scholarly journals The Resistance of Ship Web Girders in Collision and Grounding

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Zhenguo Gao ◽  
Song Yang ◽  
Zhiqiang Hu
Keyword(s):  
Numerical Simulation ◽  
Analytical Method ◽  
Previous Experiment ◽  
Deformation Model ◽  
Deformation Characteristics ◽  
Concentrated Load ◽  
Reliable Assessment ◽  
Comparison Results ◽  
Simulation Based ◽  
Simulation Results

Ship web girders play an important role in ship structure performance during collision and grounding accidents. The behavior of web girders subjected to in-plane concentrated load is investigated by numerical simulation and theoretical analysis in this paper. A numerical simulation based on previous experiment is conducted to give insight to the deformation mechanism of crushing web girders. Some new important deformation characteristics are observed through the simulation results. A new theoretical deformation model is proposed featured with these deformation characteristics, and a simplified analytical method for predicting the instantaneous and mean resistances of crushing web girders is proposed. The proposed method is verified by two previous experiments and a series of numerical simulations. The agreement between the solutions by the proposed method and the experiment results is good. The comparison results between the proposed analytical method and numerical simulation results are satisfactory for most cases. The proposed analytical method will contribute to the establishment of an efficient method for fast and reliable assessment of the outcome of ship accidental collisions and grounding events.

Numerical Simulation on Thixo-Forging of Magnesium Matrix Composite

2011 ◽  
Vol 189-193 ◽  
pp. 2535-2538 ◽  
Author(s):  
Hong Yan ◽  
Wen Xian Huang
Keyword(s):  
Numerical Simulation ◽  
Matrix Composite ◽  
Metal Flow ◽  
Magnesium Matrix Composite ◽  
Magnesium Matrix ◽  
Simulation Based ◽  
Prior Literature ◽  
Simulation Results ◽  
Computer Numerical Simulation ◽  
Good Agreement

The thixo-forging of magnesium matrix composite was analyzed with computer numerical simulation based on rigid viscoplastic finite element method. The constitutive model of SiCp/AZ61 composite was established in our prior literature. Behavior of metal flow and temperature field were obtained. The differences between traditional forging and thixo-forging processes were analyzed. Results indicated that thixo-forging was better in filling cavity than forging. Simulation results were good agreement with experimental ones.

Study on flow field of gas–solid two-phase pulsed jet

2019 ◽  
Vol 33 (24) ◽  
pp. 1950279
Author(s):  
Xinhua Song ◽  
Xiaojie Li ◽  
Yang Wang ◽  
Honghao Yan
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Particle Distribution ◽  
Starch Granule ◽  
Injection Pressure ◽  
Two Phase ◽  
Particle Injection ◽  
Pulsed Jet ◽  
Simulation Based ◽  
Simulation Results

In this paper, a computational fluid dynamics–discrete element method (CFD–DEM) coupling method is established to simulate the starch granule injection by coupling CFD and DEM. Then a gas–solid two-phase pulsed jet system is designed to capture the flow field trajectory of particle injection (colored starch with a mean diameter of 10.67 [Formula: see text]m), and the image is processed by color moment and histogram. Finally, the simulation results are compared with the experimental results, and the following conclusions are drawn. The numerical simulation results show that with the increase of injection pressure, the injection height increases gradually. When the injection pressure reaches above 0.4 MPa, the increase of injection height decreases. The experimental images show that the larger the pressure (i.e., the greater the initial velocity), the faster the velocity of particle distribution in the space, and the injection heights with the injection pressures of 0.4 MPa and 0.5 MPa are close, which is consistent with the result from the FLUENT numerical simulation based on CFD–DEM.

Temperature distribution simulations during electron beam freeform fabrication process based on the fully threaded tree

2019 ◽  
Vol 25 (6) ◽  
pp. 989-997
Author(s):  
Yajun Yin ◽  
Wei Duan ◽  
Kai Wu ◽  
Yangdong Li ◽  
Jianxin Zhou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Temperature Distribution ◽  
Design Methodology ◽  
Content Type ◽  
Freeform Fabrication ◽  
Simulation Based ◽  
Simulation Results

Purpose The purpose of this study is to simulate the temperature distribution during an electron beam freeform fabrication (EBF3) process based on a fully threaded tree (FTT) technique in various scales and to analyze the temperature variation with time in different regions of the part. Design/methodology/approach This study presented a revised model for the temperature simulation in the EBF3 process. The FTT technique was then adopted as an adaptive grid strategy in the simulation. Based on the simulation results, an analysis regarding the temperature distribution of a circular deposit and substrate was performed. Findings The FTT technique was successfully adopted in the simulation of the temperature field during the EBF3 process. The temperature bands and oscillating temperature curves appeared in the deposit and substrate. Originality/value The FTT technique was introduced into the numerical simulation of an additive manufacturing process. The efficiency of the process was improved, and the FTT technique was convenient for the 3D simulations and multi-pass deposits.

