Finite element analysis of hydrogen effects on superelastic NiTi shape memory alloys: Orthodontic application

2018 ◽  
Vol 29 (16) ◽  
pp. 3188-3198 ◽  
Author(s):  
Wissem Elkhal Letaief ◽  
Aroua Fathallah ◽  
Tarek Hassine ◽  
Fehmi Gamaoun
Keyword(s):  
Finite Element ◽  
Coupled Model ◽  
Element Model ◽  
Orthodontic Wires ◽  
Niti Wire ◽  
Element Analysis ◽  
Finite Element Software ◽  
Orthodontic Wire ◽  
Niti Shape Memory Alloys

Thanks to its greater flexibility and biocompatibility with human tissue, superelastic NiTi alloys have taken an important part in the market of orthodontic wires. However, wire fractures and superelasticity losses are notified after a few months from being fixed in the teeth. This behavior is due to the hydrogen presence in the oral cavity, which brittles the NiTi arch wire. In this article, a diffusion-mechanical coupled model is presented while considering the hydrogen influences on the NiTi superelasticity. The model is integrated in ABAQUS finite element software via a UMAT subroutine. Additionally, a finite element model of a deflected orthodontic NiTi wire within three teeth brackets is simulated in the presence of hydrogen. The numerical results demonstrate that the force applied to the tooth drops with respect to the increase in the hydrogen amount. This behavior is attributed to the expansion of the NiTi structure after absorbing hydrogen. In addition, it is shown that hydrogen induces a loss of superelasticity. Hence, it attenuates the role of the orthodontic wire on the correction tooth malposition.

Finite Element Analysis of the Effect of Surface Hardening Depth in Port Crane Wheel

2011 ◽  
Vol 291-294 ◽  
pp. 3282-3286 ◽  
Author(s):  
Jiang Wei Wu ◽  
Peng Wang
Keyword(s):  
Finite Element ◽  
Surface Hardening ◽  
Three Dimensional ◽  
Element Model ◽  
Contact Stresses ◽  
Numerical Results ◽  
Element Analysis ◽  
Finite Element Software ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In port crane industry, the surface hardening technique is widely used in order to improve the strength of wheel. But the hardening depth is chosen only by according to the experience, and the effect of different hardened depths is not studied theoretically. In this paper, the contact stresses in wheel with different hardening depth have been analyzed by applying three-dimensional finite element model. Based on this model, the ANSYS10.0 finite element software is used. The elastic wheel is used to verify the numerical results with the Hertz’s theory. Three different hardening depths, namely 10mm, 25mm and whole hardened wheel, under three different vertical loads were applied. The effect of hardening depth of a surface hardened wheel is discussed by comparing the contact stresses and contact areas from the numerical results.

Finite Element Analysis of X-Cor Sandwich's Compressive Strength

2011 ◽  
Vol 306-307 ◽  
pp. 733-737
Author(s):  
Xu Dan Dang ◽  
Xin Li Wang ◽  
Hong Song Zhang ◽  
Jun Xiao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compressive Strength ◽  
Failure Modes ◽  
Failure Mechanisms ◽  
Element Model ◽  
Failure Criteria ◽  
Stiffness Degradation ◽  
Element Analysis ◽  
Finite Element Software

In this article the finite element software was used to analyse the values for compressive strength of X-cor sandwich. During the analysis, the failure criteria and materials stiffness degradation rules of failure mechanisms were proposed. The failure processes and failure modes were also clarified. In the finite element model we used the distributions of failure elements to simulate the failure processes. Meanwhile the failure mechanisms of X-cor sandwich were explained. The finite element analysis indicates that the resin regions of Z-pin tips fail firstly and the Z-pins fail secondly. The dominant failure mode is the Z-pin elastic buckling and the propagation paths of failure elements are dispersive. Through contrast the finite element values and test results are consistent well and the error range is -7.6%~9.5%. Therefore the failure criteria and stiffness degradation rules are reasonable and the model can be used to predict the compressive strength of X-cor sandwich.

Finite Element Analysis of Frame of Dump Truck

2015 ◽  
Vol 733 ◽  
pp. 591-594
Author(s):  
Yong Zhen Zhu ◽  
Kuo Yang ◽  
Qi Yang ◽  
Yun De Zhao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
3D Model ◽  
Element Model ◽  
Dump Truck ◽  
Stress Distributions ◽  
Improved Method ◽  
Element Analysis ◽  
Finite Element Software ◽  
The Finite Element Model

The CAD software was used to establish 3D model of frame of dump truck, and the finite element model was established through Hyper Mesh. The stress distributions of the frame in vertical accelerating, turning, twisting and climbing conditions were computed through finite element software when the dump truck was loaded 80t. The result is consistent with the actual situation of the frame, which proved that the approach of finite element analysis is feasible. And we proposed the improved method of the frame according to finite element results.

