scholarly journals Dynamic Finite Element Analysis of a New Type Flexible Rock Shed under the Impact of Rock Block and Improving the Design

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Lianming Cui ◽  
Min Wang ◽  
Tangrong Yu
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Impact Analysis ◽  
Numerical Models ◽  
Element Model ◽  
Functional Evaluation ◽  
Element Analysis ◽  
Simulation Results ◽  
Improved Design ◽  
The Impact

A 1:1 flexible rock shed made of flexible nets and steel-vaulted structure is manufactured and tested for functional evaluation with impact experiment previously. To further discuss the performance of this structure under the impact of rockfalls and to improve the design, numerical simulation for this structure is carried out in this paper. Firstly, the simplified numerical models for characterizing the mechanical behavior of the ring nets and wire meshes are deduced. Then, a detailed finite element model for the flexible rock shed is developed for impact analysis. By comparing the experimental data, the numerical model for the flexible rock shed is shown to be reliable in predicting the dynamic behavior of the flexible rock shed. Finally, combined with the numerical simulation results and experimental results, an improved design is presented, and the numerical simulation results show that the energy dispersion in the improved design of the rock shed is more equalized, and damages on the steel-vaulted structure are much improved.

Finite Element Analysis of Contact Force Models During Solid Elastic and Plastic Bodies Impact

2018 ◽  
Author(s):  
Gustavo Simão Rodrigues ◽  
Hans Ingo Weber ◽  
Larissa Driemeier
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Contact Force ◽  
Numerical Models ◽  
Element Model ◽  
The Body ◽  
Element Analysis ◽  
Solid Bodies ◽  
The Impact ◽  
Element Method

There are many models of impact used to predict the post-impact conditions of a system and all of them are based on Hertz’s theory, dated from the nineteenth century, where the repulsive force is proportional to the deformation of the bodies under contact and may also be proportional to the rate of deformation. The objective of this work is to analyze the behavior of the bodies during impact using some contact models and compare the results to a Finite Element Method model. The main parameters which will be evaluated are the body velocities, the contact force and the deformation of the bodies. An advantage of using the Finite Element Method is the possibility to apply plastic deformation to the model according to material definition. In the present study, it will be used Johnson–Cook plasticity model where the parameters are obtained based on empirical tests of real materials. Thus, it is possible to compare the behavior of elastic and plastic numerical models with the finite element model and to verify how these models reproduce the impact between solid bodies.

Effect of Cracked Blade Distribution on Vibration Characteristics of Centrifugal Impeller

2013 ◽  
Vol 457-458 ◽  
pp. 556-559
Author(s):  
Gang Cheng ◽  
Jian Feng Li ◽  
Wei Qiang Wang ◽  
Jie Sun
Keyword(s):  
Finite Element ◽  
Centrifugal Force ◽  
Numerical Models ◽  
Element Model ◽  
Compressor Blade ◽  
Centrifugal Impeller ◽  
Element Analysis ◽  
Equilibrium Pressure ◽  
The Finite Element Analysis ◽  
Simulation Results

In this paper, the finite element analysis is made to the modal analysis of the impeller, a finite element model of a impeller with cracks was established. This paper presents results of the modal of the compressor blade subjected to centrifugal force and aerodynamic equilibrium pressure. In this analysis, the numerical models without defects and also with cracks were defined. The simulation results showed that the centrifugal force due to rotational speed can greatly influence the frequency of the impeller. The distribution of two cracked blades effect the natural frequence of the impeller. When two cracked blades locate in the interval position, the increasing value of frequence is maximum. When the two cracked blades interval 150°, the increasing value of frequence is minimum. It provides a basis for modal calculation of the impeller.

Nonlinear Dynamic Response of Buoys under the Collision Load with Ships

2012 ◽  
Vol 204-208 ◽  
pp. 4455-4459 ◽  
Author(s):  
Liu Hong Chang ◽  
Chang Bo Jiang ◽  
Man Jun Liao ◽  
Xiong Xiao
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Analysis Software ◽  
Element Analysis ◽  
Nonlinear Dynamic Response ◽  
Dynamic Finite Element ◽  
Simulation Results ◽  
Collision Force ◽  
Explicit Dynamic ◽  
Element Theory

The explicit dynamic finite element theory is applied on the collision of ships with buoys for computer simulation. Using ANSYS/LS-DYNA finite element analysis software, the numerical simulation of the collision between the ton ship and the buoy with different structures and impact points. The collision force, deformation, displacement parameters and the weak impact points of a buoy are obtained. Based on the numerical simulation results, analysis of buoys and structural collision damages in anti-collision features are discussed, and several theoretical sugestions in anti-collision for the design of buoy are provided.

