Design optimization of truss structures using genetic algorithms

Download
2012
Ünalmış, Dilek
Design optimization of truss structures is a popular topic in aerospace, mechanical, civil, and structural engineering due to benefits to industry. Common design problem for the structures is the weight minimization. Especially in aerospace engineering the minimization of the weight of the total structure gets the highest importance in the design. This study focuses on the design optimization of 2D and 3D truss structures. The objective function is the total mass of the structure which is subjected to stress and nodal displacement constraints. To optimize the design, Genetic Algorithm (GA) is preferred due to its efficiency in dealing with problems with discrete design variables as in the case of truss structures. This technique yields more realistic results than linear programming methods. In the thesis, a finite element code is developed for the analysis of planar and space truss structures. The developed finite element solver is coupled with a genetic algorithm optimization code which is also developed as a part of the thesis study. Different truss optimization case studies are performed to demonstrate the performance of the finite element solver and the genetic algorithm optimization code that are developed. It is shown that with the use of adaptive penalty function employing scaled fitnesses, the arbitrariness issue of the factor multiplying the error term in the augmented fitness function can be resolved. It is also shown that significant weight reduction can v be achieved by employing shape optimization together with size optimization compared to pure size optimization.

Suggestions

Development of bolted flange design tool based on finite element analysis and artificial neural network
Yıldırım, Alper; Kayran, Altan; Department of Aerospace Engineering (2015)
In bolted flange connections, commonly utilized in aircraft engine designs, structural integrity and minimization of the weight are achieved by the optimum combination of the design parameters utilizing the outcome of many structural analyses. Bolt size, number of bolts, bolt locations, casing thickness, flange thickness, bolt preload, and axial external force are some of the critical design parameters in bolted flange connections. Theoretical analysis and finite element analysis (FEA) are two main approach...
Optimum design of steel space frames via bat inspired algorithm
Hasançebi, Oğuzhan (null; 2013-05-19)
Design optimization of steel space frames is a very popular topic in structural engineering due to economy saved in cost of the structures by optimization process. Although the final cost of a steel frame is affected by many factors, such as material, manufacturing, erection and transportation costs, the material cost of steel comprises a great deal of overall cost of the structure. Hence, the design optimization of steel frames is focused on weight minimization in the literature based on the assumption tha...
COMPARATIVE STRUCTURAL OPTIMIZATION STUDY OF COMPOSITE AND ALUMINUM HORIZONTAL TAIL PLANE OF A HELICOPTER
Arpacıoğlu, Bertan; Kayran, Altan (2019-11-11)
This work presents structural optimization studies of aluminum and composite material horizontal tail plane of a helicopter by using MSC. NASTRAN SOL200 optimization capabilities. Structural design process starts from conceptual design phase, and structural layout design is performed by using CATIA. In the preliminary design phase, study focuses on the minimum weight optimization with multiple design variables and similar constraints for both materials. Aerodynamic load calculation is performed using ANSYS ...
Technological characteristics of abrick masonry structure and their relationship with the structural behaviour /
Aktaş, Yasemin Didem; Türer, Ahmet; Department of Archaeometry (2006)
The aim of this study is to investigate the physical and mechanical properties of construction materials in relation with the structural behaviour of a historic structure. Within this framework, the brick masonry superstructure of Tahir ile Zuhre Mescidi, a XIIIth century Seljuk monument in Konya was selected as case study. The study started with the determination of the basic physical (bulk density, effective porosity, water absorption capacity), mechanical (modulus of elasticity, uniaxial compressive stre...
Design of a GaN Based Integrated Modular Motor Drive
Uğur, Mesut; Keysan, Ozan (2018-10-25)
In this study, design procedure of an Integrated Modular Motor Drive (IMMD) is presented focusing on high power density. The design is based on a permanent magnet synchronous motor (PMSM) and GaN FETs. Fractional slot concentrated windings are used on the stator. Slot/pole combination and winding configuration is selected based on having low cogging torque and high winding factor. An extended motor drive inverter topology is proposed where 2-level voltage source inverters are connected both in series and pa...
Citation Formats
D. Ünalmış, “Design optimization of truss structures using genetic algorithms,” M.S. - Master of Science, Middle East Technical University, 2012.