Efficiency Metallic Leading Edge Structure Bird Strike Resistant Design

2011 ◽  
Vol 338 ◽  
pp. 84-89 ◽  
Author(s):  
Mei Ying Zhao ◽  
Jing Jing Li
Keyword(s):  
Numerical Simulation ◽  
Absorption Rate ◽  
Leading Edge ◽  
Experimental Results ◽  
Structural Quality ◽  
Bird Strike ◽  
Edge Structure ◽  
Simulation Based ◽  
Simulation Results ◽  
Resistant Structure

This article investigated a new metallic leading edge bird strike resistant structure, using corrugate board as its enhanced component to absorb more bird kinetic energy. This structure was called as Corrugate Board Leading Edge (CBLE) structure. To verify the structure’s bird strike resistant ability, numerical simulation based on the LS-DYNA was carried out, and succeeding experiments were performed. However, the experimental results were not exciting. They were not as the simulation results we expected. The reasons were analyzed through this article. Finally a rivet-relative model was created considering the influence of riveting. This model was proved to be accurate by comparing with experimental results. Based on the analysis above, an Optimized CBLE (O-CBLE) structure was used to optimize the bird strike resistant ability, the energy absorption rate of O-CBLE structure increased 11.4% while the structural quality was only slightly increased.

Influence of Constraint Method of Elastic Diaphragm on Numerical Simulation of Pressure-Compensating Emitter

2021 ◽  
Vol 64 (2) ◽  
pp. 425-434
Author(s):  
Xueli Chen ◽  
Zhengying Wei ◽  
Caixiang Wei ◽  
Jinpeng Ma ◽  
Zhuo Chen
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Computation Time ◽  
Experimental Results ◽  
Deformation Characteristics ◽  
Structure Interaction ◽  
Contact Constraint ◽  
Flow Field Characteristics ◽  
Simulation Results ◽  
Constraint Method

HighlightsDeformation of the elastic diaphragm can affect the flow field characteristics of a pressure-compensating emitter.The contact constraint method’s simulation of the elastic diaphragm were consistent with its actual deformation.The contact constraint method can reduce the relative errors between simulated and experimental results.Abstract. Numerical simulation is an important method for revealing the working principle and optimizing the design of drip emitters. The hydraulic performance of pressure-compensating (PC) emitters is determined by the interaction between the elastic diaphragm and the flow field; therefore, correct deformation of the elastic diaphragm is one of the factors determining the accuracy of numerical simulation of PC emitters. This study investigated the effects of three constraint methods of the elastic diaphragm on the numerical simulation of PC emitters. The three methods were fully fixed constraint (FFC), upper surface fixed constraint (UFC), and contact constraint (CC). Fluid-structure interaction (FSI) simulation was used to analyze the deformation characteristics of the elastic diaphragm, the flow field characteristics, and the flow rate of the PC emitter. The simulated diaphragm deformation and flow rates were compared with the results of a visual experiment and a hydraulic performance experiment, respectively. The simulation results showed that the constraint method affected the diaphragm deformation and flow field of the PC emitter. In comparing the simulation results with the experimental results, the CC method had the highest accuracy among the three constraint methods, but an extremely long computation time was required. The FFC method had the lowest accuracy but required less computation time. The accuracy of the UFC method was lower than CC and higher than FFC, but its computation time decreased by 60.03% compared with CC. This study provides a foundation for further research on the numerical simulation and design of PC emitters. Keywords: Constraint method, Deformation characteristics, Flow field characteristics, Fluid-structure interaction, Visual experiment.

Investigation of Indoor Environment for a Data Center

2009 ◽  
Author(s):  
Lingcang Li ◽  
Yanlei Liu ◽  
Xiuling Wang ◽  
A. G. Agwu Nnanna
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Relative Humidity ◽  
Indoor Air ◽  
Data Center ◽  
Indoor Environment ◽  
Low Cost ◽  
Simulation Based ◽  
Simulation Results ◽  
Volume Method

Special indoor air environment requirements are needed for the data center, such as ambient temperature, airflow pattern, relative humidity and ozone concentration to maintain the reliability of a computer system. In this paper, a numerical simulation based on 3-D Finite Volume Method has been conducted for a data center at Purdue University Calumet. The purpose of the simulation is to find out the most effective and low-cost air condition system. Results for temperature, relative humidity distributions as well as velocity patterns are presented. Mesh independent studies are performed. Numerical results are validated by experimental data. Suggestions are given based on the simulation results for improving the indoor environment of the data center.