Impact Analysis of an Oxygen Mask Locking Panel of Aircraft Using Finite Element Modelling

2014 ◽  
Vol 657 ◽  
pp. 735-739 ◽  
Author(s):  
Emilian Ionut Croitoru ◽  
Gheorghe Oancea
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Impact Analysis ◽  
Element Model ◽  
Composite Panel ◽  
Cad Model ◽  
Stress Variation ◽  
Element Modelling ◽  
Oxygen Mask ◽  
The Impact

This paper presents a method of finite element modelling used for the impact analysis of a composite panel. In this research, the composite panel consists of an oxygen mask locking panel of an aircraft. This panel is loaded with one concentrated abuse loading and three uniform distributed abuse loading cases and the stress variation within the composite panel for each load case is determined. In order to assess the impact analysis on the oxygen mask panel of the aircraft, a finite element model is created using Patran as the main application for pre/post-processing and Nastran as the main processor. The paper also presents a comparison between results obtained using the same finite element modelling of the composite panel CAD model of the panel with four load cases with different material types. The results are used to determine the most capable material stresswise.

Dynamic Finite Element Analysis of a Cylindrical Roller Bearing

2011 ◽  
Vol 143-144 ◽  
pp. 437-442
Author(s):  
Bao Hong Tong ◽  
Yin Liu ◽  
Xiao Qian Sun ◽  
Xin Ming Cheng
Keyword(s):  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Roller Bearing ◽  
Element Analysis ◽  
Dynamic Finite Element ◽  
Dynamic Finite Element Analysis ◽  
Simulation Results ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

A dynamic finite element analysis model for cylindrical roller bearing is developed, and the complex stress distribution and dynamic contacting nature of the bearing are investigated carefully based on ANSYS/LS-DYNA. Numerical simulation results show that the stress would be bigger when the element contacting with the inner or outer ring than at other times, and the biggest stress would appear near the area that roller contacting with the inner ring. Phenomenon of stress concentration on the roller is found to be very obvious during the operating process of the bearing system. The stress distributions of different elements are uneven on the same side surface of roller in its axis direction. Numerical simulation results can give useful references for the design and analysis of rolling bearing.

scholarly journals Experimental Research and Numerical Simulation on Grouting Quality of Shield Tunnel Based on Impact Echo Method

2016 ◽  
Vol 2016 ◽  
pp. 1-10
Author(s):  
Fei Yao ◽  
Guangyu Chen ◽  
Jianhong Su
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Working Conditions ◽  
Acoustic Impedance ◽  
Shield Tunnel ◽  
Test Results ◽  
Impact Echo ◽  
Simulation Results ◽  
The Impact ◽  
Impact Echo Method

To identify shield grouting quality based on impact echo method, an impact echo test of segment-grouting (SG) test piece was carried out to explore effect of acoustic impedance of grouting layers and grouting defects on impact echo law. A finite element numerical simulation on the impact echo process was implemented. Test results and simulation results were compared. Results demonstrated that, under some working conditions, finite element simulation results and test results both agree with theoretical values. The acoustic impedance ratio of SG material influenced the echo characteristics significantly. But thickness frequency could not be detected under some working conditions because the reflected energy is weak. Frequency feature under grouting defects was more complicated than that under no grouting defects.

