scholarly journals Analytical and Finite Element Modeling of the Dynamic Characteristics of a Linear Feeding Stage with Different Arrangements of Rolling Guides

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jyh-Cheng Chang ◽  
Jui-Pin Hung
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Dynamic Characteristics ◽  
Element Model ◽  
Linear Guide ◽  
Element Modeling ◽  
Positioning Stage ◽  
The Finite Element Model

This study was aimed at investigating the dynamic behaviors of the linear driven feeding stage by means of the analytical and finite element modeling approaches. To assess the dynamic characteristics of the stages with different linear guide arrangements, the finite element model of the stages was created, in which the linear components with rolling interface were accurately modeled based on the Hertzian theory. On the other hand, the analytically mathematical model was derived to determine how the linear guide arrangement affects the dynamic characteristics of the stage. Results of the modal analysis show that the vibration behaviors of the positioning stage are dominated by the rigidity of the linear components and the platform. In addition, comparisons of the results from the two approaches further indicate that the platform rigidity is an important factor determining the accuracy of the prediction of the vibration frequencies by the analytically mathematical model. As a conclusion of the study, the analytically mathematical model can approximate well to the finite element model when the linear stage is designed with appropriate structure rigidity.

Finite Element Modeling Method of 3D Braided Composites Based on ICT Technique

2012 ◽  
Vol 236-237 ◽  
pp. 16-20
Author(s):  
Shu Yong Wang ◽  
Jian Fu ◽  
Qian Li Wang
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Composite Materials ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Element Model ◽  
Braided Composites ◽  
Element Modeling ◽  
3D Braided Composites ◽  
The Finite Element Model

A finite element modeling method based on industrial computed tomography (ICT) technique is proposed to address the insufficient accuracy of traditional grinding method for the meso-structure analysis of composite materials. In this method, the slice images of 3D composites are first acquired by ICT technique. And then, the internal meso-structure images of composite materials are obtained through the digital image processing to the slice images. Finally the meso-structure images are converted to vector format and inputted ANSYS to build the finite element model for the analysis of the mechanical properties. The experimental results show that this method can establish the finite element model and reveal the internal structure and the inherent mechanical properties of composite materials. These researches provide a reference for the manufacture processing of 3D braided composites, and the theoretical basis for the optimal design and performance evaluation. It would be of significance for the improvement of the composites mechanical properties.

Experimentally validated predictive finite element modeling of the V0-V100 probabilistic penetration response of a Kevlar fabric against a spherical projectile

2018 ◽  
Vol 9 (4) ◽  
pp. 504-524 ◽  
Author(s):  
Gaurav Nilakantan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Element Model ◽  
Ballistic Impact ◽  
Impact Testing ◽  
Woven Fabric ◽  
Projectile Impact ◽  
Element Modeling ◽  
The Impact

This work presents the first fully validated and predictive finite element modeling framework to generate the probabilistic penetration response of an aramid woven fabric subjected to ballistic impact. This response is defined by a V0-V100 curve that describes the probability of complete fabric penetration as a function of projectile impact velocity. The exemplar case considered in this article comprises a single-layer, fully clamped, plain-weave Kevlar fabric impacted at the center by a 0.22 cal spherical steel projectile. The fabric finite element model comprises individually modeled three-dimensional warp and fill yarns and is validated against the experimental material microstructure. Sources of statistical variability including yarn strength and modulus, inter-yarn friction, and precise projectile impact location are mapped into the finite element model. A series of impact simulations at varying projectile impact velocities is executed using LS-DYNA on the fabric models, each comprising unique mappings. The impact velocities and outcomes (penetration, non-penetration) are used to generate the numerical V0-V100 curve which is then validated against the experimental V0-V100 curve obtained from ballistic impact testing and shown to be in excellent agreement. The experimental data and its statistical analysis used for model input and validation, namely, the Kevlar yarn tensile strengths and moduli, inter-yarn friction, and fabric ballistic impact testing, are also reported.

