Application of Exact Element-Method on Calculation of Form-Finding and Unstressed Length of Cable

2013 ◽  
Vol 405-408 ◽  
pp. 1699-1708
Author(s):  
Zhou Li ◽  
Yuan Cheng Wei ◽  
Rong Hui Wang ◽  
Jia Lun Li ◽  
Peng Zhang
Keyword(s):  
Finite Element ◽  
Solution Process ◽  
Suspension Bridge ◽  
Equilibrium Relation ◽  
Form Finding ◽  
Finite Element Software ◽  
Main Cable ◽  
Computational Procedures ◽  
Shape Curve ◽  
Element Method

The problem of form-finding for the suspended cable is actually the problem of determining all key points coordinates on main cable, which are by equilibrium relation on the horizontal force, main cable sagitta and lifting point force under the precondition of determining the endpoints boundary conditions of cable segment. According from the static equilibrium relationship of cable element, based on the analysis of its analytical solution process, in this paper, the cable elements are divided into two types in accordance withthe vertical distribution load along the arc length and along the string length , the corresponding shape curve of cable element is the parabola and the catenary, and with parabolic results as its initial value for the iteration of nonlinear solution, then cable element eventually converge for the catenary. And based on the exact coordinates results ,the calculation method of the length without stress is presented,and compiled corresponding computational procedures. By comparing the results of form-finding and the cable-length in non-stress according to program compiled and the results from the finite element software and the measured value of Aizhai suspension bridge, compared with the nonlinear finite element method,it confirmed the method requireing smaller dividing element density, the convergence speed is quicker and the results can ensure the precision.

A Coupled SBFEM-FEM Approach for Evaluating Stress Intensity Factors

2013 ◽  
Vol 353-356 ◽  
pp. 3369-3377 ◽  
Author(s):  
Ming Guang Shi ◽  
Chong Ming Song ◽  
Hong Zhong ◽  
Yan Jie Xu ◽  
Chu Han Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Complex Geometry ◽  
Stress Singularity ◽  
Intensity Factors ◽  
Finite Element Software ◽  
Scaled Boundary Finite Element ◽  
Element Method

A coupled method between the Scaled Boundary Finite Element Method (SBFEM) and Finite Element Method (FEM) for evaluating the Stress Intensity Factors (SIFs) is presented and achieved on the platform of the commercial finite element software ABAQUS by using Python as the programming language. Automatic transformation of the finite elements around a singular point to a scaled boundary finite element subdomain is realized. This method combines the high accuracy of the SBFEM in computing the SIFs with the ability to handle material nonlinearity as well as powerful mesh generation and post processing ability of commercial FEM software. The validity and accuracy of the method is verified by analysis of several benchmark problems. The coupled algorithm shows a good converging performance, and with minimum additional treatment can be able to handle more problems that cannot be solved by either SBFEM or FEM itself. For fracture problems, it proposes an efficient way to represent stress singularity for problems with complex geometry, loading condition or certain nonlinearity.

Teaching the Finite Element Method As a Design Tool for Mechanical Engineering

1993 ◽  
Author(s):  
T. R. Grimm
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Solution Process ◽  
Thinking Skills ◽  
Design Tool ◽  
Basic Solution ◽  
The Finite Element Method ◽  
The Matrix ◽  
Analysis Of Results ◽  
Element Method

Abstract The importance of the finite element method as an engineering tool for design and analysis is emphasized in a senior level elective course taught at Michigan Technological University. The course emphasizes hands-on experience with computers and the pre- and post-analysis of results to establish confidence in solutions obtained. The students learn by using the finite element method to “solve” several design projects, rather than by being told about the method without significant actual experience. They also learn about the basis of the method, including formation of the matrix equations required and the numerical methods used in their solution. Intelligent use of the method requires that engineers understand both the mechanics of how to apply the method, i.e modeling requirements, and the limitations imposed by the basic solution process. The course provides the students with important experience in using the powerful finite element method as a design tool. It requires a strong background of fundamentals and stimulates the problem solving thinking skills so essential to industry.

