Plastic Analysis Optimization of Moment Frames by Proposing a New Optimization Algorithm, Binary Dolphin Echolocation

The analysis of structures and, in particular, the determination of their failure mode is an essential requirement in the field of civil engineering. Obtaining this information in high-rise structures or structures with complex irregular layouts is a difficult process, which is very time-consuming even with the use of specialized computer software. In this research, a new optimization algorithm, named Binary Dolphin Echolocation Algorithm, is introduced by modifying the Dolphin Echolocation Optimization Algorithm. In recent years, meta-heuristic algorithms have been used extensively in engineering optimization problems. This research presents an automated approach to assess plastic loads and failure modes of 2D frames. The plastic analysis of moment frames has been optimized using the Binary Dolphin Echolocation Optimization Algorithm. Not only the proposed algorithm is applicable in this specific plastic analysis problem, but also it can be extensively used in any binary optimization problems. The method of elementary mechanism combination in the plastic analysis of moment frames is based on creating the basic collapse mechanisms, which, following their combination, should reach the minimum coefficient of plastic collapse loads. By using virtual work theory, the collapse load factor of each mechanism is achievable. The critical collapse load factor is then the minimum of them among all possible collapse mechanisms. The efficiency of this algorithm is verified using two frame samples with their exact response in the search for minimum load factors and their corresponding collapse mode. A comparison of the results shows that the proposed method provides outstanding results with high precision and speed and demonstrates the structure's failure mechanism. Meanwhile, the modifications made in this method have significantly reduced the volume of calculations. moreover, applying changes to the Dolphin Echolocation Optimization Algorithm led to the use of this optimization algorithm for binary problems for the first time, ultimately resulting in a good convergence rate.