The effects of shape memory alloys’ tension–compression asymmetryon NiTi endodontic files’ fatigue life

2018 ◽  
Vol 232 (5) ◽  
pp. 437-445 ◽  
Author(s):  
MR Karamooz-Ravari ◽  
R Dehghani
Keyword(s):  
Finite Element ◽  
Shape Memory ◽  
Numerical Models ◽  
Equivalent Stress ◽  
Element Model ◽  
Niti Shape Memory Alloy ◽  
Element Analysis ◽  
Tension And Compression ◽  
Von Mises Equivalent Stress ◽  
Von Mises

Nowadays, NiTi rotary endodontic files are of great importance due to their flexibility which enables the device to cover all the portions of curved canal of tooth. Although this class of files are flexible, intracanal separation might happen during canal preparation due to bending or torsional loadings of the file. Since fabrication and characterization of such devices is challenging, time-consuming, and expensive, it is preferable to predict this failure before fabrication using numerical models. It is demonstrated that NiTi shape memory alloy shows asymmetric material response in tension and compression which can significantly affect the lifetime of the files fabricated from. In this article, the effects of this material asymmetry on the bending response of rotary files are assessed using finite element analysis. To do so, a constitutive model which takes material asymmetry into account is used in combination with the finite element model of a RaCe file. The results show that the material asymmetry can significantly affect the maximum von Mises equivalent stress as well as the force–displacement response of the tip of this file.

Numerical Simulation and Process Research for Cylindrical Drawing

2010 ◽  
Vol 20-23 ◽  
pp. 1405-1408 ◽  
Author(s):  
Wei Hua Kuang ◽  
Qun Liu
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Process Research ◽  
Die Design ◽  
Drawing Process ◽  
3D Finite Element ◽  
Simulation Results ◽  
Distribution Of Stress

Drawing process is an important technology in shaping products. In the paper, the geometric surfaces of tools and sheet were modeled by Pro/E software, and a 3D finite element model of the cylindrical drawing process was developed by DYNAFORM. Numerical simulation results showed the distribution of stress, strain and thickness. FLD showed no material was in crack area and risk crack area. The drawing process could be successfully completed in one stroke. The simulation results were helpful for the die design.

The Impact Analysis of Ground Stability Caused by Exploiting Underground Coal

2011 ◽  
Vol 243-249 ◽  
pp. 3147-3150
Author(s):  
Shu Xian Liu ◽  
Xiao Gang Wei ◽  
Shu Hui Liu ◽  
Li Ping Lv
Keyword(s):  
Numerical Simulation ◽  
Coal Mining ◽  
Impact Analysis ◽  
Shear Failure ◽  
Failure Process ◽  
Wall Rock ◽  
Strong Impact ◽  
Element Analysis ◽  
Deformation And Failure ◽  
The Impact

Disaster caused by exploiting underground coal is due to original mechanical equilibrium of underground rock has been destroyed when underground coal is exploited. And Stress redistribution and stress concentration of wall rock in the goaf happened too. As many complex factors exist such as complex structures of ground, multivariate stope boundary conditions, many stochastic mining factors and so on, it is difficult to evaluate the damage of the geological environment caused the excavation by surrounding underground coal accurately. Besides that, the coexistence of continuous and discontinuous of deformation and failure of wall rock make a strong impact on the ground, and the co-exist of tension, compression and shear failure also pay a great deal contribution to the destroy. Due to the mechanical property and deformation mechanism of goaf are complex , changeable, nonlinear and probabilistic, which changes with in space and time dynamically, it can not be studied analytically by the classical mathematical model and the theory of mechanics computation. Through finite element analysis software ABAQUS, a numerical simulation of the process of underground coal mining have been made. After make a research of the simulation process, it shows the change process of stress environment of wall rock and deformation and failure process of rock mass during the process of coal mining. The numerical simulation of the process can provide theoretical basis and technical support to the protection and reinforcement of laneway the process of coal excavation. Besides that, it also provides a scientific basis and has a great significance to reasonable Excavation and control of mind-out area.

Finite Element Analysis of Resisting Explosive Loading for Mine Escape Capsule

2012 ◽  
Vol 446-449 ◽  
pp. 2206-2209
Author(s):  
Jin Long Wang
Keyword(s):  
Finite Element ◽  
Shock Waves ◽  
Simulation Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Explosive Loading ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Simulation Results ◽  
Three Dimensional Finite Element

Three-dimensional finite element model of the mine escape capsule is established. With the different values of explosion shock waves, simulation analysis of the entry locker is performed by using ABAQUS. The simulation results indicate that the mine escape capsule is safe and available if the surge pressure of shock waves is less than 3.5Mpa.

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