scholarly journals New approach for getting better accuracy with mesh dependent material properties

Author(s):  
Qiu-Ping Zhou ◽  
Hua Ding

Based on the relationship between finite element (FE) solution and mesh size, a new approach based on mesh depending on the material properties is proposed to make the finite element analysis results more efficient and more close to the optimal solution. This optimal solution is often evaluated either by experiment or by finite element method (FEM). At the opposite of the accuracy obtained by sensitivities analysis of the FEM which requires time-consuming, our approach allows getting the optimal meshing based on the material properties.

2021 ◽  
Author(s):  
Muhammad Ardalani-Farsa

The finite element method has been applied in the area of the cervical spine since the 1970's. In the present research work, the finite element method was employed to model, validate and analyze a complete model of the human cervical spine from C1 to T1, including interconnecting intervertebral discs, ligaments and joints. The developed model of the cervical spine was validated by the experimental results presented in the literature. As the values obtained from the finite element analysis were mainly in the range of motion observed in the experiment; it was concluded that the finite element results were consistent with the reported data in the literature. Next, the validated model of the cervical spine was examined under physiological loading modes to locate the areas bearing maximum stress in the cervical spine. Finally, to study the effect of variations in the material properties on the output of the finite element analysis, a material property sensitivity study was conducted to the C3-T1 model of cervical spine. Changes in the material properties of the soft tissues affected the external and internal responses of both the hard and soft tissue components, while changes in those of the hard tissues only affected the internal response of hard tissues.


2021 ◽  
Author(s):  
Muhammad Ardalani-Farsa

The finite element method has been applied in the area of the cervical spine since the 1970's. In the present research work, the finite element method was employed to model, validate and analyze a complete model of the human cervical spine from C1 to T1, including interconnecting intervertebral discs, ligaments and joints. The developed model of the cervical spine was validated by the experimental results presented in the literature. As the values obtained from the finite element analysis were mainly in the range of motion observed in the experiment; it was concluded that the finite element results were consistent with the reported data in the literature. Next, the validated model of the cervical spine was examined under physiological loading modes to locate the areas bearing maximum stress in the cervical spine. Finally, to study the effect of variations in the material properties on the output of the finite element analysis, a material property sensitivity study was conducted to the C3-T1 model of cervical spine. Changes in the material properties of the soft tissues affected the external and internal responses of both the hard and soft tissue components, while changes in those of the hard tissues only affected the internal response of hard tissues.


2011 ◽  
Vol 213 ◽  
pp. 419-426
Author(s):  
M.M. Rahman ◽  
Hemin M. Mohyaldeen ◽  
M.M. Noor ◽  
K. Kadirgama ◽  
Rosli A. Bakar

Modeling and simulation are indispensable when dealing with complex engineering systems. This study deals with intelligent techniques modeling for linear response of suspension arm. The finite element analysis and Radial Basis Function Neural Network (RBFNN) technique is used to predict the response of suspension arm. The linear static analysis was performed utilizing the finite element analysis code. The neural network model has 3 inputs representing the load, mesh size and material while 4 output representing the maximum displacement, maximum Principal stress, von Mises and Tresca. Finally, regression analysis between finite element results and values predicted by the neural network model was made. It can be seen that the RBFNN proposed approach was found to be highly effective with least error in identification of stress-displacement of suspension arm. Simulated results show that RBF can be very successively used for reduction of the effort and time required to predict the stress-displacement response of suspension arm as FE methods usually deal with only a single problem for each run.


2019 ◽  
Vol 257 ◽  
pp. 02004
Author(s):  
Zhenhai Huang ◽  
Tingchun Shi ◽  
Xiuyan Yue

In view of the forming accuracy of the 3D printer, the paper, from the structure of the printer itself, discussed the influence on the precision of the printer via improving the structure of 3D printer. A typical 3D printer, such as a common type of FDM, was selected, and SOLIDWORKS software was used for solid modeling, after establishing the model, the finite element analysis was carried out on the whole structure model to obtain the deformation characteristics and the main vibration model of the printer. On the basis of finite element analysis, the influence of the level shaft bearing diameter, material properties and symmetry of the parts on the overall mechanical properties of the printer was discussed respectively. On this basis, the overall structure of the machine has been optimized and achieved remarkable results.


Author(s):  
Yasumasa Shoji ◽  
Toshiyuki Sawa ◽  
Hiroshi Yamanaka

As self-loosening of nuts is really a problem for bolted joints in practical use, countermeasures for the loosening is highly required. In this situation non-loosening fasteners are one of the resolutions for any fastened machinery as an essential mechanical element. Self-loosening of threaded bolt/nut systems has been researched in number of works and most researches were based on experiment and a few were based on the finite element analysis in these years. Using this new approach, various types of nuts can also be examined. Among these nuts eccentric nuts and slit nuts are especially expected to be the solution, as these nuts are reported to endure NAS vibration tests and were not loosened. In the authors’ previous paper, an eccentric nut and a normal nut were analyzed and compared in the aspect of loosening property. In this paper degree of loosening of various nuts was investigated by experiment and the FEA.


