Showing 3 results for Type of Study: Technical note
S. Kazemzadeh Azad, S. Kazemzadeh Azad, O. Hasançebi,
Volume 6, Issue 4 (10-2016)
Abstract
Beginning in 2011 an international academic contest named as International Student Competition in Structural Optimization (ISCSO) has been organized by the authors to encourage undergraduate and graduate students to solve structural engineering optimization problems. During the past events on the one hand a unique platform is provided for a fair comparison of structural optimization algorithms; and on the other hand it is attempted to draw the attention of students to the interesting and joyful aspects of dealing with optimization problems. This year, after five online events successfully held with support and help of our advisory and scientific committee members from different universities all around the world, the authors decided to gather the test problems of the ISCSO in this technical report as an optimization test set. Beside the well -known traditional benchmark instances, the provided test set might also be used for further performance evaluation of future structural optimization algorithms.
N. Yaghoobi , B. Hassani,
Volume 7, Issue 1 (1-2017)
Abstract
Keeping the eigenfrequencies of a structure away from the external excitation frequencies is one of the main goals in the design of vibrating structures in order to avoid risk of resonance. This paper is devoted to the topological design of freely vibrating continuum structures with the aim of maximizing the fundamental eigenfrequency. Since in the process of topology optimization some areas of domain can potentially be removed, it is quite possible to encounter the problem of localized modes. Hence, the modified Solid Isotropic Material with Penalization (SIMP) model is here used to avoid artificial modes in low density areas. As during the optimization process, the first natural frequency increases, it may become close to the second natural frequency. Due to lack of the usual differentiability of the multiple eigenfrequencies, their sensitivity are calculated by the mathematical perturbation analysis. The optimization problem is formulated by a variable bound formulation and it is solved by the Method of Moving Asymptotes (MMA). Two dimensional plane elasticity problems with different sets of boundary conditions and attachment of a concentrated nonstructural mass are considered. Numerical results show the validity and supremacy of this approach.
F. Rahimi,
Volume 10, Issue 4 (10-2020)
Abstract
By incorporating structural engineering, animal husbandry, and veterinary, this interdisciplinary research accomplishes the following two main objectives: 1) design and optimization to reduce the weight of the steel structure skeleton of the stable with ECBO & CBO algorithms; 2) improving the performance of the natural ventilation system in the stable with some changes in the structure's geometric design.
In this study, each algorithm's performance will be investigated in the course of accomplishing the aforementioned objective. Furthermore, using stress ratios by algorithms in each member will be studied. Finally, using the algorithms, a stable steel structure with lower weight is designed.
In this paper, through changing and improving the structure's geometric design, a structure more compatible with the natural ventilation system's requirements is designed. These changes are as follows: 1) design of a taller stable structure; 2) larger design of the air inlets in the joint line between the upper part of the side walls and the lower part of the pitched roof.