scholarly journals Computational Geometry-Based 3D Yarn Path Modeling of Wound SiCf/SiC-Cladding Tubes and Its Application to Meso-Scale Finite Element Model

2021 ◽  
Vol 8 ◽  
Author(s):  
Jianbo Tang ◽  
Gang Zhao ◽  
Jun Wang ◽  
Yue Ding ◽  
Yajie Feng ◽  
...  
Keyword(s):  
Finite Element ◽  
Nuclear Fuel ◽  
Element Model ◽  
Optimization Method ◽  
Filament Winding ◽  
Fe Model ◽  
Path Modeling ◽  
Fuel Cladding ◽  
Nuclear Fuel Cladding ◽  
Meso Scale

The filament winding process is a competitive performing technology for nuclear fuel cladding tubes due to its high automation. The study of the yarn path on the mandrel surface is vital to design and produce the cladding tube with the desired mechanical properties, reducing manufacturing time and costs. The geodesic and semi-geodesic trajectories are used to create a 3D yarn path in this paper. A 3D yarn path optimization method based on the principle of minimum potential energy is proposed to simulate the overlap effect in accord with the real winding process. The finite element (FE) mesh based on the 3D yarn path has been used for the mechanical analysis of the cladding tube. The embedded region constraint is applied to define the interaction between the matrix mesh and the yarn mesh to model the meso-structure of the cladding tube. Based on the meso-scale FE model, the mechanical behavior of the wound SiCf/SiC nuclear fuel cladding tube is studied in detail. The results show that due to the neglect of the overlap effect, the conventional laminate model overestimates the cladding tube strength. The proposed meso-scale FE model can accurately predict the failure of the cladding tube. The results also confirm that the creation of a 3D yarn path and the derived meso-scale FE model, representing an accurate wound structure, are of importance to the prediction of the performance of the cladding tube.

2D Meso-Scale Finite Element Modeling and Simulation of Polymer-Mineral Composite Material

2016 ◽  
Vol 848 ◽  
pp. 3-8
Author(s):  
Pei Yao Sheng ◽  
Shi Zhao Wang ◽  
Zhong Ji
Keyword(s):  
Finite Element ◽  
Composite Material ◽  
Numerical Analysis ◽  
Finite Element Modeling ◽  
Epoxy Resin ◽  
Element Model ◽  
Fe Model ◽  
Element Modeling ◽  
Low Thermal Expansion ◽  
Meso Scale

Polymer-mineral composite material is prepared by using modified epoxy resin as binder and mineral particles as aggregates. Its excellent damping characteristic and low thermal expansion make it ideal in manufacturing machine tool beds. However, the properties of this material depend on its formula and structure, so it is very important to develop an efficient method to numerically model the materials and then to optimize their properties. In this paper, 2D meso-scale finite element modeling is presented for numerical analysis of the mechanical properties of polymer-mineral composite material. The material was treated as a 2-phase composite composed of aggregates and binder which was epoxy resin mixed with fillers. Based on grading curve, the weights of aggregates were converted into the corresponding area, the aggregate particles were randomly generated and assembled with binder to produce the model. And then 2D numerical simulations were conducted under different gradations. The results show that: (1) the 2D FE model is very close to the real polymer-mineral composite material in the aspect of density and aggregate shapes and sizes, which validate the fidelity of the generated finite element model and numerical analysis method; (2) by comparing the materials’ properties under four different gradations, it can be found that the materials with SAC gradation have the best mechanical property.

Multiscale Modeling of SiCf/SiC Nuclear Fuel Cladding Based on FE-Simulation of Braiding Process

2021 ◽  
Vol 7 ◽  
Author(s):  
Yajie Feng ◽  
Jun Wang ◽  
Nianwei Shang ◽  
Gang Zhao ◽  
Chao Zhang ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Fe Simulation ◽  
Multiscale Model ◽  
Field Method ◽  
Phase Field Method ◽  
Fe Model ◽  
Fuel Cladding ◽  
Sic Fiber ◽  
The Matrix ◽  
Nuclear Fuel Cladding

A generalized multiscale (micro-macro) finite element (FE) model for SiC-fiber reinforced SiC-matrix ceramic (SiCf/SiC) nuclear fuel claddings is established. In the macro level, the solid mesh of braided preform, which can be tailored by machine settings (braid angle, yarn width, and so on), is generated based on the braiding process simulation using the dynamic FE-solver, hiring the contact constraints. The matrix mesh and the yarn mesh are integrated by the embedded region constraint, with which the meshing difficulties can be avoided. In the micro-UD model, the progressive damage of the ceramic matrix is modeled using the phase field method (PFM) and the fracture is captured by Mohr–Coulombs criterion, which are stable and efficient in the description of the brittle crack initiation, coalition, and branching. Based on this multiscale model, the mechanical behavior of the braided SiCf/SiC nuclear fuel cladding tube is studied in detail. The superiorities over the homogenized tube model are demonstrated, too.

scholarly journals Dynamic Finite Element Model Updating for On-load Tap Changer based on Super-model

2019 ◽  
Vol 256 ◽  
pp. 04001
Author(s):  
Zhiyuan Liu ◽  
Hongseng Zou ◽  
Miao Hui ◽  
Chen Dapeng ◽  
Guo Lin
Keyword(s):  
Finite Element ◽  
Dynamic Behavior ◽  
Model Updating ◽  
Element Model ◽  
Optimization Method ◽  
Simplified Model ◽  
Fe Model ◽  
Modeling And Analysis ◽  
Tap Changer ◽  
Load Tap Changer

