite strength was predicted and then critical regions of the unit cell were determined. In the next step, a micromechanical approach was also applied to estimate the same tensile features. Failure theories were also applied to predict the strength and most susceptible areas for failure phenomenon in the composite unit cell. The tensile properties of the produced composites were measured and compared with outputs of the finite element and micromechanical approaches. The results showed that the meso-scale finite element analysis approach can well predict the composite strength. In contrast, the meso-scale analytical equation model was not able to predict it acceptably because this model ignores the strain concentration. Both meso-scale finite element analysis and meso-scale analytical equation approaches predicted the similar locations for the composite failure in wale and course directions.


Ceramics ◽  
2020 ◽  
Vol 3 (2) ◽  
pp. 210-222 ◽  
Author(s):  
Guenter Unterreiter ◽  
Daniel R. Kreuzer ◽  
Bernd Lorenzoni ◽  
Hans U. Marschall ◽  
Christoph Wagner ◽  
...  

Creep behavior is very important for the selection of refractory materials. This paper presents a methodology to measure the compressive creep behavior of fired magnesia materials at elevated temperatures. The measurements were carried out at 1150–1500 °C and under compression loads from 1–8 MPa. Creep strain was calculated from the measured total strain data. The obtained creep deformations of the experimental investigations were subjected to detailed analysis to identify the Norton-Bailey creep law parameters. The modulus of elasticity was determined in advance to simplify the inverse estimation process for finding the Norton-Bailey creep parameters. In the next step; an extended material model including creep was used in a finite element analysis (FEA) and the creep testing procedure was reproduced numerically. Within the investigated temperature and load range; the creep deformations calculated by FEA demonstrated a good agreement with the results of the experimental investigations. Finally; a finite element unit cell model of a quarter brick representing a section of the lining of a ferrochrome (FeCr) electric arc furnace (direct current) was used to assess the thermo-mechanical stresses and strains including creep during a heat-up procedure. The implementation of the creep behavior into the design process led to an improved prediction of strains and stresses.


2012 ◽  
Vol 568 ◽  
pp. 129-133
Author(s):  
Qian Yang ◽  
Jun Xing Zhang ◽  
Geng Ning Zhang

In this paper, we perform a 3D finite element analysis for the longitudinal settlement of a shield tunnel in soft soil, where a substratum soil contains a soft layer. The Mohr-Coulomb model is used for the substratum soil and soft layer. The longitudinal settlements are calculated for different elastic modulus and longitudinal length of the soft layer. The results show that a softer and longer layer will result in the larger settlement. It is also found that the maximum of the longitudinal settlements is linear function of the elastic modulus of the soft layer.


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