Dynamic factor to live load regulation during structural calculation of bridges at high-speed networks

2017 ◽  
pp. 15-27 ◽  
Author(s):  
Leonid Dyachenko ◽  
Andrey Benyn ◽  
Vladimir Smyrnov
Keyword(s):  
Dynamic Analysis ◽  
High Speed ◽  
Strain State ◽  
Dynamic Factor ◽  
Live Load ◽  
Labor Costs ◽  
Stress Strain ◽  
Stress Strain State ◽  
Dynamic Factors ◽  
High Speed Trains

Objective: Improvement of dynamic analysis method of simple beam spans in the process of high-speed trains impact. Methods: Mathematical modeling with numerical and analytical methods of building mechanics was applied. Results: The parameters of high-speed trains influence on simple beam spans of bridges were analyzed. The method of dynamic factor to live load determination was introduced. The reliability of the method in question was corroborated by the results of numerical simulation of high-speed trains’ movement by beam spans with different speeds. The introduced algorithm of dynamic analysis was based on the connection between maximum acceleration of a beam span in resonance vibration mode and the basic factors of stress-strain state. The method in question makes it possible to determine both maximum and bottom values of main loading in a construction, which determines the possibility of endurance tests. It was noted that dynamic additions for the components of stress-strain state (bending moments, shear force, vertical deflections) were different. The fact in question determines the necessity of differential approach application to identify dynamic factors in the process of calculation testing on the first and the second groups of limit states. Practical importance: The method of dynamic factors’ determination presented in the study makes it possible to perform dynamic analysis and determine the main loading in simple beam spans without application of numerical modeling and direct analytical analysis, which considerably reduces labor costs on engineering.

scholarly journals Rating of Dynamic Coefficient for Simple Beam Bridge Design on High-Speed Railways

2018 ◽  
Vol 14 (1) ◽  
pp. 37-43 ◽  
Author(s):  
Leonid Diachenko ◽  
Andrey Benin ◽  
Vladimir Smirnov ◽  
Anastasia Diachenko
Keyword(s):  
Numerical Simulation ◽  
High Speed ◽  
Strain State ◽  
Practical Importance ◽  
Stress Strain ◽  
Dynamic Coefficients ◽  
Stress Strain State ◽  
Dynamic Computation ◽  
High Speed Trains ◽  
The Impact

AbstractThe aim of the work is to improve the methodology for the dynamic computation of simple beam spans during the impact of high-speed trains.Mathematical simulation utilizing numerical and analytical methods of structural mechanics is used in the research.The article analyses parameters of the effect of high-speed trains on simple beam spanning bridge structures and suggests a technique of determining of the dynamic index to the live load. Reliability of the proposed methodology is confirmed by results of numerical simulation of high-speed train passage over spans with different speeds. The proposed algorithm of dynamic computation is based on a connection between maximum acceleration of the span in the resonance mode of vibrations and the main factors of stress-strain state. The methodology allows determining maximum and also minimum values of the main efforts in the construction that makes possible to perform endurance tests. It is noted that dynamic additions for the components of the stress-strain state (bending moments, transverse force and vertical deflections) are different. This condition determines the necessity for differentiated approach to evaluation of dynamic coefficients performing design verification of I and II groups of limiting state. The practical importance: the methodology of determining the dynamic coefficients allows making dynamic calculation and determining the main efforts in split beam spans without numerical simulation and direct dynamic analysis that significantly reduces the labour costs for design.

scholarly journals Influence of the concrete strength and the type of supports on the stress-strain state of a hyperbolic paraboloid shell footbridge structure

2021 ◽  
Vol 17 (4) ◽  
pp. 379-390
Author(s):  
David Cajamarca-Zuniga ◽  
Sebastian Luna
Keyword(s):  
Thin Shell ◽  
Strain State ◽  
Concrete Strength ◽  
Design Parameters ◽  
Live Load ◽  
Structural Behaviour ◽  
Stress Strain ◽  
Hyperbolic Paraboloid ◽  
Element Analysis ◽  
Stress Strain State