Hydroelastic Modal Analysis of the Perforated Cylindrical Shell in SMART

2011 ◽  
Author(s):  
Youngin Choi ◽  
Seungho Lim ◽  
Kyoung-Su Park ◽  
No-Cheol Park ◽  
Young-Pil Park ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Element Model ◽  
Mode Shapes ◽  
Steam Generators ◽  
Structure Interaction ◽  
The Finite Element Model ◽  
Reactor Internals

The System-integrated Modular Advanced ReacTor (SMART) developed by KAERI includes components like a core, steam generators, coolant pumps, and a pressurizer inside the reactor vessel. Though the integrated structure improves the safety of the reactor, it can be excited by an earthquake and pump pulsations. It is important to identify dynamic characteristics of the reactor internals considering fluid-structure interaction caused by inner coolant for preventing damage from the excitations. Thus, the finite element model is constructed to identify dynamic characteristics and natural frequencies and mode shapes are extracted from this finite element model.

scholarly journals Analysis of dynamic characteristics of climbing formwork under wind loads

2019 ◽  
Vol 79 ◽  
pp. 01016
Author(s):  
Shicheng Hu ◽  
Jun Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Characteristics ◽  
Calculation Method ◽  
Design Method ◽  
Element Model ◽  
Wind Load ◽  
Bending Effect ◽  
Matlab Programming ◽  
The Finite Element Model

This article took the climbing formwork which constructed on the bridge at a height of 100 meters as the prototype, then established the finite element model and conducted modal analysis. The APDL language is used to load the wind load which is simulated by the Matlab programming then calculated the displacement and acceleration responses of the climbing formwork and further. The results show that the bending effect of the climbing formwork is more obvious. This calculation method of calculating the wind load, improve the anti-wind design method of the climbing formwork.

Modal Analysis of BT Spindle-Toolholder Interface Based on Abaqus/Standard

2013 ◽  
Vol 662 ◽  
pp. 632-636
Author(s):  
Yong Sheng Zhao ◽  
Jing Yang ◽  
Xiao Lei Song ◽  
Zi Jun Qi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Modal Analysis ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Element Model ◽  
Contact Theory ◽  
High Speed Machining ◽  
The Finite Element Model

The quality of high speed machining is directly related to dynamic characteristics of spindle-toolholder interface. The paper established normal and tangential interactions of BT spindle-toolholder interface based on finite element contact theory, and analysed free modal in Abaqus/Standard. Then the result was compared with the experimental modal analysis. It shows that the finite element model is effective and could be applied in the future dynamic study of high-speed spindle system.

BOUNDARY CONDITIONS IN FINITE ELEMENT MODELING OF STRATIFIED COASTAL CIRCULATION

1988 ◽  
Vol 1 (21) ◽  
pp. 190
Author(s):  
George C. Christodoulou ◽  
George D. Economou
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Coastal Waters ◽  
Stratified Flow ◽  
Element Model ◽  
Numerical Computations ◽  
Element Modeling ◽  
Sponge Layer

The effect of boundary conditions on numerical computations of stratified flow in coastal waters is examined. Clamped, free radiation and sponge layer conditions are implemented in a two-layer finite element model and the results of simple tests in a two-layer stratified basin are presented.

The effect of a localized fault in the planet bearing on vibrations of a planetary gear set

2018 ◽  
Vol 53 (5) ◽  
pp. 313-323 ◽  
Author(s):  
Jing Liu ◽  
Yajun Xu ◽  
Yimin Shao ◽  
Huifang Xiao ◽  
Hongwu Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Dynamic Characteristics ◽  
Rotational Velocity ◽  
Planetary Gear ◽  
Element Model ◽  
Previous Method ◽  
Outer Race ◽  
Velocity Moment ◽  
The Finite Element Model

Dynamic characteristics of a planetary gear set can be greatly affected by a localized fault in the planet bearing. To understand the relationship between the dynamic characteristic of the planetary gear set and the localized fault sizes, a dynamic finite element model for a planetary gear set is developed. A localized fault is assumed to be located in the outer race of the planet bearing. The fault profile is defined as a rectangular one. To formulate the elastic deformations of the components and elastic contact deformations between the mating components, all components of the planetary gear set are considered as elastic bodies in the finite element model. A standard gravity is also considered in the finite element model. A Coulomb frictional model is used to formulate the frictional forces in the planetary gear set. Influences of the rotational velocity, moment, and fault width on the dynamic characteristics of the planetary gear set are discussed. The simulation results are compared with those from the previous method to validate the finite element model. It seems that the presented finite element model can be applied to simulate the dynamic characteristics of a planetary gear set caused by a localized fault in the outer race of the planet bearing.

