Interaction Assessment of Diagonally-Spaced Identical Corrosion Defects and Fully-Aligned Unequal-Sized Corrosion Defects Under Combined Loads

2021 ◽  
Author(s):  
Shulong Zhang ◽  
Wenxing Zhou
Keyword(s):  
Finite Element ◽  
Internal Pressure ◽  
Oil And Gas ◽  
Three Dimensional ◽  
Element Model ◽  
Interaction Effects ◽  
Longitudinal Compression ◽  
Combined Loads ◽  
Corrosion Defects ◽  
The Finite Element Model

Abstract In this study, the interaction effects of closely-spaced corrosion defects on the burst capacity of oil and gas pipelines under combined internal pressure and longitudinal compression are investigated by using parametric three-dimensional elasto-plastic finite element analyses. Full-scale burst tests reported in the literature are used to validate the finite element model. It is observed that the interaction effects of diagonally-spaced defects on the burst capacity is strongly related to the overlapping portion of the defect width or circumferential spacing between the two defects. The analysis results indicate that the strongest interaction between diagonally-spaced defects under combined loads occurs if the defects have zero circumferential separation. The interaction weakens as the defects are more and more overlapped or separated circumferentially. It is also observed that the interaction effect associated with longitudinally- or circumferentially-aligned, unequal-sized corrosion defects is negligible under the internal pressure only or combined loads.

CT Based Three Dimensional Geometric Model of Cervical Spine

2013 ◽  
Vol 273 ◽  
pp. 588-592
Author(s):  
Zhi Yuan Yan ◽  
Dong Mei Wu ◽  
Li Tao Zhang ◽  
Jun Zhao
Keyword(s):  
Finite Element ◽  
Cervical Spine ◽  
Geometric Model ◽  
Three Dimensional ◽  
Element Model ◽  
Skeletal System ◽  
High Quality ◽  
Element Analysis ◽  
Dimensional Reconstruction ◽  
The Finite Element Model

In order to obtain high-quality analytical results of the finite element model, it is essential to construct a three dimensional geometric model. The paper reconstructed an accurate three dimensional geometric model of cervical spine segments (C4-C7). The process of reconstruction included three-dimensional reconstruction, smooth processing, contour generation, grid generation and fitting surface. Moreover, the result of reconstruction was evaluated ultimately. The model was validated to be smooth and reasonable, and could meet the requirements of finite element analysis. The method is not merely applied to reconstruct the geometric model of the cervical spine. It is a way to construct the model of the skeletal system of the human body.

Simulation of Behaviors of a One-Third Scale Containment Model Test

2017 ◽  
Author(s):  
Guopeng Ren ◽  
Rong Pan ◽  
Feng Sun
Keyword(s):  
Finite Element ◽  
Power Plant ◽  
Nuclear Power Plant ◽  
Finite Element Model ◽  
Internal Pressure ◽  
Nuclear Power ◽  
Element Model ◽  
Scale Model ◽  
Prestress Losses ◽  
The Finite Element Model

Reactor containment of a nuclear power plant is a structure to ensure the safety of nuclear power plant. It acts as the last barrier to prevent the release of radioactive materials from NPP during accidents. Finite element models were established to simulate a 1/3 scale model of a reactor containment building under leakage test pressure. General finite element software ANSYS were applied. The nonlinear behavior of containment materials, geometric were taken into account in the analysis. The reliability of the finite element model was verified through the comparison of theoretical analysis results with experimental results. In the ANSYS finite element model, the concrete, steel bars and prestress tendons were separated and the prestress tendons were considered by the method of cooling method on the prestress tendon elements. The mechanical properties of the finite element model in the prestress tension process and the absolute internal pressure of 0.52MPa were analyzed. Transient and time dependent losses were taken into account at the same time during the calculation of prestress of tendons, so as to calculate effective prestress at different locations of tendons. Calculation results of prestress losses show that the prestress losses at the hole of equipment hatch are larger than the other areas. The results show that, the deformation of over-all structure of the containment is shrink inward under the action of prestress. And the simulation can achieve the consistent deformation effect between tendons and concrete. The maximum radial displacement of the whole containment structure is located at of 10 ° ∼ 20 °area on the right of the hole of the gate. The effect of expansion deformation of the containment caused by design internal pressure is insufficient to offset the inward shrink effect generated by tendons, and the over-all structure of the concrete containment scale model is mainly under compressive stress. The containment test model is still with a large safety margin under the action of design internal pressure. The largest tensile stress is on the up and down areas of the internal sides of the equipment hatch, dome area close to ring beam, and bottom of perimeter wall close to the base slab. There is possibility of cracking on the concrete in limited local zones. This benchmark can provide a reference for engineering design of containment.