Relevance. This work is the first in a series of publications on the selection of a suitable analytical surface for implementation as a self-supporting structure for a thin shell footbridge. The study on the influence of concrete strength, live load position and support types on the stress-strain state of a hyperbolic paraboloid (hypar) shell is presented. Objective - to define the initial design parameters such as the appropriate concrete strength and the support type that generates the best structural behaviour to perform the subsequent structural design of a thin shell footbridge. Methods. The static finite element analysis was performed for 4 compressive strengths of concrete (28, 40, 80, 120 MPa) which correspond normal, high and ultra-high resistance concrete, 5 different live load arrangements and 3 different support conditions. Results. The shell model with pinned (two-hinged) supports shows the same vertical displacements as the model with fixed supports (hingeless). For the studied shell thickness, in terms of stress behaviour, the model with pinned ends is more efficient. The combination of two-hinged supports with 80 MPa concrete strength shows a better structural performance.

scholarly journals Dynamics of Welded Rails Gap and Hardness of Rail Base

2020 ◽  
Vol 25 (1) ◽  
pp. 236-242
Author(s):  
T.I. Zaitseva ◽  
I.V. Blinova ◽  
A.M. Uzdin
Keyword(s):  
Elastic Foundation ◽  
Traffic Safety ◽  
Thermal Deformation ◽  
Strain State ◽  
Dynamic Factor ◽  
Stress Strain ◽  
Stress Strain State ◽  
Continuous Welded Rail ◽  
Negative Effect ◽  
Rigid Insert

AbstractThe problem of gap estimation for a break of a continuous welded rail is studied. The track is represented as a semi-infinite rod on elastic-based damping. Static and dynamic solutions are obtained. It is shown that during the rail break, the dynamic factor does not exceed 1.5. We derive equations for thermal deformation of the welded rail of jointless track on an elastic foundation in the presence of the insert into the base with another characteristic stiffness. It is shown that the presence of the insertion of up to 20% of the length of the rail, with both large and small stiffness, has a little effect on the stress-strain state (SSS) of the track. The presence of a rigid insert may increase the clearance of an accidental break of the rail, which has a negative effect on traffic safety.

The Quality Improvement in Manufacturing “Screw”-Parts Using the DEFORM-3D Software

2016 ◽  
Vol 684 ◽  
pp. 468-472 ◽  
Author(s):  
Sergey Zvonov ◽  
Aleksey Shlyapugin
Keyword(s):  
Aluminum Alloy ◽  
Quality Improvement ◽  
High Speed ◽  
Strain State ◽  
High Efficiency ◽  
Metal Flow ◽  
Stress Strain ◽  
Stress Strain State ◽  
3D Software ◽  
Deform 3D

The check of developed inventory for high-speed stamping "Screw"-part forging fabricated from aluminum alloy by using DEFORM is performed. The high efficiency of the program is shown. The characteristic of metal flow and stress-strain state during the processing is opened.

Flexible bar buckling under short-time and long-term compressions

2020 ◽  
Vol 17 (1) ◽  
pp. 199-210
Author(s):  
Anton Egorov ◽  
Vitaly Egorov
Keyword(s):  
Dynamic Analysis ◽  
Mechanical Behaviour ◽  
Strain State ◽  
Stress Strain ◽  
Content Type ◽  
Stress Strain State ◽  
Bar Buckling ◽  
Comparison Of The Results ◽  
Short Time