Finite Element Analysis on Different Axial Compression Ratio of Composite CFST Column and Steel Beam Connection

2014 ◽  
Vol 578-579 ◽  
pp. 278-281
Author(s):  
Pi Yuan Xu ◽  
Qian Chen ◽  
Ya Feng Xu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Bearing Capacity ◽  
Axial Compression ◽  
Compression Ratio ◽  
Element Model ◽  
Element Analysis ◽  
Finite Element Software ◽  
Axial Compression Ratio ◽  
Modeling Process

In this paper, in order to understand fully the development of failure mechanism, bearing capacity and seismic performance of the steel H-beams and composite concrete filled steel tubular (CFST) column joints strengthened by outside strengthening ring, in the space zone the effects of changing the axial compression ratio is investigated. A 3D joint finite element model is built up by finite element software ABAQUS, the elastic-plastic finite element analysis is carried through numerical modeling process. The analysis results showed that low axial compression ratio has a little influence on the bearing capacity; with the increase of axial pressure the bearing capacity will decrease in a high axial compression ratio, moreover the failure pattern of joint changes from beam end to column end. The ductility of the specimens is decreased by raising axial compression ratio.

Finite Element Analysis to Vibratory Drum - Soil Model of Vibratory Roller

2011 ◽  
Vol 94-96 ◽  
pp. 2005-2008 ◽  
Author(s):  
Yuan Wen Cao ◽  
Xue Jiao Huang ◽  
Li Ying Ma ◽  
Sheng Qiu ◽  
Shao Xiong Gui
Keyword(s):  
Finite Element ◽  
Longitudinal Vibration ◽  
Soil Surface ◽  
Element Model ◽  
Element Analysis ◽  
Soil System ◽  
Linear Character ◽  
Finite Element Software ◽  
Vibration Compaction ◽  
The Finite Element Model

In this paper a dynamical equation about vibratory drum - soil system was set based on the non-linear character of vibration compaction of vibratory roller. The finite element model of vibratory drum - soil system was established by the finite element software ABAQUS, with which the vibration compaction process of vibratory drum is simulated. According to the analysis of the vibration propagation on the soil surface, the longitudinal vibration propagation of soil, the stress and strain of the soil under the vibratory drum, results have proved that it is valid to simulate the interaction between vibratory drum and soil by the nonlinear finite element method, which offered a new way to research the interaction between vibratory drum and soil.

Study of the Thermal-Structural Behavior of a Piston Diesel With Gallery Through Finite Element Method

2012 ◽  
Author(s):  
José Manuel Avila Aguilar ◽  
Raul Lesso Arroyo ◽  
Jorge Martínez Cruz
Keyword(s):  
Finite Element ◽  
Heat Flow ◽  
Interaction Analysis ◽  
The Body ◽  
Field Analysis ◽  
Element Analysis ◽  
Finite Element Software ◽  
Piston Head ◽  
The Finite Element Analysis

The finite element analysis is a useful tool to investigate the behavior of a body subjected to different loads. The objective of this work was the analysis of an aluminum diesel piston provided with a cooling gallery, Cu-Zn bushings, and a Ni-resist insert. This piston is used in 1.9 L turbodiesel engines. The investigation was undertaken in order to observe the mechanical behavior of the piston at the operating temperatures and pressures and thus to study the performance of the different parts of the piston. The analysis was performed using a finite element software, taking into account a coupled field analysis and involving a fluid passing through the cooling gallery, temperature and pressure at the piston head which resulted in heat flow and thermo-mechanical stresses in the piston. According to the obtained results, it is worth noting the important role of Cu-Zn bushings in the piston as they support the highest stress of about 359 MPa and protect the piston against failure, and these bushings are able to support more stress that the body of the piston (aluminum yield stress limit 290 MPa). Also it is observed that the cooling gallery acts as a thermal barrier by preventing the heat flow from the head piston (approximately 213 ° C) toward the piston body (approximately 80 ° C). Another important aspect is the structural thermal interaction analysis and it can be observed the influence of high temperatures in the piston, increasing stress up to 100%. Finally it was concluded that the piston is able to withstand the operating pressures and temperatures.