Modeling of the Holding Force in an Electromagnetic Chuck

1999 ◽  
Vol 122 (3) ◽  
pp. 569-575 ◽  
Author(s):  
Alejandro Felix ◽  
Shreyes N. Melkote ◽  
Yoichi Matsumoto
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Prediction Errors ◽  
Modeling And Prediction ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Force Data ◽  
The Finite Element Model

This paper addresses the modeling and prediction of the normal holding force in an electromagnetic chuck used in precision machining applications. Knowledge of the normal holding force is necessary to determine if a given chuck is capable of preventing workpiece slip during machining. First, an analytic model termed the magnetic circuit model was developed and compared with experimental holding force data. It was found that this model, although simple in form, was limited in its ability to accurately predict the holding force over the entire range of conditions investigated. The discrepancies in the model were attributed to its inability to accurately model the leakage flux and nonuniform distribution of the magnetic flux. A three-dimensional finite element model was then developed to overcome these limitations. Predictions with this model were found to be in better agreement with experiments, yielding prediction errors within 25 percent in most cases. The finite element model also provided an explanation for the observed decrease in the measured holding force at current values beyond a certain threshold. [S1087-1357(00)01503-3]

Optimization Design of a New Heavy-Duty Self-Unloading Semi-Trailer

2011 ◽  
Vol 317-319 ◽  
pp. 2373-2377
Author(s):  
Guo Juan Shang ◽  
Gen Li Shan ◽  
Xi Juan Qi
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Optimization Design ◽  
Market Research ◽  
High Efficiency ◽  
Three Dimensional ◽  
Element Model ◽  
Loading Capacity ◽  
Heavy Duty ◽  
The Finite Element Model

Based on sufficient market research, a new model of self-unloading semi-trailer, whose maximum loading capacity is 30 tons, has been designed. The paper describes its overall structure, the three-dimensional diorama model and the finite element model of the frame. Based on the analysis of the models and the results of the calculation, the parameters of the frame are optimized. The advantages of the new design are as follows: the new design makes the most of the advantages of self-unloading trailers and semi-trailers, that is, self-unloading, security, stability, high efficiency, environmental protection.

Modal Analysis of Two Wheels Scooter Based on Solidworks

2014 ◽  
Vol 960-961 ◽  
pp. 1420-1423
Author(s):  
Zhi Dong Huang ◽  
Guo Fei Li ◽  
Juan Cong ◽  
Yun Wang ◽  
Wei Na Yu ◽  
...  
Keyword(s):  
Finite Element ◽  
Modal Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Dynamic Design ◽  
Driving System ◽  
Set Up ◽  
The Finite Element Model

Based on Solidworks software, the three-dimensional model of two wheels scooter is set up. The finite element model of two wheels scooter is generated. Modal analysis of driving system and telescopic mechanism of bar on two wheels scooter is investigated. The first five orders natural frequency and major modes of driving system and telescopic mechanism of bar are clarified. The method and the result can be used as a reference of dynamic design and lay foundation for calculation and analysis of dynamic response for the two wheels scooter.