Study on Analysis of Deposits Highway Slope Stability and Treatment

2011 ◽  
Vol 105-107 ◽  
pp. 1245-1249
Author(s):  
Yi Fang Feng ◽  
Hua Zhi Zhang
Keyword(s):  
Numerical Simulation ◽  
Slope Stability ◽  
Reduction Method ◽  
Strength Reduction ◽  
Strength Reduction Method ◽  
Deformation Characteristics ◽  
High Line ◽  
Geological Conditions ◽  
Deformation Features ◽  
Simulation Results

Taking Yangjiawuchang Bridge 2 Slope Project on the national key high line of Hangzhou to Lanzhou in China as example, the deformation characteristics of typical profile 4-4’ of the deposits highway slope project was studied by means of numerical simulation (FLAC3D). Based on the deformation fields, the slope deformation features were analyzed. According to the slope coefficient that was solved by strength reduction method, the slope stability was evaluated. In consideration of numerical simulation results and field geological conditions, the combination engineering treatments of surface drainage, paring-earthwork and unloading and slope temporary protection were selected. Moreover, the paring-earthwork areas were calculated and optimized. The simulation results can be based on to guide the engineering treatment, meanwhile, the results can provide reference for the similar engineering.

Numerical Simulation on Mechanical Ventilation for Odor Removal Efficiency in a Bathroom

2011 ◽  
Vol 243-249 ◽  
pp. 4877-4882
Author(s):  
Yiin Kuen Fuh ◽  
Wei Chi Huang
Keyword(s):  
Numerical Simulation ◽  
Mechanical Ventilation ◽  
Removal Efficiency ◽  
Previous Experiment ◽  
Change Rate ◽  
Air Change Rate ◽  
Odor Removal ◽  
Simulation Results ◽  
Ventilation Rates ◽  
Air Vent

This paper numerically studies the effect of ventilation rates and bathroom equipment locations on the odor removal efficiency in a modeled bathroom. Simulation results agree well with previously published experiments such that moving exhaust air vent from ceiling to wall and addition of one supply fan would significantly improve odor removal efficiency. In addition, by doubling the area of exhaust vent under a fixed air change rate, odor removal efficiency (ORE) can be greatly enhanced to 16-30% while previous experiment showed only a moderate 4% increase in ORE when doubled the flow rate of supply air.

Local Tribological Characteristics of Steel Sheets for Microforming

2013 ◽  
Vol 586 ◽  
pp. 116-119 ◽  
Author(s):  
Emil Evin ◽  
Miroslav Tomáš ◽  
Marek Výrostek ◽  
Vladimír Semjon
Keyword(s):  
Numerical Simulation ◽  
Contact Pressure ◽  
Deep Drawing ◽  
Contact Loading ◽  
Steel Sheets ◽  
Drawing Die ◽  
Micro Deep Drawing ◽  
Simulation Based ◽  
Simulation Results ◽  
O 15

The die radius represents the important local part of drawing die due to transferring contact loading under deep drawing. Within the experiments local contact pressure on die radius was researched using numerical simulation of strip drawn test and micro deep-drawing. Experimental research of strip drawn test was done using coatings with different alloying – under alloyed, optimal and slightly pre alloyed. Alloying level was evaluated by phase composition and % Fe in coating. Presented coatings were created on IF steel sheet DX54D. Experimental results of strip drawn test were used to verify strip-drawn test numerical simulation. Based on numerical simulation results, contact pressure on drawing die radius at deep drawing of cups Ø 50 mm and Ø 15 mm were observed.

Study on the Deformation Characteristics of Supporting System of Deep Foundation Pit in Subway Station Construction

2011 ◽  
Vol 243-249 ◽  
pp. 546-551
Author(s):  
Hua Zhi Zhang ◽  
Yi Fang Feng
Keyword(s):  
Numerical Simulation ◽  
Horizontal Displacement ◽  
Subway Station ◽  
Deformation Characteristics ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Deep Foundation Pit ◽  
Supporting System ◽  
Simulation Results ◽  
Metro Project

Taking Jiyu Bridge Station of Wuhan Metro Project as example, the deformation characteristics of supporting system of deep foundation pit was studied by means of numerical simulation (FLAC3D) in consideration of construction order. The deformation fields of different excavation depths of diaphram wall were obtained and analyzed in order to gain the maximum horizontal displacement value and settlement value. By comparison with the monitoring data, the simulation results can basically reflect the deformation characteristics. Moreover, the simulation results showed that the application of diaphram wall was feasible for foundation pit supporting in Jiyu Bridge Station, meanwhile, the results can be based on to guide the construction.

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