scholarly journals Determination of ASI and THIV parameters based on the results of experimental and numerical research in relation to EU standards

2021 ◽  
Vol 338 ◽  
pp. 01025
Author(s):  
Michał Stopel
Keyword(s):  
Experimental Tests ◽  
Severity Index ◽  
Point Of View ◽  
The Finite Element Method ◽  
Safety Level ◽  
The Road ◽  
Road Sign ◽  
Numerical Research ◽  
Python Programming

Determining the values of ASI (Acceleration Severity Index) and THIV (Theoretical Head Impact Velocity) parameters during tests allows you to assign an appropriate class for a given type of object to determine the safety level and to give the CE marking. The paper presents the methodology for determining these parameters based on the EN 1317-1 and EN 12767 standards. The paper also presents a tool created with the use of the Python programming language, which, based on the results of experimental tests or the results of numerical calculations, allows to determine the ASI and THIV values. The values of key parameters from the point of view of normative tests were calculated based on the results of experimental tests of the road sign supporting mast and numerical analysis carried out for the same case using the Finite Element Method and LS-Dyna software, following the EN 12767 standard.

Repair programs development taking into account the presence of high-risk defects on bridges

2021 ◽  
Vol 2021 (23) ◽  
pp. 158-166
Author(s):  
Larysa Bodnar ◽  
◽  
Serhii Stepanov ◽  
Serhii Zavhorodniy ◽  
Vitalii Yastrubinetskyi ◽  
...  
Keyword(s):  
High Risk ◽  
Management System ◽  
Point Of View ◽  
Bridge Management ◽  
Bridge Management System ◽  
Term Operation ◽  
The Road ◽  
Cost Calculations ◽  
Cost Determination

Introduction. In recent years in Ukraine, the weight and traffic volume of vehicles on the roads have increased significantly. Most of the bridges that are operating on these roads were built according to norms, the design loadings of which are not corresponding to the modern loadings on transport facilities.Problem Statement. The issue of bridges operation with defects of the structure in the condition of limited funding of the road industry become particularly relevant at the present stage, as the age of bridges is constantly increasing, and the resource of their elements is being expiring.Due to limited funding, the economic and time components of the designed models have a significant impact on the quality of performed calculations and the determination of the optimal strategy for performing of repairing work in specified conditions. The choice of planned works is determined during repairing plans development, both for evaluation of the current state of bridges and for determination of predicted bridge repairing terms.Purpose. the purpose of the work is the development of further optimization of the mode of repairs plan development to eliminate existing defects of bridges.Materials and methods. During the determination of repairs cost in the Analytical Expert Bridge Management System (AESUM), the average norms of the work volume were used. This method was limited by the fact that cost calculations were constant and did not consider actual defects of the bridges. The experience of the constructed bridges operation over 40–50 years revealed a significant number of various defects of structure, mainly of spans and piers. The causes of defects are long-term operation without proper maintenance, as well as a number of shortcomings during the design and construction of bridges. In order to further mode optimization of repair plans development, the existing defects on the bridges were studied from the point of view of their impact on the further destruction of certain elements of the bridge, or the facility as a whole, on the acceleration of this process. Such defects have been identified as high risk defects.Results. Scientists of «DerzhdorNDI» SE have developed and applied the technique of repair cost determination by formation of works complex to eliminate existing defects at the inspected facilities. A module for bridge repair planning has been developed considering the need for priority elimination of high risk defects.Conclusions. The technique of repairs cost determination was developed, as well as the module for bridge repair planning considering the need for priority elimination of high risk defects.Keywords: highway bridge, Analytical Expert Bridge Management System (AESUM), repairs cost determination, defect on bridges.

scholarly journals Two-dimensional Analysis of Cracks Propagation in Structures of Concrete

2013 ◽  
Vol 3 (3) ◽  
pp. 429-432
Author(s):  
D. Benarbia ◽  
M. Benguediab ◽  
S. Benguediab
Keyword(s):  
Point Of View ◽  
Two Dimensional ◽  
The Finite Element Method ◽  
Fracture Criteria ◽  
Development Processes ◽  
Mechanical Approach ◽  
Indirect Tensile ◽  
Cracks Propagation ◽  
Phenomenological Point

In this article we present a numerical simulation that allows describing and studying the damage of concrete works subjected to various stress types. In this study, the propagation of cracks in the concrete is analyzed as of their appearance, which requires having a thorough knowledge of the mechanical behavior of the material. The mechanical approach which leads to better understanding of fracture phenomena and can give satisfactory results, is that of the elastic linear mechanics of failure. The interest in this study is focused in the development processes of the cracks from a phenomenological point of view. The analysis is carried out by using fracture criteria while being based on the determination of the critical stress intensity factors, for each case of the several elaborate tests of indirect tensile per bending and Brazilian Disc. The analysis is carried out in a two-dimensional medium by the finite element method by using the ABAQUS software. The results obtained are compared with experimental data obtained analytically from other authors.