A method is presented for dynamic model updating of on-load tap changer (OLTC). Based on a sensitivity-based optimization method, the initial simplified finite element (FE) model of OLTC component is updated using the analytical results of the FE super-model. The objective of model updating is to reduce the frequency difference between the simplified FE model and the super-model, and to make the simplified model accurately represent dynamic characteristics of the super-model. The updated simplified models can be further used in the modeling and analysis of the whole OLTC model. The results, taking the base of OLTC as example, indicate that the dynamic behavior of the updated simplified model match well with that of the super-model. Subsequently, the dynamic behavior of OLTC assembled with the updated parts is further predicted by modal analysis. The presented method improves the calculation efficiency, as well as accuracy, which has broad application prospects for dynamic prediction of complex structures in engineering.

Structural integrity of hydrided nuclear fuel cladding

2012 ◽  
Vol 1475 ◽  
Author(s):  
Jesús Ruiz-Hervías ◽  
F. Javier Gomez ◽  
Miguel A. Martín-Rengel ◽  
Elena Torres
Keyword(s):  
Nuclear Fuel ◽  
Structural Integrity ◽  
Element Model ◽  
Testing Temperature ◽  
Cohesive Crack ◽  
Crack Model ◽  
Fuel Cladding ◽  
Ring Compression ◽  
Different Temperatures ◽  
Nuclear Fuel Cladding

ABSTRACTThe structural integrity of nuclear fuel cladding is affected by the precipitation of hydrides during operation, which may embrittle the cladding. The aim of this work is to obtain the mechanical and fracture properties of the cladding as a function of the hydrogen content and testing temperature. To this end, the embrittlement caused by circumferential hydrides was simulated on unirradiated fuel cladding samples in the laboratory. The structural integrity of the cladding was assessed at different temperatures (20, 135 and 300ºC), by using the ring compression test. The mechanical properties and the fracture energy were calculated from the experimental load vs. displacement curves, by means of a finite element model which incorporates the cohesive crack model.

Finite Element Analysis of the Distributed Vibration Absorbers for Structural Noise Control

2005 ◽  
Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Base Plate ◽  
Element Model ◽  
Fe Model ◽  
Vibration Absorbers ◽  
Element Analysis ◽  
Poroelastic Media ◽  
Hexahedral Elements ◽  
Component Models

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.

Reverse Modeling and Topological Optimization for Lightweight Design of Automobile Wheel Hubs with Hollow Ribs

2019 ◽  
Vol 17 (09) ◽  
pp. 1950064
Author(s):  
P. F. Xu ◽  
S. Y. Duan ◽  
F. Wang
Keyword(s):  
Finite Element ◽  
Lightweight Design ◽  
Element Model ◽  
Optimization Method ◽  
Modeling Technique ◽  
Topological Optimization ◽  
Time Interval ◽  
Braking Performance ◽  
Existing Structures ◽  
Physical Conditions

Lightweight of wheel hubs is the linchpin for reducing the unsprung mass and improving the vehicle dynamic and braking performance of vehicles, thus, sustaining stability and comfortability. Current experience-based lightweight designs of wheel hubs have been argued to render uneven distribution of materials. This work develops a novel method to combine the reverse modeling technique with the topological optimization method to derive lightweight wheel hubs based on the principles of mechanics. A reverse modeling technique is first adopted to scan and reproduce the prototype 3D geometry of the wheel hub with solid ribs. The finite element method (FEM) is then applied to perform stress analysis to identify the maximum stress and its location of wheel hub under variable potential physical conditions. The finite element model is then divided into optimization region and nonoptimized region: the former is the interior portion of spoke and the latter is the outer surface of the spoke. A topology optimization is then conducted to remove the optimization region which is interior material of the spokes. The hollow wheel hub is then reconstructed with constant wall thickness about 5[Formula: see text]mm via a reverse modeling technique. The results show that the reconstructed model can reduce the mass of 12.7% compared to the pre-optimized model. The present method of this paper can guarantee the optimal distribution of wheel hub material based on mechanics principle. It can be implemented automatically to shorten the time interval for optimal lightweight designs. It is especially preferable for many existing structures and components as it maintains the structural appearance of optimization object.

Finite Element Model of Human Cochlea Considering of the Helicotrema Size

2013 ◽  
Vol 456 ◽  
pp. 576-581 ◽  
Author(s):  
Li Fu Xu ◽  
Na Ta ◽  
Zhu Shi Rao ◽  
Jia Bin Tian
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Basilar Membrane ◽  
Round Window ◽  
Element Model ◽  
Oval Window ◽  
Fe Model ◽  
Cochlear Duct ◽  
Human Cochlea ◽  
Set Up

A 2-D finite element model of human cochlea is established in this paper. This model includes the structure of oval window, round window, basilar membrane and cochlear duct which is filled with fluid. The basilar membrane responses are calculated with sound input on the oval window membrane. In order to study the effects of helicotrema on basilar membrane response, three different helicotrema dimensions are set up in the FE model. A two-way fluid-structure interaction numerical method is used to compute the responses in the cochlea. The influence of the helicotrema is acquired and the frequency selectivity of the basilar membrane motion along the cochlear duct is predicted. These results agree with the experiments and indicate much better results are obtained with appropriate helicotrema size.

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