Topology optimization of horizontally curved box girder diaphragms

Nassr, Amr A.; Abd-el-rahim, Hamdy H. A.; Kaiser, Fayez; El-sokkary, Abd El-hady

doi:10.1016/j.engstruct.2022.113959

Cited by 7 publications

(3 citation statements)

References 23 publications

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“…In bridges having any important curve in them, the prestressed U-shaped girder is the best choice compared to other conventional types of bridges. Prestressed U-shaped girders are also used for aesthetic purposes [15,[18][19][20][21]. The prestressed U-shaped girder design was determined to provide superior resistance to collapse compared with multiple-plate girders because of its lower temperature rise and a higher moment resistance [22].…”

Section: Introductionmentioning

confidence: 99%

Cost Optimization of Prestressed U-Shaped Simply Supported Girder Using Box Complex Method

et al. 2023

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The use of U-shaped girders has become increasingly popular in advanced projects such as metro rail systems due to their ability to provide greater vertical clearance beneath bridges. These girders, characterized by two webs and a bottom flange, contribute essential longitudinal stiffness and strength to the overall structure while effectively countering torsional forces in curved bridges. However, the design and construction of U-shaped girders present challenges, including their relatively higher self-weight compared to other girder types. Consequently, cost optimization has become a crucial focus in structural design studies. This research aims to develop an optimization model for prestressed U-shaped girders using the AASHTO LRFD bridge design specifications. The model is based on the Box complex method, with necessary modifications and improvements to achieve an optimal design. The objective is to minimize the total cost of materials, including concrete, steel reinforcement, and prestressing strands, while satisfying explicit and implicit design constraints. To facilitate the analysis, design, and optimization processes, a program is developed using Visual Studio 2010 and implemented in Visual Basic (VB.NET). The program incorporates separate subroutines for analysis, design, and optimization of the prestressed U-shaped girder, which are integrated to produce the desired results. When running the program, the optimization process required 229 iterations to converge to the optimal cost function value. The results demonstrate that the developed algorithm efficiently explores economically and structurally effective solutions, resulting in cost savings compared to the initial design. The convergence rate of the moment capacity constraint is identified as a key factor in achieving the optimal design. This research makes a significant contribution to the field of civil engineering by applying the classical Box complex method to the optimization of girders, an area where its utilization has been limited. Furthermore, this study specifically addresses the optimization of prestressed U-shaped girders in metro rail projects, where they serve as both the deck and support structure for train loading. By employing the Box complex method, this research aims to fill the research gap and provide valuable insights into the optimization of U-shaped girders. This approach offers a fresh perspective on designing these girders, considering their unique role in supporting metro rail loads. By leveraging the benefits of the Box complex method, researchers can explore new possibilities and uncover optimal design solutions for U-shaped girders in metro rail applications.

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Section: Introductionmentioning

confidence: 99%

Cost Optimization of Prestressed U-Shaped Simply Supported Girder Using Box Complex Method

et al. 2023

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“…In industrialization, the large tonnage box girder has been widely used due to its large structural sti ness, fast construction speed, less joints, good durability, and easy maintenance [2]. In China, the large-tonnage box girders have been adopted in various projects like Hangzhou Bay Bridge, Donghai Bridge, and Jiaozhou Bay Bridge.…”

Section: Introductionmentioning

confidence: 99%

Simulation‐Based Tracking Test and Optimization of Large‐Tonnage Box Girder Transport with Trolley on an Erected Bridge

Wang

et al. 2022

Advances in Civil Engineering

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In the construction of large-tonnage box girder, the construction load of box girder transport is generally greater than the operating load in highway industry; therefore, it is a crucial task to carry out accurate simulation and optimization on bearing box girder. For this purpose, the refined modeling method of 40 m/1270t box girder is studied first in this paper, followed by detailed stress analysis by considering the impact coefficient of vehicles and the most unfavorable conditions. Tracking tests on dead load, prestressed load, and the transport load have shown that the calculated stress values obtained by the refined models are very close to the measured stress values. Based on dynamic strain test of the vehicles at the speed of 4 km/h, the impact coefficient of four vehicles is estimated to be 1.08 and its value meets the requirements of no more than 1.1 provided by the vehicle manufacturer. Aimed at no tensile stress in the midspan section, the optimized geometry of 40 m box girder is obtained with less concrete and longitudinal prestressed tendons. These results demonstrate the plausibility and validity of the proposed research methods and optimization schemes for large-tonnage box girder transport.

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“…In the past decades, topology optimization, 1,2 as a cutting-edge mathematical and mechanical theory, has been used to assist the design of reinforced concrete (RC) structures, especially for complex stressed components (such as deep beam 3,4 and box girder, 5,6 ) or joint. 7,8 Among various of topology optimization algorithms of continuum structures, evolutionary structural optimization type (ESO-type) algorithms, 9 and solid isotropic material penalty model type (SIMP-type) algorithms 10 have been thoroughly concerned and applied in recent years as their good convergence and stability.…”

Section: Introductionmentioning

confidence: 99%

Influence of feasible reinforcement domain on the topology optimization with discrete model finite element analysis

Luo

Zhang

Wang

2022

Structural Concrete

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In topology optimization with discrete model finite element analysis (FEA), feasible reinforcement domain determines to a large extent the result, and the trade-off between accuracy and efficiency of optimization as well. Therefore, a cantilever reinforced concrete short beam was comparatively optimized based on five feasible reinforcement domains with complexity at different levels, respectively. The outcomes exhibit that, it is reasonable to evolve reinforcement layout by topology optimization with discrete model FEA. The orientation of diagonal reinforcement in optimal topologies from complex feasible reinforcement domains would correspond more to the orientation of the principal tensile stress than that using simple ones, since complex ones have rebar distribution with high density or diagonal reinforcement with various orientations. After optimization, the global stress level of the reinforcement decreases, and then utilization rate of the reinforcement strength increases. Additionally, the consumption of rebar and the workload of reinforcement engineering only slightly increased, although such optimal reinforcement topologies are relatively complex. Consequently, the mechanical properties of concrete members can be substantially improved by using a more complex feasible reinforcement domain for optimizing rebar distribution. A complex domain should be chosen on the premise of completing the optimization within a reasonable time in engineering applications.

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Topology optimization of horizontally curved box girder diaphragms

Cited by 7 publications

References 23 publications

Cost Optimization of Prestressed U-Shaped Simply Supported Girder Using Box Complex Method

Cost Optimization of Prestressed U-Shaped Simply Supported Girder Using Box Complex Method

Simulation‐Based Tracking Test and Optimization of Large‐Tonnage Box Girder Transport with Trolley on an Erected Bridge

Influence of feasible reinforcement domain on the topology optimization with discrete model finite element analysis

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