Parametric Instability of Tapered Beams by Finite Element Method

1982 ◽  
Vol 24 (4) ◽  
pp. 205-208 ◽  
Author(s):  
P. K. Datta ◽  
S. Chakraborty
Keyword(s):  
Finite Element ◽  
Dynamic Load ◽  
Parametric Instability ◽  
Mathieu Equation ◽  
Stability Diagram ◽  
Load Factor ◽  
Element Analysis ◽  
Load Factors ◽  
Principal Region ◽  
Dynamic Load Factor

The dynamic stability behaviour of a tapered beam has been studied using a finite element analysis. The instability zones of the parametric stability diagram have been discussed for the entire ranges of static and dynamic load factors. It has been observed that at high values of static load and beyond a particular value of the dynamic load factor, the periodic solution of the Mathieu equation does not exist in the principal region. This leads to unstable behaviour due to large displacement of the beam due to increasing values of static and dynamic load factors.

The Effects of Solid Viscosities to Dynamic Load Factors of the Ring and the Hollow Sphere Subjected to Impulsive Loads

1968 ◽  
Vol 72 (695) ◽  
pp. 971-976 ◽  
Author(s):  
Shin-Ichi Suzuki
Keyword(s):  
Hollow Sphere ◽  
Dynamic Load ◽  
Higher Dimensions ◽  
Point Of View ◽  
Load Factor ◽  
Vacuum Vessel ◽  
Load Factors ◽  
Impulsive Loads ◽  
Damped Oscillation ◽  
Dynamic Load Factor

Although it has been said that dynamic load factor is equal to 2, it became evident by the author's researches that this value is influenced by the dimensions of members and loading conditions and is very different from 2. However, the solid viscosities are neglected in all these researches. Previously, the author obtained the coefficients of viscosities from the experimental results of damped oscillation of a cantilever beam in a vacuum vessel and investigated the relationships between dynamic load factors and solid viscosities on the beam and the rod subjected to transverse or longitudinal impulsive loads. From these results, it was found that the effects of solid viscosities to dynamic load factors cannot be neglected. To find out whether the same fact can be obtained for the higher dimensions or not, the ring and the hollow sphere subjected to uniformly distributed impulsive loads along the inner and outer edges are analysed. Since σθ, the direct stress to the circumferential direction, is the most important from the engineering point of view, the relationships between solid viscosities and dynamic load factors of σθ are investigated.

scholarly journals Numerical and experimental study of the dynamic factor of the dynamic load on the urban railway

2020 ◽  
Vol 29 (1) ◽  
pp. 195-202
Author(s):  
Tran Anh Dung ◽  
Mai Van Tham ◽  
Do Xuan Quy ◽  
Tran The Truyen ◽  
Pham Van Ky ◽  
...  
Keyword(s):  
Experimental Study ◽  
Dynamic Load ◽  
Dynamic Measurement ◽  
Experimental Results ◽  
Load Factor ◽  
Dynamic Factor ◽  
Experimental Measurements ◽  
Train Speed ◽  
Dynamic Load Factor

AbstractThis paper presents simulation calculations and experimental measurements to determine the dynamic load factor (DLF) of train on the urban railway in Vietnam. Simulation calculations are performed by SIMPACK software. Dynamic measurement experiments were conducted on Cat Linh – Ha Dong line. The simulation and experimental results provide the DLF values with the largest difference of 2.46% when the train speed varies from 0 km/h to 80 km/h

Finite Element Analysis of the ESTELA M1 Airplane Firewall (Representative Specimen)

2011 ◽  
Author(s):  
V. Ramirez-Elias ◽  
E. Ledesma-Orozco ◽  
H. Hernandez-Moreno
Keyword(s):  
Finite Element ◽  
Federal Aviation Administration ◽  
Element Model ◽  
Maximum Load ◽  
Load Factor ◽  
Representative Specimen ◽  
Maximum Displacement ◽  
Element Analysis ◽  
Element Simulation ◽  
The Relationship

This paper shows the finite element simulation of a representative specimen from the firewall section in the AEROMARMI ESTELA M1 aircraft. This specimen is manufactured in glass and carbon / epoxy laminates. The specimen is subjected to a load which direction and magnitude are determined by a previous dynamic loads study [10], taking into account the maximum load factor allowed by the FAA (Federal Aviation Administration) for utilitarian aircrafts [11]. A representative specimen is manufactured with the same features of the firewall. Meanwhile a fix is built in order to introduce the load directions on the representative specimen. The relationship between load and displacement is plotted for this representative specimen, whence the maximum displacement at the specific load is obtained, afterwards it is compared with the finite element model, which is modified in its laminate thicknesses in order to decrease the deviation error; subsequently this features could be applied to perform the whole firewall analysis in a future model [10].

