n. khavaninzadeh

Diagrids are of practical interest in high-rise buildings due to their architectural configuration and efficiency in withstanding lateral loads by exterior diagonal members. In the present work, diagrid models are screened based on a sizing optimization approach. Section index of each member group is treated as a discrete design variable in the optimization problem to be solved. The structural constraints are evaluated due to Load and Resistant Design Factor regulations under both gravitational and wind loadings. The research is threefold: first, falcon optimization algorithm is utilized as a meta-heuristic paradigm for such a large-scale and highly constrained discrete problem. Second, the effect of geometry variation in diagrids on minimal structural weight is studied for 18 diagrid models via three different heights (12, 20 and 30 stories) and three diagrid angles. Third, distinct cases of rigid and flexible bases are compared to study the effect of such boundary conditions on the results. The effect of soil flexibility beneath the foundation on the optimal design was found highly dependent on the diagrid geometry. The best weight and performance in most of the treated examples belong to the geometry that covers two stories by every grid line on the flexible-base.

In this paper, a neural network is trained for optimal nodal ordering of graphs to obtain a small wavefront using soft computing. A preference function consists of six inputs that can be seen as a generalization of Sloan's function. These six inputs represent the different connection characteristics of graph models. This research is done with the aim of comparing Sloan's theoretical numbering method with Sloan's developed method with neural networks and WSA meta-heuristic algorithm. Unlike the Sloan algorithm, which uses two fixed coefficients, six coefficients are used here, based on the evaluation of artificial neural networks. The weight of networks is obtained using Water Strider algorithm. Examples are included to demonstrate the performance of the present hybrid method.

Diagrids have received much attention in recent years as lateral-load resistant systems. Most of previous research works have modeled the structure on rigid foundations. It is while the present work takes into account the static soil-structure interaction in a planar 20-story example with a constant diagrid angle. A finite element program is provided for analyzing diagrid systems under a number of loading combinations including gravitational and lateral wind loadings. As the structural behavior depends on the distribution of section profiles among its members, sizing optimization is employed for screening the diagrid designs. Optimization is performed by a meta-heuristic algorithm inspired by hunting behavior of Falcons that samples the design space without need to any gradient calculation. The algorithm is recently developed in 2019 and applied for heat exchanger design. It simulates the hunting flight in: 1) logarithmic spiral flight in which the Falcon keeps its head straight looking sideways at the prey with maximum visual acuity, and 2) diving toward the prey by binocular vision. The first stage provides exploration while the second models search intensification in such a meta heuristic algorithm. In addition, the phenomena of klepto-parasitism between falcons is modeled to enhance the search. In order to apply both axial and flexural section properties in such a discrete problem, profile indices are taken as design variables. They are to be selected from the practical list of profiles during optimization. Member grouping is also employed to deserve symmetry and other practical considerations in the models. Consequently, diagrid design is fixed by minimizing the structural weight under code-based stress and deformation constraints. The designs are distinctly obtained for two cases of rigid and flexible soil-structure connections. By an external penalty approach, constraints are checked under simultaneous gravitational and wind loadings to be satisfied in the final optimal designs. Applying pushover analyses, various measures are studied and compared showing importance of soil-flexibility not only in the optimal costs but also in non-linear structural responses.

Partricular features of overpassing local optima and providing near-optimal soultion in practical time has led researchers to apply metaheuristics in several engineering problems. Optimal design of diagrids as one of the most efficient structural systems in tall buildings has been concerned here. Jaya algorithm as a recent paramter-less optimization method is employed to solve the problem using a set of available sections. Furthermore, passive congregation is embedded in Jaya without adding any extra control parameters. Applyig the method in a number of real-size structural examples including diagrids, exhibits performance improvement by the new hybrid algorithm with respect to Jaya.

Several landslides occur every year in the world, causing great damage to infrastructure and loss of life. Detection and monitoring of landslides is very important for implementing appropriate mitigation measure to reduce the loss of life and damage to property. Iran is prone to huge landslides due to its special continental conditions, topographic and tectonic situation and climate conditions. In this investigation, we use the technique of Interferometry Synthetic Aperture Radar (InSAR) to detect and monitor landslides in Taleghan region. The results are obtained from processing of 23 ASAR images acquired in the region by the Envisat satellite. We show evidence for several creeping landslides and obtain their deformation history between 2003 and 2009 via InSAR time-series analysis. We also report on our field investigation that we did to check the results of InSAR analysis.