CALCULATION OF DISPERSION CURVES FOR ARBITRARY WAVEGUIDES USING FINITE ELEMENT METHOD

2014 ◽  
Vol 06 (05) ◽  
pp. 1450059 ◽  
Author(s):  
KAIGE ZHU ◽  
DAINING FANG
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Guided Waves ◽  
Dispersion Curves ◽  
Guided Wave ◽  
Sandwich Plates ◽  
Multilayered Structures ◽  
Finite Element Software ◽  
Honeycomb Sandwich ◽  
Element Method

Dispersion curves for waveguide structures are an important prerequisite for the implementation of guided wave-based nondestructive evaluation (NDE) approach. Although many methods exist, each method is only applicable to a certain type of structures, and also requires complex programming. A Bloch theorem-based finite element method (FEM) is proposed to obtain dispersion curves for arbitrary waveguides using commercial finite element software in this paper Dispersion curves can be obtained for a variety of structures, such as homogeneous plates, multilayered structures, finite cross section rods and honeycomb sandwiches. The propagation of guided waves in honeycomb sandwich plates and beams are discussed in detail. Then, dispersion curves for honeycomb sandwich beams are verified by experiments.

scholarly journals Optimization Method of the Car Seat Rail Abnormal Noise Problem Based on the Finite Element Method

2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Huijie Yu ◽  
Xinkan Zhang ◽  
Chen Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Natural Frequencies ◽  
Joint Probability ◽  
Element Model ◽  
Joint Probability Distribution ◽  
Natural Frequencies And Modes ◽  
Car Seat ◽  
Finite Element Software ◽  
Element Method

The finite element model of the seat rail is established with a spring-damping element to simulate the ball in the rail joint part. The stiffness and damping parameters of the joint part are determined by the combination of finite element method and experiment. Firstly, the natural frequencies and modes of the guide rail are obtained by modal experiment. The stiffness of the spring-damping element is optimized in the finite element software to make the natural frequencies and modes of the system consistent with the experimental ones. Secondly, the dynamic response curve of the key nodes is obtained through sweeping experiment, and the damping of the spring-damping element is optimized in the finite element software to make the nodal response of the system output consistent with the experiment. Then, the gap of the joint part of the car seat rail is studied considering the factors of load and structure randomness. The influence factors of the gap are selected by Hammersley experimental design method. The results show that the gap is normally distributed, and therefore the confidence interval of the gap is obtained. Finally, the joint probability distribution of the gap is obtained under the condition that the load and the structure are all random, which provides the theoretical guidance for determining the reasonable gap of the joint.

A Iterative Computation Method for Main Cable Shape Calculation of Self-Anchored Suspension Bridge

2013 ◽  
Vol 477-478 ◽  
pp. 666-670
Author(s):  
Xu Ming Song
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Calculation ◽  
Suspension Bridge ◽  
Internal Force ◽  
Computation Method ◽  
The Real ◽  
Iterative Computation ◽  
Calculating Method ◽  
Main Cable

Both finite element method and cable numerical calculation have their limitations in calculation of main cable shape for self-anchored suspension bridge. This paper combined the characteristics of the two methods, and worked out the cable shape and internal force of self-anchored suspension bridge though iterative computation. Sanchaji Bridge, a self-anchored suspension bridge in Changsha city, its main cable shape was calculated by this method. Calculating results show that the real shape of main cable fit the results well and we should carefully calculate the length of girder compression which influences the unstressed length of main cable and the position of hangers. The calculating method adopted in Sanchaji Bridge offered a reference for design and construction for similar bridges.