The Application of Multi-Wedge Cross Wedge Rolling Forming Long Shaft Technology

2011 ◽  
Vol 101-102 ◽  
pp. 1002-1005 ◽  
Author(s):  
Jing Zhao ◽  
Li Qun Lu
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Finite Element Model ◽  
Rolling Mill ◽  
Three Dimensional ◽  
Element Model ◽  
Solid Model ◽  
The Finite Element Method ◽  
Cross Wedge Rolling ◽  
The Finite Element Model

The process of multi-wedge cross wedge rolling is an advanced precision technology for forming long shaft parts such as automobile semi-axes. Three-dimensional solid model and the finite element model of semi-axes on automobile and dies of its cross wedge rolling were established. The process of cross wedge rolling was simulated according to the actual dimension of semi-axes on automobile utilizing the finite element method (FEM)software ANSYS/LS-DYNA. The required force parameters for designing semi-axes mill are determined. The appropriate roller width was determined according to the length and diameter of semi-axes on automobile. The results have provided the basis for the design of specific structure of automobile semi-axes cross wedge rolling mill.

scholarly journals Analysis of historical structures by using finite element method in Iznik Yeşil Mosque

2019 ◽  
Vol 5 (4) ◽  
pp. 121
Author(s):  
Aykut Uray ◽  
Hasan Selim Şengel ◽  
Serdar Çarbaş
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Soil Survey ◽  
Three Dimensional Model ◽  
Historical Structures ◽  
Model Study ◽  
Non Destructive ◽  
The Finite Element Model

In this study, non-destructive tests and laboratory tests were carried out in order to determine the material properties in Iznik Yeşil Mosque, Iznik District, Bursa Province. For the purpose of determining the soil characteristics of the building, the soil survey studies conducted in the Iznik Yeşil Mosque area were investigated. The finite element model was formed by making a three dimensional model study of the structure. With the finite element model, static analysis, modal analysis and behavioral spectrum analysis were performed under vertical loads in order to collect data for the damaged areas of the structure.

A Burst Capacity Model for Corroded Pipelines Subjected to Combined Internal Pressure and Longitudinal Compression

2021 ◽  
Author(s):  
Shulong Zhang ◽  
Wenxing Zhou
Keyword(s):  
Internal Pressure ◽  
Correction Factor ◽  
Oil And Gas ◽  
Large Set ◽  
Finite Element Analyses ◽  
Longitudinal Compression ◽  
Combined Loads ◽  
Capacity Model ◽  
Proposed Model ◽  
Semi Empirical

Abstract The present study proposes a new semi-empirical burst capacity model for corroded oil and gas pipelines under combined internal pressure and longitudinal compression. The proposed model evaluates the burst capacity of a corroded pipeline under combined loads as the burst capacity of the pipeline under internal pressure only, which is developed in a recently completed study, multiplied by a correction factor to account for the effect of the longitudinal compression. Extensive parametric elastoplastic finite element analyses (FEA) are carried out, the results of which are used as the basis to develop the correction factor as a function of the corrosion defect sizes and magnitude of the longitudinal compressive stress. The proposed model is validated by a large set of parametric FEA and full-scale burst tests reported in the literature, and is shown to provide marked improvements over two existing models, the DNV and RPA-PLLC models, for corroded pipelines under combined loads.

Estimates of Elastic Crack Opening Displacements of Slanted Through-Wall Cracks in Plate and Cylinder

2010 ◽  
Vol 132 (2) ◽  
Author(s):  
Nam-Su Huh ◽  
Do-Jun Shim ◽  
Yeon-Sik Yoo ◽  
Suhn Choi ◽  
Keun-Bae Park
Keyword(s):  
Finite Element ◽  
Crack Opening ◽  
Three Dimensional ◽  
Bending Moment ◽  
Element Model ◽  
Finite Element Analyses ◽  
Opening Displacement ◽  
Elastic Crack ◽  
Leak Before Break ◽  
The Finite Element Model

This paper provides tractable solutions for elastic crack opening displacement (COD) of slanted through-wall cracks in plates and cylinders. The solutions were developed via detailed three dimensional elastic finite element analyses. The COD values were calculated along the thickness at the center of the crack. As for the loading conditions, only remote tension was considered for the plates, whereas remote tension, global bending moment, and internal pressure were considered for the cylinders. The finite element model employed in the present analysis was verified by using existing solutions for a cylinder with an idealized circumferential through-wall crack. The present results can be used to evaluate leak rates of slanted through-wall cracks, which can be used as a part of a detailed leak-before-break analysis considering more realistic crack shape development.

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