PurposeThe purpose of this paper is to expand possibilities of stability computing method when performing a dynamic analysis of bar- or rod-shaped elements for actual structures.Design/methodology/approachThe methodology is based on the changes of stress–strain state of the bar-shaped elements at the moment of buckling. The proposed method is based on three assumptions. Firstly, the spatial stress–strain state is determined in the bar. Secondly, technological deviations inherent in real structures are introduced into the bar. Thirdly, mechanical behaviour of the bar is investigated in the mode of real time, which makes it possible to take into account wave deformation processes in the bar. To implement the suggested method of analysis, LS-DYNA package was selected in a dynamic formulation using solid finite elements.FindingsValidity of the proposed method is shown by an example of dynamic stability analysis of a steel flat thin bar with two types of loads: short-time and long-term axial compressions. Comparison of the results showed different nature of the mechanical behaviour of the bar: wave processes are observed under short-time loading, and continuous monotone ones are stated under long-term loads.Practical implicationsResearch results are applicable in the rocket and space industry.Originality/valueA new computer-based methodology for dynamic analysis of heterogeneous elastic-plastic bar-, rod-shaped structures under shock axial compressive loads is proposed.

scholarly journals Analysis of the stress-strain state of the "High-speed shaft" part

2021 ◽  
Author(s):  
YA.G. Karyachkin ◽  
D.S. Kenyajkin ◽  
S.A. Efanov
Keyword(s):  
High Speed ◽  
Strain State ◽  
Stress Strain ◽  
Stress Strain State

scholarly journals Discussing the effect of the wheelset equivalent conicity on the stress-strain state of the rails

2021 ◽  
Vol 2021 (2) ◽  
pp. 261-272
Author(s):  
Lyudmila S. BLAZHKO ◽  
◽  
Artem A. KISELEV ◽  
Igor P. KISELEV ◽  
Andrey V. ROMANOV ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Field Experiment ◽  
High Speed ◽  
Strain State ◽  
Practical Importance ◽  
Experimental Studies ◽  
Resistance Force ◽  
Stress Strain ◽  
Stress Strain State ◽  
Equivalent Conicity

Objective: To assess the effect of the wheelset equivalent conicity on the stress-strain state of the rails. Methods: Authors used numerical integration methods for systems of nonlinear differential equations of motion in the Universal Mechanism software package. Experimental studies were carried out on the St. Petersburg – Moscow high-speed line using a multichannel strain-gauge station. Methods of mathematical statistics have been used to process the results of numerical simulation and field experiment. Results: The stresses and strains in the wheel-rail contact area and their dependence on the wheelset equivalent conicity have been determined. According to numerical simulation and field experiment, the convergence was within 15 %. Practical importance: The need for updating the standards for the maintenance of a rail track on high-speed lines has been revealed. Allowing for the wheelset equivalent conicity decreases the risk of intense hunting oscillation, which would reduce the dynamic wheel–rail effect. Mobile treatment of rails on the way makes it possible to extend the safe operation time and reduce the rolling stock motion resistance force of the track.

scholarly journals Numerical simulation of stress-strain state of oblique sections of reinforced concrete structures subjected to compression and bending on yielding supports under short-term dynamic load

2019 ◽  
Vol 221 ◽  
pp. 01033
Author(s):  
Nikita Mescheulov ◽  
Oleg Kumpyak
Keyword(s):  
Reinforced Concrete ◽  
Dynamic Analysis ◽  
Strain State ◽  
Blast Resistance ◽  
Dynamic Amplification Factor ◽  
Stress Strain ◽  
Stress Strain State ◽  
Equivalent Static Load ◽  
Dynamic Amplification ◽  
Concrete Elements

This research is aimed at studying the method for improving blast resistance of buildings and structures by using yielding supports. The paper reports the data on dynamic analysis of reinforced concrete elements subjected to compression and bending on yielding supports under the condition of elasto-plastic stress-strain state performed in ANSYS software package. Algorithms and techniques for dynamic amplification factor calculation for reinforced concrete elements subjected to compression and bending are presented. The paper provides load diagrams of dynamic amplification factors with the account of yielding capacity of supports for subsequent dynamic analysis of structures for equivalent static load.

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