Numerical Simulation of Ultimate of Slings for Three-Tower and Four-Span Suspension Bridge under Tanker Fire

2013 ◽  
Vol 361-363 ◽  
pp. 1187-1193
Author(s):  
Mu Yu Liu ◽  
Wei Tian ◽  
Ying Wang ◽  
Wu Jing
Keyword(s):  
Finite Element ◽  
Failure Time ◽  
Three Dimensional ◽  
Fire Risk ◽  
Suspension Bridge ◽  
Element Model ◽  
Prevention Measures ◽  
Heating Curve ◽  
Finite Element Software ◽  
Three Dimensional Finite Element

Three-dimensional finite element model of Yingwuzhou Yangtze river bridge was established by using the finite element software ANSYS. Since the characteristics of bridge fire differed much from that of buildings, Heating curve HCincwas selected as heating curve caused by tanker fire. Heat loading was imposed on the middle of main span where the tanker fire had taken place of three-tower and four-span suspension bridge . The temperature field and stress, modulus of elasticity, strength of sling changing with time caused by tanker burning in midspan were systematically investigated to obtain the failure time of the sling. The calculation also compared the above results of HCinccurve with that of ISO834 curve. This research can provide some references to fire risk prevention measures of bridge during its service life.

Object-Oriented Computer-Aided Analysis for Construction Control of Anchored Suspension Bridge

2014 ◽  
Vol 543-547 ◽  
pp. 3977-3981
Author(s):  
Jian Yuan Sun ◽  
Cheng Zhang Yin ◽  
Zeng Bao Ma
Keyword(s):  
Safety Margin ◽  
Object Oriented ◽  
Suspension Bridge ◽  
High Accuracy ◽  
Object Oriented Programming ◽  
Suspension Bridges ◽  
Construction Control ◽  
Control Analysis ◽  
Finite Element Software ◽  
Main Cable

With the increase of the span of suspension bridge, the weight of the main cable increases, and the safety margin becomes smaller. Thus high accuracy is necessary for the construction control analysis of suspension bridges. The traditional finite element software cannot meet the accuracy requirement because of temperature, cable saddle and other factors, which influence the construction control. Based on the modified segmental catenary method, this paper has come up with a fine analysis method for the construction control of suspension bridges. And a software program called ZambisSC has been developed using object-oriented programming language combined with a number of the latest software development technologies. Compared with the monitoring results of Nancha suspension bridge in Guangzhou, China, it shows that ZambisSC can predict the main cable shape with high accuracy.

Optimization Dressing Method of Amplitude Transformer Based on Finite Element

2013 ◽  
Vol 278-280 ◽  
pp. 315-318
Author(s):  
Ming Li Zhao ◽  
Bo Zhao ◽  
Yu Qing Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Resonant Frequency ◽  
Structural Parameters ◽  
Low Cost ◽  
Dressing Method ◽  
Finite Element Software ◽  
System Vibration ◽  
Vibration Performance ◽  
Element Method

The node position of amplitude transformer was determined by the finite element method, and the flange was designed at the nod position for conveniently installation. By the finite element software, the amplitude transformer with flange was optimized and dressed, and its structural parameters were determined. During the actual manufacturing process, it was used impedance analyzer to test its vibration performance, the testing results show that this system vibration performance is good, its resonant frequency is 34.771kHz, anti-resonant frequency is 35.008kHz. The above-mentioned results are very much coincided with the system natural frequency of 34.893kHz which is drew by finite element method. Compared to the traditional dressing this method has many advantages such as convenience, green, environmental protection, low cost and others.

A Discontinuous Finite Element Method for Non-Fourier Heat Conduction Problems

2003 ◽  
Author(s):  
X. Ai ◽  
B. Q. Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Heat Conduction ◽  
Numerical Solutions ◽  
Mathematical Formulation ◽  
Discontinuous Galerkin Finite Element ◽  
Discontinuous Finite Element ◽  
Fourier Heat Conduction ◽  
Computational Procedures ◽  
Element Method

A discontinuous Galerkin finite element method is presented for the solution of non-Fourier heat conduction problems that arise from the thermal processing of thin films using the ultra-short pulsed lasers. Mathematical formulation is described in detail and computational procedures are given. Numerical example are given and compare with available solutions where available. The numerical solutions exhibit strong wave behavior and reflection and interactions of thermal waves at the boundaries in multi-dimensions.

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