A Whole-Range S–N Curve for Fatigue Assessment of Steel Orthotropic Bridge Decks

2018 ◽  
Vol 18 (08) ◽  
pp. 1840010 ◽  
Author(s):  
Guang-Dong Zhou ◽  
Ting-Hua Yi ◽  
Tai-Yong Zhu ◽  
Huan Zhang
Keyword(s):  
Bridge Decks ◽  
Point Of View ◽  
Steel Bridge ◽  
Traffic Loading ◽  
Fatigue Assessment ◽  
Proposed Model ◽  
The Mathematical Model ◽  
Very High ◽  
Double Logarithm

The fatigue assessment of orthotropic bridge decks under routine traffic loading is a significant task to ensure the serviceability and safety of steel bridges. The sequential law computes fatigue damages using whole-range [Formula: see text]–[Formula: see text] curves and sequential stress histories and has been proven to provide more realistic results than Miner’s rule under variable amplitude loading. In this paper, a whole-range [Formula: see text]–[Formula: see text] curve covering the very low-cycle region, the low-cycle region, the finite life region, the high-cycle region, and the very high-cycle region is proposed for the sequential law to evaluate the fatigue performance of steel orthotropic bridge decks. The mathematical model of the whole-range [Formula: see text]–[Formula: see text] curve is first deduced based on the partially known [Formula: see text]–[Formula: see text] curve recommended in steel bridge design codes. The properties of the whole-range [Formula: see text]–[Formula: see text] curve are then explained from the geometrical point of view in the double logarithm coordinates system. Finally, rib-to-deck joints in steel orthotropic bridge decks are used as a case study. Fatigue test data are used to validate the proposed model. The whole-range [Formula: see text]–[Formula: see text] curve, with a 97.5% survival limit, is established for fatigue assessment of rib-to-deck joints in real bridges. The results show that the proposed whole-range [Formula: see text]–[Formula: see text] curve allows a good fit of experimental data and excellent agreement with code [Formula: see text]–[Formula: see text] curves in the finite life region and provides an effective extrapolation from the finite life region to the whole range of cycle numbers.

scholarly journals Design of a sustainable polygeneration microgrid for the retrofitting of an industrial site: Ansaldo Energia case study

2019 ◽  
Vol 113 ◽  
pp. 03009
Author(s):  
Enrico Bianchi ◽  
Stefano Bracco ◽  
Fabio Cannizzaro ◽  
Federico Delfino ◽  
Alessandro Giacchino
Keyword(s):  
Industrial Area ◽  
Point Of View ◽  
Industrial Site ◽  
General Validity ◽  
Metropolitan City ◽  
Proposed Model ◽  
The University ◽  
Energy Infrastructures

The aim of this paper is that of proposing a methodology on how to design a microgrid for an industrial area. In particular, the paper reports the description of a project, jointly developed by the University of Genoa and Ansaldo Energia SpA, to design a polygeneration microgrid for the industrial site of Ansaldo Energia company in the Metropolitan City of Genoa. The microgrid infrastructure integrates different technologies to satisfy the electrical, thermal and cooling demand of the site, among which an important role is played by the cogeneration AE T100 microturbines developed by the company. In the paper, the optimization tool AEN-MGD, developed to optimally design and operate the microgrid, is described and different possible configurations of the microgrid are investigated and analysed from the technical, economic and environmental point of view. The proposed model has a general validity and it can be used to design and operate other similar energy infrastructures.

Designing differential service strategy for two-dimensional warranty based on warranty claim data under consumer-side modularisation

2019 ◽  
Vol 234 (3) ◽  
pp. 550-561
Author(s):  
Tong Peng ◽  
Liu Chunling
Keyword(s):  
Service Providers ◽  
Claim Data ◽  
Two Dimensional ◽  
Function Type ◽  
Service Strategy ◽  
Actual Usage ◽  
Proposed Model ◽  
Warranty Service ◽  
The Mathematical Model

With the development of modular manufacturing technology and diversified demand for products, the demand for differential warranty service has become increasingly prominent. This article proposes a differential service strategy for two-dimensional warranty using warranty claim data under consumer-side modularisation. In contrast to previous research that optimised maintenance strategies under a given failure density function, this article obtains actual usage rate and failure density functions of main failure types by determining the function type and parameter fitting. A detailed case study of a product under a two-dimensional warranty is discussed to interpret the proposed model. Using the mathematical model proposed in this research, warranty service providers can offer consumers a differential warranty service under consumer-side modularisation.