scholarly journals Neural networks applications for environmental safety assessment of roads in Ukraine

2014 ◽  
Vol 13 (1) ◽  
pp. 339-347
Author(s):  
Vitalii Naumov ◽  
Natalia Vnukova ◽  
Ganna Zhelnovach
Keyword(s):  
Neural Networks ◽  
Numerical Evaluation ◽  
Safety Assessment ◽  
Environmental Safety ◽  
Fuzzy Information ◽  
Safety Level ◽  
The Road ◽  
On The Road

The analysis of problems and of approaches for ensuring the environmental safety of roads in Ukraine has been performed. The proposed mathematical model on the basis of neural networks allows numerical evaluation of quality of road area in the conditions of incomplete and fuzzy information. The proposed approach allows the determination of roads’ environmental safety level, the indica­tion of necessity for arrangement of environmental monitoring stations, and allows the development of a number of activities for environmental protection on the road sections as well.

scholarly journals THE IMPORTANCE OF THE DETERMINATION OF A JUDICIAL AUTOMOTIVE EQUIPMENT EXAMINATION FROM THE STANDPOINT OF PROCEDURAL CONTRADICTIONS AND THE PRACTICAL RESULT APPLICATION EFFICIENCY

2020 ◽  
Vol 10 ◽  
pp. 17-20
Author(s):  
Evgeniy A. Tarasov ◽  
Keyword(s):  
Point Of View ◽  
Technical Expertise ◽  
Road Accidents ◽  
Practical Result ◽  
Automotive Engineering ◽  
The Road ◽  
Technical Examination ◽  
Special Knowledge

From the point of view of tasks and methodology judicial auto technical examination is considered as a means of obtaining reasonable information for objective consideration of circumstances of road accidents and offenses. The purpose of auto technical expertise as a variety or kind of engineering and transport expertise is to establish all the circumstances associated with an accident or a crime in which the car played the role of object, means, evidence, carrier traces. The criteria allowing to classify a specialist to the category of experts with special knowledge in the field of automotive engineering are presented. The types of forensic auto technical expertise are given. It is said that it is part of the competence of the expert-automotive. The competence of the automotive expert allows to conduct research and give conclusions on specific issues related to vehicles and the road situation in its dynamics, the consequences of accidents. The purpose of the article is to draw the attention of interested persons and organizations to the need to accurately determine the forensic automotive expertise and expert-automotive technician to eliminate a number of issues of a procedural and technical nature.

scholarly journals Numerical Research of Fracture Toughness of Aged Ferritic-Martensitic Steel

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1686
Author(s):  
Remigijus Janulionis ◽  
Gintautas Dundulis ◽  
Albertas Grybėnas
Keyword(s):  
Fracture Toughness ◽  
Numerical Method ◽  
Experimental Tests ◽  
Thermal Ageing ◽  
Experimental Conditions ◽  
Finite Element Software ◽  
Numerical Research ◽  
Determination Methods ◽  
Good Coincidence

Generally, material properties such as the modulus of elasticity, yield strength or fracture toughness are determined by conducting an experiment. Sometimes experimental determination cannot be done due to specific experimental conditions, lack of testing material and so on. Also, experiments are time consuming and costly. Therefore, there arises the need for alternative determination methods. A numerical method for the fracture toughness determination of steel P91 is suggested in this paper. For this purpose, the universal finite element software ABAQUS was used. The numerical simulation of the C(T) specimen tension test was carried out using non-linear simulation for a conditional load PQ determination, and linear simulation for fracture toughness value KQ determination. The suggested method is validated by comparing numerical and experimental tests results. The secondary aim of the paper is the evaluation of the ageing effect on the fracture toughness of steel P91. Thermal ageing of the steel was carried out in an electric furnace at 650 °C up to 11,000 h. As the numerical results had a good coincidence with experimental data at room temperature, the prediction of fracture toughness at elevated temperature, i.e., 550 °C, using numerical method was carried out.

scholarly journals Theoretical justification for the development of computer model of MDF structure and its milling process

2021 ◽  
Vol 2094 (4) ◽  
pp. 042043
Author(s):  
T V Efimova ◽  
T L Ischenko
Keyword(s):  
Computer Model ◽  
Milling Process ◽  
Point Of View ◽  
Theoretical Point ◽  
The Finite Element Method ◽  
Theoretical Justification ◽  
Operating Modes ◽  
Energy Indicators