Author(s):  
Yuya Omiya ◽  
Tadatoshi Watanabe ◽  
Masahiro Fujii ◽  
Haruka Yamamoto

In this study, the creep deformation in the threaded joint are discussed using a finite element method, and evaluated the influence of the dimensions of bolt and clamped parts. The stress and creep strain distributions are calculated using the Finite Element Analysis. The occurrence and the propagation of the creep deformation and influence of the creep deformation on the axial bolt force were discussed. It was found that the creep deformation occurred at the bearing surfaces and the engagement screw thread mainly at the elevated temperature. The creep deformation was a cause of the reduction in axial bolt force.


2014 ◽  
Vol 525 ◽  
pp. 731-735 ◽  
Author(s):  
Qian Peng Han ◽  
Bo Peng

Finite element method(FEM) have been widely used in modern mechanical design,mesh generation is an important part of the finite element analysis,this article discussed the process of mesh generation through two practical cases and put forward some issues we should pay more attention to.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wencke Krings ◽  
Jordi Marcé-Nogué ◽  
Stanislav N. Gorb

AbstractThe radula, a chitinous membrane with embedded tooth rows, is the molluscan autapomorphy for feeding. The morphologies, arrangements and mechanical properties of teeth can vary between taxa, which is usually interpreted as adaptation to food. In previous studies, we proposed about trophic and other functional specialisations in taenioglossan radulae from species of African paludomid gastropods. These were based on the analysis of shape, material properties, force-resistance, and the mechanical behaviour of teeth, when interacting with an obstacle. The latter was previously simulated for one species (Spekia zonata) by the finite-element-analysis (FEA) and, for more species, observed in experiments. In the here presented work we test the previous hypotheses by applying the FEA on 3D modelled radulae, with incorporated material properties, from three additional paludomid species. These species forage either on algae attached to rocks (Lavigeria grandis), covering sand (Cleopatra johnstoni), or attached to plant surface and covering sand (Bridouxia grandidieriana). Since the analysed radulae vary greatly in their general size (e.g. width) and size of teeth between species, we additionally aimed at relating the simulated stress and strain distributions with the tooth sizes by altering the force/volume. For this purpose, we also included S. zonata again in the present study. Our FEA results show that smaller radulae are more affected by stress and strain than larger ones, when each tooth is loaded with the same force. However, the results are not fully in congruence with results from the previous breaking stress experiments, indicating that besides the parameter size, more mechanisms leading to reduced stress/strain must be present in radulae.


2015 ◽  
Vol 12 (3) ◽  
pp. 118-122 ◽  
Author(s):  
Tengfei Jiang ◽  
Chenglin Wu ◽  
Jay Im ◽  
Rui Huang ◽  
Paul S. Ho

In this article, the effects of Cu microstructure on the mechanical properties and extrusion of through-silicon vias (TSVs) were studied based on two types of TSVs with different microstructure. A direct correlation was found between the grain size and the mechanical properties of the vias. Both an analytical model and finite element analysis (FEA) were used to establish the relationship between the mechanical properties and via extrusion. The effect of via/Si interface on extrusion was also studied by FEA. The results suggest small and uniform grains in the Cu vias, as well as stronger interfaces between the via and Si led to smaller via extrusion, and are thus preferable for reduced via extrusion failure and improved TSV reliability.


2021 ◽  
Author(s):  
Wencke Krings ◽  
Jordi Marcé-Nogué ◽  
Stanislav N. Gorb

Abstract The radula, a chitinous membrane with embedded tooth rows, is the molluscan autapomorphy for feeding. The morphologies, arrangements and mechanical properties of teeth can vary between taxa, which is usually interpreted as adaptation to food. In previous studies, we proposed about trophic and other functional specialisations in taenioglossan radulae from species of African paludomid gastropods. These were based on the analysis of shape, material properties, force-resistance, and the mechanical behaviour of teeth, when interacting with an obstacle, which was previously simulated for one species (Spekia) by the finite-element-analysis (FEA) and, for more species, observed in experiments. In the here presented work, we test the previous hypotheses by applying the FEA on 3D modelled radulae, with incorporated material properties, from three additional paludomid species. These species forage either on algae attached to rocks (Lavigeria), covering sand (Cleopatra), or attached to plant surface and covering sand (Bridouxia). Since the analysed radulae vary greatly in their size between species, we additionally aimed at relating the simulated stress and strain distributions with the tooth sizes by altering the force/volume. For this purpose, we also included Spekia again in the present study. Our FEA results show that smaller radulae are more affected by stress and strain than larger ones, when each tooth is loaded with the same force. However, the results are not fully in congruence with results from the previous breaking stress experiments, indicating that besides the parameter size, more mechanisms leading to reduced stress/strain must be present in radulae.


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