A New Energy-Based Structural Design Optimization Concept under Seismic Actions
نویسندگان
چکیده
A new optimization concept is introduced which involves the optimization of non-linear planar shear buildings by using gradients based on equivalent linear structures, instead of the traditional practice of calculating the gradients from the non-linear objective function. The optimization problem is formulated as an equivalent linear system of equations in which a target fundamental eigenfrequency and equal dissipated energy distribution within the storeys of the building are the components of the objective function. The concept is applied in a modified Newton–Raphson algorithm in order to find the optimum stiffness distribution of two representative linear or non-linear MDOF shear buildings, so that the distribution of viscously damped and hysteretically dissipated energy, respectively, over the structural height is uniform. A number of optimization results are presented in which the effect of the earthquake excitation, the critical modal damping ratio, and the normalized yield inter-storey drift limit on the optimum stiffness distributions is studied. Structural design based on the proposed approach is more rational and technically feasible compared to other optimization strategies (e.g., uniform ductility concept), whereas it is expected to provide increased protection against global collapse and loss of life during strong earthquake events. Finally, it is proven that the new optimization concept not only reduces running times by as much as 91% compared to the classical optimization algorithms but also can be applied in other optimization algorithms which use gradient information to proceed to the optimum point.
منابع مشابه
AN EFFICIENT METHOD FOR OPTIMUM PERFORMANCE-BASED SEISMIC DESIGN OF FUSED BUILDING STRUCTURES
A dual structural fused system consists of replaceable ductile elements (fuses) that sustain major seismic damage and leave the primary structure (PS) virtually undamaged. The seismic performance of a fused structural system is determined by the combined behavior of the individual PS and fuse components. In order to design a feasible and economic structural fuse concept, we need a procedure to ...
متن کاملComparison of Seismic Input Energy Based on the Characteristics of Structural Hysteretic Behavior
The variation of earthquake input energy with characteristics of various structural systems, particularly in hysteretic states, has not been studied to such extent that creates enough con-fidence for proposing energy-based design criteria. In this paper, at first, based on a somehow new insight into the concept of earthquake input energy, two concepts of ‘Received Energy’ (ERec) and ‘Returned E...
متن کاملInnovations in Sustainable Earthquake Resisting Rocking Wall-Frames
This paper introduces a novel design concept for the development of efficient, sustainable Rocking-Wall Moment Frames (RWMFs) under seismic conditions. The proposed concepts lead to a novel structural configuration with provisions for Collapse Prevention (CP), Self-Centering (SC), reparability, performance control (PC), damage reduction, and energy based seismic analysis. It introduces the meri...
متن کاملSEISMIC ENERGY DEMANDS OF INELASTIC BUILDINGS DESIGNED WITH OPTIMUM DISPLACEMENT-BASED APPROACH
In present study, the effects of optimization on seismic energy spectra including input energy, damping energy and yielding hysteretic energy are parametrically discussed. To this end, 12 generic steel moment-resisting frames having fundamental periods ranging from 0.3 to 3s are optimized by using uniform damage and deformation approaches subjected to a series of 40 non-pule strong ground motio...
متن کاملSEISMIC OPTIMIZATION OF STEEL MOMENT RESISTING FRAMES CONSIDERING SOIL-STRUCTURE INTERACTION
The main purpose of the present work is to investigate the impact of soil-structure interaction on performance-based design optimization of steel moment resisting frame (MRF) structures. To this end, the seismic performance of optimally designed MRFs with rigid supports is compared with that of the optimal designs with a flexible base in the context of performance-based design. Two efficient me...
متن کامل