Abstract The main parameter for determination of quality of MDF boardprocessing after milling is roughness of the surface. The well-known models of wood cutting are unsuitable for the assessment of this parameter, since they make it possible to draw only qualitative conclusions about the roughness, they do not allow calculating the numerical value. To calculate the roughness value, the model must take into account the structure of the material and the main parameters affecting the roughness. The purpose of this work is to substantiate the development of a computer model of the MDF structure and the process of its milling using the finite element method. The implementation of this approach will allow, according to the specified parameters of the cutter and modes of its operation, to determine the quality and energy indicators of the milling process from a theoretical point of view. As a result of the work carried out, a detailed theoretical justification for the development of a computer model of MDF structure and the process of its milling was given. Its implementation makes it possible to determine the quality and energy parameters of the milling process according to the specified parameters of the cutter and its operating modes.

scholarly journals Experimental and Numerical Assessment of Supporting Road Signs Masts Family for Compliance with the Standard EN 12767

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 5999
Author(s):  
Michał Stopel ◽  
Artur Cichański ◽  
Nathalie Yague ◽  
Grzegorz Kończalski
Keyword(s):  
Numerical Models ◽  
Product Family ◽  
Experimental Tests ◽  
Severity Index ◽  
Point Of View ◽  
Passive Safety ◽  
Road Signs ◽  
Numerical Assessment ◽  
The Impact ◽  
Crash Tests

The analysis aimed to assess the passive safety of supporting masts for road signs in accordance with EN 12767. Experimental tests were carried out based on the requirements of the standard for the smallest and the largest constructions within the product family. Numerical models of crash tests were prepared for whole product family using the Finite Element Method in the LS-Dyna environment. Based on the comparison of the experimental tests and the numerical calculations, the usefulness of the numerical model for estimating the actual value of the Acceleration Severity Index (ASI) and the Theoretical Head Impact Velocity (THIV) was assessed. With the use of these relationships the values of ASI and THIV for masts not tested experimentally were estimated. It was confirmed that the analyzed masts met the requirements for the passive safety of structures set out in the standard EN 12767. It was possible since as a result of the impact, the mast column detached from the base, allowing the vehicle to continue moving. The behavior of the masts was primarily influenced by the destruction of the safety connectors. The paper presents the most important elements from the point of view of designing such solutions.

scholarly journals Pavement Maintenance Management Application for Road Network in Romania

2019 ◽  
Vol 8 (2) ◽  
pp. 73-88
Author(s):  
Toma Mihai Gabriel ◽  
Mihai Dicu
Keyword(s):  
Road Network ◽  
Evaluation Process ◽  
Point Of View ◽  
Sufficient Information ◽  
Pavement Maintenance ◽  
The Road ◽  
Microsoft Access ◽  
Public Road ◽  
Technical Status

Abstract Maintaining the conditions for optimum exploitation of road networks is one of the primary activities of their administrators. The basic elements for establishing the decision-making act, are obtained by the correct evaluation, from the technical and financial point of view, of what is necessary for the normal unfolding, without interruptions, and in complete safety, of the car traffic. In the evaluation process, the managers must have at their disposal sufficient information, regarding the technical status of the road network from the administration, when and where it is appropriate to intervene and what maintenance and repairs operations should be performed. Only in this way, road managers will be able to adopt the appropriate strategy so that the investment reaches the highest rate of return and of course falls within the limits of the allocated funds. This paper presents A.D.T.S. (Automatic Determination of the Technical Status) application, designed using the Microsoft Access program. The application allows the determination of the technical status of the roads, storage, retrieval, updating and verification of information regarding the technical status of the roads. The information is kept in a road reference table, as a storage model in data banks, which can be used by public road administrators in their work, regarding the scheduling of works and justifying the need to finance road intervention works.

scholarly journals Determination of the Rayleigh damping coefficients of steel bristles and clusters of bristles of gutter brushes

DYNA ◽  
2015 ◽  
Vol 82 (194) ◽  
pp. 230-237
Author(s):  
Libardo Vicente Vanegas Useche ◽  
Magd M Abdel Wahab ◽  
Graham A Parker
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Experimental Tests ◽  
The Road ◽  
Damping Coefficients ◽  
Dynamic Finite Element ◽  
Rayleigh Damping ◽  
Dynamic Analyses ◽  
Effective Operation

Street sweeping is an important service that is usually performed by lorry-type vehicles that have a gutter brush, which is comprised of clusters of steel bristles that sweep the debris found in the road gutter. Effective operation of this brush is important, as most of the debris on roads is located in the gutter. In order to model a gutter brush by means of finite element dynamic analyses, it is necessary to determine appropriate values of the Rayleigh damping coefficients of both individual bristles and clusters of bristles. This paper presents the methodology and results of experimental tests that have been conducted to determine these coefficients. The results obtained are useful when studying the performance of conventional and oscillatory street sweeper gutter brushes by means of dynamic finite element modeling.

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