Design solutions for structures with optimal internal stress distribution

Yurii Kitov,Maryna Verevicheva,Glib Vatulia,Svitlana Deryzemlia,Yevhen Orel,B Gigov,N Nikolov,M Todorov,V Stoilov

doi:10.1051/matecconf/201713303001

Yurii Kitov, Maryna Verevicheva + Show 7 more

Open Access

https://doi.org/10.1051/matecconf/201713303001

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Abstract

The development of transport infrastructure, reconstruction of roads and railways, together with growing urban traffic necessitate the construction of new bridges and/or the reconstruction of existing ones. The primary objective of design is obtaining a reasonable system in compliance with the requirements for stress-strain state: equal strength or equal torque, maximum rigidity or minimum weight of the structure. In the paper, the object of optimization is the design of a three-span girder bridge of a specified length under the constant load. The sets of both statically determinate and statically indeterminate systems are considered, namely: three-span hinged girders in which the hinge joints are located in the end spans or middle span, and three-span continuous girders on unilateral supports or on resilient supports. Two variable design parameters are taken into account: the length of each end span z 1 and the position of the hinges x for the statically determinate systems, and the displacement of support assemblies joints Δ or the value that affects the displacement, i.e. flexibility of yielding supports c for the statically indeterminate ones. The authors proved that there are optimal solutions in the set of statically indeterminate systems both with unilateral and with elastic constraints.

Highlights

IntroductionAlong with the development of new constructive solutions and methods for assessment of the stress-strain state and bearing capacity of building structures, the issue of optimizing their parameters is addressed now
Along with the development of new constructive solutions and methods for assessment of the stress-strain state and bearing capacity of building structures, the issue of optimizing their parameters is addressed now.In [1] three principles are described that underlie the design of steel constructions: metal saving, reduction of labour intensity of manufacture and installation time
Before methods of optimization appeared, methods of determining the weight depending on the design parameters of structures were developed

Summary

Introduction

Along with the development of new constructive solutions and methods for assessment of the stress-strain state and bearing capacity of building structures, the issue of optimizing their parameters is addressed now. In [1] three principles are described that underlie the design of steel constructions: metal saving, reduction of labour intensity of manufacture and installation time. In different periods, these principles were taken into account in different ways, depending on the state-of-theart in the industry and the urgent needs of society, as well as the existing structural engineering methods. Before methods of optimization appeared, methods of determining the weight depending on the design parameters of structures were developed. The only tasks in using the mathematical programming methods with problems of steel structure optimization were to minimize the girder and the plane frame weight. Problem statements got more complicated, in particular, including the transition to the economic optimality criteria, adjustment of the stressstrain state of construction, unification and typification of elements, which allowed bringing the optimization theory closer to the design practice in engineering, transport and construction [8-17]

General provisions

Optimization of the design of the three-span girder bridge

Continuous girder with hinge joints in the middle span

Conclusions