scholarly journals Young’s Modulus of Polycrystalline Titania Microspheres Determined by In Situ Nanoindentation and Finite Element Modeling

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Peida Hao ◽  
Yanping Liu ◽  
Yuanming Du ◽  
Yuefei Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Deformation Mechanisms ◽  
Displacement Curve ◽  
Element Simulation ◽  
Nanoindentation Experiment ◽  
Force Displacement

In situ nanoindentation was employed to probe the mechanical properties of individual polycrystalline titania (TiO2) microspheres. The force-displacement curves captured by a hybrid scanning electron microscope/scanning probe microscope (SEM/SPM) system were analyzed based on Hertz’s theory of contact mechanics. However, the deformation mechanisms of the nano/microspheres in the nanoindentation tests are not very clear. Finite element simulation was employed to investigate the deformation of spheres at the nanoscale under the pressure of an AFM tip. Then a revised method for the calculation of Young’s modulus of the microspheres was presented based on the deformation mechanisms of the spheres and Hertz’s theory. Meanwhile, a new force-displacement curve was reproduced by finite element simulation with the new calculation, and it was compared with the curve obtained by the nanoindentation experiment. The results of the comparison show that utilization of this revised model produces more accurate results. The calculated results showed that Young’s modulus of a polycrystalline TiO2microsphere was approximately 30% larger than that of the bulk counterpart.

Application of Video-Assisted Tactile Sensor and Finite Element Simulation for Estimating Young’s Modulus of Porcine Liver

2015 ◽  
Vol 35 (4) ◽  
pp. 510-516 ◽  
Author(s):  
Marat Dosaev ◽  
Irina Goryacheva ◽  
Yuri Martynenko ◽  
Alexey Morozov ◽  
Fyodor Antonov ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Tactile Sensor ◽  
Porcine Liver ◽  
Video Assisted ◽  
Element Simulation

Determination and Validation of Gurson-Tvergaard Model Parameters for Finite Element Simulation of Small Punch Test

2015 ◽  
Vol 750 ◽  
pp. 59-68 ◽  
Author(s):  
Yan Yan Lu ◽  
Liang Chen ◽  
Kai Shu Guan
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Model Parameters ◽  
Displacement Curve ◽  
Small Punch Test ◽  
Test Technique ◽  
Small Punch ◽  
Punch Test ◽  
Element Simulation ◽  
Load Displacement

Small punch test (SPT) is a miniature sample test technique which can evaluate in-service material properties with an almost non-destructive method. Since the deformation behavior of the small punch specimen is complicated, finite element simulation embedded with Gurson-Tvergaard (GTN) model is adopted to simulate elastic-plastic behaviour until fracture. Choosing the proper GTN parameters is crucial for the small punch simulation, which directly influence the precision of load-displacement curve obtained from simulation. In this paper, load-displacement curve is divided into five stages and the parameters identification process is done by adjusting the simulation curve with experimental load-displacement curve in different stages which controlled by separately parameters. The results show that the parameters determined based on this criterion are not unique. In order to validate the reliability of this method, specimen’s minimum thickness of cross-section after fracture was introduced as an extra criterion which turned out to be feasible. Load-displacement curves cannot serve as the only criterion to verify the GTN parameters.

scholarly journals The elastic-plastic properties of an anti-icing coating on an aluminum alloy: Experimental and numerical approach

2021 ◽  
Vol 30 (1) ◽  
pp. 1-8
Author(s):  
Wei Zhang ◽  
Sheng-Li Lv ◽  
Xiaosheng Gao ◽  
Tirumalai S. Srivatsan
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Numerical Approach ◽  
Nanoindentation Test ◽  
Strain Hardening Exponent ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Element Simulation ◽  
Nanoindentation Experiment ◽  
Numerical Finite Element

Abstract In this paper, an attempt is made to describe the method that combines the results obtained from nanoindentation experiment with finite element simulation to determine or establish the elastic-plastic properties of a super-hydrophobic anti-icing coating. The nanoindentation test was conducted and elastic properties of the coating, to include elastic modulus and hardness were obtained. The plastic properties, to include yield stress, monotonic strength coefficient and monotonic strain hardening exponent, were obtained using an inverse, iterative method of experimental measurement in synergism with finite element simulation. This approach, which is a combination of experimental data obtained from the nanoindentation test and results obtained from numerical finite element simulation, was found to be effective for determining mechanical properties of the chosen coating.

scholarly journals Modelling of Crack Propagation in Layered Structures Using Extended Finite Element Method

2016 ◽  
Vol 2 (5) ◽  
pp. 180-188 ◽  
Author(s):  
Hesamoddin Nasaj Moghaddam ◽  
Ali Keyhani ◽  
Iman Aghayan
Keyword(s):  
Finite Element Method ◽  
Crack Initiation ◽  
Crack Propagation ◽  
Young’S Modulus ◽  
Extended Finite Element Method ◽  
Young's Modulus ◽  
Displacement Curve ◽  
Extended Finite Element ◽  
Three Point Bending ◽  
Force Displacement

Crack propagation in structures is an important issue which is engineers and designers should consider. Modeling crack propagation in structures and study the behavior of this phenomenon can give a better insight to engineers and designers for selecting the construction’s materials. Extended finite element method (XFEM) was used successfully in the past few years for simulating crack initiation and propagation in sophisticated and complex geometries in elastic fracture mechanics. In this paper, crack propagation in three-point bending beam including initial crack was modeled based on ABAQUS software. The following consequences were attained through the study of simulation data. First, the effects of young’s modulus and fracture energy on force-displacement curve at three-point bending beam were investigated. It was observed that, by increasing the value of young’s modulus and fracture energy, three-point bending beam was showed more load carrying against initiation. Second, in multi-layer beam, the effect of young’s modulus on force-displacement curve was investigated. In case I (the thin upper layer is harder than the substrate) the value of young’s modulus in substrate was kept constant and the amount of young’s modulus in thin layer was risen in each step rather than the substrate, the peak in force-displacement curve was ascended and three-point bending beam resisted better against crack initiation. Next, similar conditions was considered in case II (the thin upper layer is softer than the substrate), by decreasing the value of young’ modulus in top layer, peak in force-displacement curve was declined and crack initiation was happened in lower loading in each step. Finally, sensitivity analysis for thickness of top layer was conducted and the impact of this parameter was studied.

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