Stress and Strain Analysis of Composite Gas Cylinder Based on ABAQUS

2012 ◽  
Vol 557-559 ◽  
pp. 300-303
Author(s):  
Cheng Hong Duan ◽  
Xiang Peng Luo ◽  
Nan Zhang
Keyword(s):  
Finite Element ◽  
Strain Analysis ◽  
Element Model ◽  
Stress And Strain ◽  
Analysis Method ◽  
Element Analysis ◽  
Finite Element Software ◽  
Finite Element Analysis Method ◽  
Gas Cylinder ◽  
Gas Cylinders

In this paper, a finite element model of a composite gas cylinder was established by ABAQUS finite element software, with consideration that both heads were helically wound and their wound angle and wound thickness varied with different parallel circle radius. Stress of the composite gas cylinder and PEEQ of its liner under different working conditions after autofrettage treatment were studied, the stress distribution was assessed by the DOT CFFC standard and the effective range of autofrettage treatment was confirmed. This finite element analysis method may be referable to the design and inspection of composite gas cylinders.

Finite Element Analysis on Causes of Crack in Large Underground Garage

2014 ◽  
Vol 580-583 ◽  
pp. 1369-1376
Author(s):  
Bin Shu ◽  
Jian He Peng
Keyword(s):  
Finite Element ◽  
Poisson Ratio ◽  
Expansive Soil ◽  
Element Model ◽  
Underground Water ◽  
Element Analysis ◽  
Foundation Soil ◽  
Finite Element Software ◽  
Crack Problems ◽  
Set Up

The paper aims to solve the serious and regular crack problems in underground garage. ANSYS finite element software is applied to set up the overall finite element model on floor-foundation and foundation coupling beam-foundation soil in underground garage. Combined with engineering field detection, factors influencing underground garage floor like underground water level, soil expansion caused by water content change in expansive soil, soil poisson ratio, foundation settlement are taken into consideration to find out the causes of cracks. The study is expected to provide reference for similar cases in other projects.

Numerical Analysis on Superplastic Forming of Friction Stir Welded AA6061-T6 Alloy Sheet

2012 ◽  
Vol 488-489 ◽  
pp. 753-758 ◽  
Author(s):  
P. Ganesh ◽  
V.S. Senthil Kumar
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Constant Pressure ◽  
Pressure Coefficient ◽  
Superplastic Forming ◽  
Element Model ◽  
Alloy Sheet ◽  
Element Analysis ◽  
Friction Stir ◽  
Finite Element Software

The friction stir welded superplastic forming of AA6061-T6 sheet has been numerically analyzed based on the experimental and finite element software. A selected range of tool rotating speeds of 500, 1000 and 2000 rpm was used for friction stir welding. At constant temperature of 550O C and constant pressure of 0.4 Mpa, superplastic forming experiments was performed using free forming die for the friction stir welded sheets. A detailed 3D element type study has been performed in the finite element analysis. The proposed finite element model has been validated in comparison with experimental data. The results are found to have reasonably good agreement between simulations and experiment. The effect of constant pressure, coefficient of friction, strainrate and strain-rate sensitivity has been studied using the proposed finite element model.

Based on Analysis of Finite Element Analysis of Automobile Transmission Shaft Comprehensive Optimization

2014 ◽  
Vol 684 ◽  
pp. 341-346
Author(s):  
Heng Yi Yuan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
High Speed ◽  
Ride Comfort ◽  
Element Model ◽  
Drive Shaft ◽  
Element Analysis ◽  
Finite Element Software ◽  
Transmission Shaft

The shaft as an important parts of automobile transmission system, in the process of the car have the effect of rotational speed and torque. Due to the structural characteristics of its low frequency, small stiffness, universal joint, such as the existence of the additional moment drive shaft inevitably exist when high speed vibration phenomenon. So the shaft vibration problems to deal with the vehicle ride comfort, comfort and dynamic performance has important significance. On the basis of the finite element software ANSYS, the physical design of drive shaft. Analyzes the mapping grid finite element model of transmission shaft, facilitate accurate transmission shaft strength calculation. Based on the inherent frequency and vibration model of finite element method to calculate transmission shaft, using experimental modal technology for modal analysis of the shaft, the test results verify the reliability of the finite element model. On this basis, the drive shaft assembly constraint modal finite element analysis, can be used as the basis of further research.

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