Fatigue assessment of orthotropic steel bridge decks based on strain monitoring data

2021 ◽  
Vol 228 ◽  
pp. 111437
Author(s):  
Jin Di ◽  
Xiaozheng Ruan ◽  
Xuhong Zhou ◽  
Jie Wang ◽  
Xi Peng
Keyword(s):  
Bridge Decks ◽  
Monitoring Data ◽  
Steel Bridge ◽  
Fatigue Assessment ◽  
Strain Monitoring

scholarly journals DETERMINING FACTORS OF INNOVATIVE PERFORMANCE: MULTIPLE CASE STUDY

2020 ◽  
Author(s):  
Beatriz Corchuelo Martínez-Azúa ◽  
◽  
Pedro E. López-Salazar ◽  
Celia Sama-Berrocal ◽  
◽  
...  
Keyword(s):  
Manufacturing Industry ◽  
Point Of View ◽  
Case Study Methodology ◽  
Innovative Strategy ◽  
Innovative Performance ◽  
Proposed Model ◽  
Determining Factors ◽  
Multiple Case ◽  
Study Methodology

The agri-food industry plays an important role in the manufacturing industry in the Autonomous Community of Extremadura (Spain). The objective of this research is to identify which factors influence the success of the innovative performance in this regional industry. For this, a case study methodology was designed to analyze, from an organizational point of view, which elements contribute to the ability of various companies to develop an innovative strategy. This study validates the proposed model in which Management, Strategy, Structure, Culture, Climate and Market Orientation are factors that determine innovative Performance.

scholarly journals Rehabilitation of Blue Nile Steel Bridge Superstructure: Fatigue Assessment

2021 ◽  
Vol 9 (1) ◽  
pp. 20-29
Author(s):  
Ali Hussein Mohamed Ali ◽  
Aws Zakaria Basheer Emam
Keyword(s):  
Fatigue Life ◽  
Rehabilitation Program ◽  
Railway Track ◽  
Steel Bridge ◽  
Blue Nile ◽  
Fatigue Assessment ◽  
Railway Traffic ◽  
Bridge Superstructure ◽  
Remaining Fatigue Life

The Blue Nile Steel Bridge over the Blue Nile River in Khartoum, Sudan, has been in service for 112 years. A riveted steel through-truss of Pettit Configuration with seven equal fixed spans of 65.53 m and a rolling lift span. The bridge currently accommodates approximately 61,000 vehicles per day along with insignificant pedestrian and railway traffic. Over the years from 1960 to 2014 several assessment studies were carried out by numerous parties have revealed that under cyclic loading of a long period time and effects of natural and man-made disasters, bridge deck was damaged severely and needed to be repaired and strengthened. A rehabilitation program was planned to extend the design life of the bridge for a more 50 years, which was carried out in period (2017 - 2018).This paper presents as a case study including a literature review on fatigue assessment of stringers on railway track. The rationale for selecting the rehabilitation strategy for the bridge is described, highlighting the challenging design aspects related to fatigue assessment, clarifying the methodology in which main members were identified for strengthening, using Midas Civil 2006 v7.01 and Midas FEA 2016 v1.1software to analyze the fatigue in the critical members by generating a model using Finite Element Method and estimating remaining fatigue life by adopting the classical approach (Stress-life method), the total damage accumulation was found greater than 1. Thus, it can be concluded that the stringers have no remaining fatigue life. Strengthening the stringers is considered the most favorable solution.  

THE DEVELOPMENT OF THE MATHEMATICAL MODEL OF PREDICTING THE INDICATORS OF ACCREDITATION OF TECHNICAL UNIVERSITIES IN THE RUSSIAN FEDERATION

2017 ◽  
pp. 27-38
Author(s):  
Olga Mikhaylovna Tikhonova ◽  
Alexander Fedorovich Rezchikov ◽  
Vladimir Andreevich Ivashchenko ◽  
Vadim Alekseevich Kushnikov
Keyword(s):  
Mathematical Model ◽  
System Dynamics ◽  
Regression Model ◽  
Oriented Graph ◽  
Real Data ◽  
Educational Process ◽  
Proposed Model ◽  
Linear Differential ◽  
The University ◽  
The Mathematical Model

The paper presents the system of predicting the indicators of accreditation of technical universities based on J. Forrester mechanism of system dynamics. According to analysis of cause-and-effect relationships between selected variables of the system (indicators of accreditation of the university) there was built the oriented graph. The complex of mathematical models developed to control the quality of training engineers in Russian higher educational institutions is based on this graph. The article presents an algorithm for constructing a model using one of the simulated variables as an example. The model is a system of non-linear differential equations, the modelling characteristics of the educational process being determined according to the solution of this system. The proposed algorithm for calculating these indicators is based on the system dynamics model and the regression model. The mathematical model is constructed on the basis of the model of system dynamics, which is further tested for compliance with real data using the regression model. The regression model is built on the available statistical data accumulated during the period of the university's work. The proposed approach is aimed at solving complex problems of managing the educational process in universities. The structure of the proposed model repeats the structure of cause-effect relationships in the system, and also provides the person responsible for managing quality control with the ability to quickly and adequately assess the performance of the system.

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