Fatigue Analysis of Reinforced Concrete Bridge A Comparative Study of Analytical and Numerical Methods
Typ
Examensarbete för masterexamen
Program
Publicerad
2022
Författare
Okorie, Chidiebere Anthony
Ifechukwude, Abah
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
To regulate engineering practices, produce a uniform and sustainable structure in
a society, code and ethics were introduced in engineering practices. With regular
changes and developments, come increasing demands for more durable, safer, cost
effective and sustainable structures in the society. Hence, code of engineering prac tice undergo routine update. Recently, the European code (Eurocode) of practice
is at review process. Assessment of fatigue life of a structure is one of the areas
in review. Fatigue failure of a structure as a results of varying cyclic loading from
traffic, wind or ocean waves etc are characterised with a localised fracture in the
structure.
It is important to understand the effects of the changes introduced in the code of
practice prior to its full use. Fatigue assessment often governs in design of the
structures that will be subjected to cyclic loading. The purpose of this study is to
investigate effect of changes in fatigue assessment in the upcoming Eurocode (2000
EC.). Study the fatigue verification methods and compare with out dating version
(1990 EC.) and Fib model code and make parametric study.
There are three methods of fatigue assessment in Eurocode; the Damage Equiva lent (DEM), Simplified and Cumulative Damage Methods (CDM).These methods
assesses reinforcement and concrete separately. In this study, a simply supported
girder of a reinforced concrete road bridge was used. The beam span was varied for
the study with same conditions, Ultimate Limit State and Serviceability Limit State
designs made and with the three fatigue verification methods, fatigue assessments
was carried out.
The results of the comparative and parametric analysis showed that the methods
were similar in behaviour with varying magnitude. With damage equivalent method,
the 2000 EC required higher percentage increase in area of reinforcement up to 30%
difference compare to 1990 EC. Comparing codes with simplified method, in 2000
EC. the concrete grade required to satisfy fatigue in beam spans were lower than that
of 1990 EC. and Fib Model Code. From the parametric studies, fatigue strength in
RC. beam can be improved in the following ways; increase in area of reinforcement,
increase in concrete class, reduction in span length and selection of steel of higher
resisting stress. Increase in the amount of reinforcement results in environment
impact such as increased CO2 emission and cost.
Beskrivning
Ämne/nyckelord
Fatigue Analysis of Reinforced Concrete Bridge A Comparative Study of Analytical and Numerical Methods