Finite element modeling to expand the UMCCA model to describe biofilm mechanical behavior

2005 ◽  
Vol 52 (7) ◽  
pp. 161-166 ◽  
Author(s):  
C.S. Laspidou ◽  
B.E. Rittmann ◽  
S.A. Karamanos
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Mechanical Behavior ◽  
Element Model ◽  
Internal Stresses ◽  
Active Biomass ◽  
Biofilm Model ◽  
Composite Solid ◽  
The Finite Element Model

In order to understand the influence of biofilm's physical and microbiological structures on its mechanical behavior, a finite element model that describes the structural mechanics of a composite solid is linked to the outputs of the multi-component biofilm model UMCCA. The UMCCA model outputs densities of active biomass, inert biomass, and EPS for each compartment in a 2-D biofilm. These densities are mapped to the finite-element model to give a composite Young's modulus, which expresses the stress-strain properties of the biofilm by location. Sample results illustrate that using this methodology, one can identify the points in the biofilm that develop the highest internal stresses and that are most likely to fail first, leading to detachment.

scholarly journals Three-dimensional finite element modeling for evaluation of laryngomalacia severity in infants and children

2020 ◽  
Vol 48 (6) ◽  
pp. 030006052092640
Author(s):  
Hongming Xu ◽  
Jiali Chen ◽  
Shilei Pu ◽  
Xiaoyan Li
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Three Dimensional ◽  
Element Model ◽  
3D Finite Element ◽  
Element Modeling ◽  
Laryngeal Cartilage ◽  
Computed Tomography Images

This study was performed to investigate the feasibility of using a three-dimensional (3D) finite element model for laryngomalacia severity assessment. We analyzed laryngeal computed tomography images of seven children with laryngomalacia using Mimics software. The gray threshold of different tissues was distinguishable, and a 3D visualization model and finite element model were constructed. The laryngeal structure parameters were defined. The peak von Mises stress (PVMS) value was obtained through laryngeal mechanical analysis. The PVMS values of the laryngeal soft tissue and cartilage scaffolds were independently correlated with disease severity. After stress loading the model, the relationship between laryngomalacia severity and the PVMS value was apparent. However, the PVMS value of laryngeal soft tissue was not correlated with laryngomalacia severity. This study established the efficacy of a finite element model to illustrate the morphological features of the laryngeal cavity in infants with laryngomalacia. However, further study is required before widespread application of 3D finite element modeling of laryngomalacia. PVMS values of the laryngeal cartilage scaffold might be useful for assessment of laryngomalacia severity. These findings support the notion that structural abnormalities of the laryngeal cartilage may manifest as quantifiable changes in stress variants of the supraglottic larynx.

Patient Specific Finite Element Modeling of a Human Skull

2006 ◽  
Vol 49 ◽  
pp. 227-234 ◽  
Author(s):  
Norio Inou ◽  
Michihiko Koseki ◽  
Koutarou Maki
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Image Data ◽  
Element Model ◽  
Biomechanical Study ◽  
Modeling Method ◽  
Patient Specific ◽  
Human Skull ◽  
Element Modeling

This paper presents automated finite element modeling method and application to a biomechanical study. The modeling method produces a finite element model based on the multi-sliced image data adaptively controlling the element size according to complexity of local bony shape. The method realizes a compact and precise finite element model with a desired total number of nodal points. This paper challenges to apply this method to a human skull because of its intricate structure. To accomplish the application of the human skull, we analyze characteristics of bony shape for a mandible and a skull. Using the analytical results, we demonstrate that the proposed modeling method successfully generates a precise finite element model of the skull with fine structures.

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