Determination of wheelchair dynamic load data for use with finite element analysis

1996 ◽  
Vol 4 (3) ◽  
pp. 161-170 ◽  
Author(s):  
D.P. VanSickle ◽  
R.A. Cooper ◽  
R.N. Robertson ◽  
M.L. Boninger
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Dynamic Load ◽  
Element Analysis

Capacity Analysis of PE Pipeline With Non-Planar Defect

2013 ◽  
Author(s):  
Weijie Jiang ◽  
Jianping Zhao ◽  
Dingyue Chen
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Constitutive Model ◽  
Mechanical Performance ◽  
Orthogonal Design ◽  
Bending Moment ◽  
Limit Load ◽  
Capacity Analysis ◽  
Element Analysis ◽  
Load Factors

A tensile test of buried PE pipe is designed to test the mechanical performance. Then the constitutive model for the PE pipe can be established. The limit load of the PE pipe with local thinning defect can be studied with the method of combining the orthogonal design of experiment and finite element analysis. Then the factors of local thinning defect pipe limit load factors can be analyzed. The results show that the depth of the defect has a great effect on the limit load (internal pressure and bending moment) of PE pipe. The effects that the axial length of the defect and the circumferential length of the defect have on the limit load are not significant.

scholarly journals Evaluation of Dynamic Load Factors for a High-Speed Railway Truss Arch Bridge

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Ding Youliang ◽  
Wang Gaoxin
Keyword(s):  
Finite Element ◽  
Dynamic Load ◽  
High Speed ◽  
Field Monitoring ◽  
Generalized Extreme Value Distribution ◽  
Monitoring Data ◽  
Load Factor ◽  
High Speed Railway ◽  
Arch Bridge ◽  
The Impact

Studies on dynamic impact of high-speed trains on long-span bridges are important for the design and evaluation of high-speed railway bridges. The use of the dynamic load factor (DLF) to account for the impact effect has been widely accepted in bridge engineering. Although the field monitoring studies are the most dependable way to study the actual DLF of the bridge, according to previous studies there are few field monitoring data on high-speed railway truss arch bridges. This paper presents an evaluation of DLF based on field monitoring and finite element simulation of Nanjing DaShengGuan Bridge, which is a high-speed railway truss arch bridge with the longest span throughout the world. The DLFs in different members of steel truss arch are measured using monitoring data and simulated using finite element model, respectively. The effects of lane position, number of train carriages, and speed of trains on DLF are further investigated. By using the accumulative probability function of the Generalized Extreme Value Distribution, the probability distribution model of DLF is proposed, based on which the standard value of DLF within 50-year return period is evaluated and compared with different bridge design codes.

scholarly journals Dynamic Behavior of Steel and Composite Ferry Subjected to Transverse Eccentric Moving Load Using Finite Element Analysis

2020 ◽  
Vol 10 (15) ◽  
pp. 5367 ◽  
Author(s):  
Mohamed N. Lotfy ◽  
Yasser A. Khalifa ◽  
Abdelrahim K. Dessouki ◽  
Elsayed Fathallah
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Load Capacity ◽  
Moving Load ◽  
Load Factor ◽  
Principal Stresses ◽  
Element Analysis ◽  
Software Analysis ◽  
Analysis System ◽  
Von Mises

The most important problems confronted by designers of floating structures are minimizing weight and increasing payload to get proper resistance to the applied loads. In the present study, the structural performance of a ferry is analyzed using both metallic and composite materials as a result of the dynamic load of the Military Load Capacity (MLC) 70 (tank load). The model is composed of sixteen floating pontoons. Finite element simulation and dynamic analysis were performed using ANSYS software (analysis system software), considering a moving MLC70 (tank load). Both concentric and eccentric cases of loading are considered. Draft, deformation, and stresses are obtained and investigated. For the steel ferry, the von-Mises stresses are investigated, while for the composite ferry, the maximum principal stresses are investigated. Furthermore, buckling analysis is performed on the composite ferry and the buckling load factor is determined. The results of the dynamic analysis illustrated that the transverse eccentricity of the moving tank MLC70 must not exceed 0.5 m for a steel ferry while it may reach up to 1.5 m for the composite ferry. This research can also be a useful tool in the design of floating composite and steel ferries.

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