Seismic failure mode identification and multi-objective optimization for steel frame structure

In this study, a combined performance-based seismic failure mode identification and multi-objective optimization method is proposed, in which the failure probability function is introduced to identify the primary structural failure mode with a certain probability level, and the structural damage and hysteretic energy are taken as indices in the objective function to improve the structure’s seismic performance. Taking a 20-story steel frame structure as an example, seismic failure modes are identified and optimized using this method. Results indicate that global damage to the optimized structure is reduced under 62% earthquake excitations, while the hysteretic energy dissipation capacity of the optimized structure is improved under 48.3% earthquake excitations. Furthermore, the distribution of the optimized structure’s inter-story drift ratio is more uniform than in the original structure, leading to a significant improvement of the structural seismic performance.

Application of Intuitionistic Fuzzy Topsis Model for Troubleshooting an Offshore Patrol Boat Engine

In this paper, an Intuitionistic Fuzzy TOPSIS model which is based on a score function is proposed for detecting the root cause of failure in an Offshore Boat engine, using groups of expert’s opinions. The study which has provided an alternative approach for failure mode identification and analysis in machines, addresses the machine component interaction failures which is a limitation in existing methods. The results from the study show that although early detection of failures in engines is quite difficult to identify due to the dependency of their systems from each other. However, with the Intuitionistic Fuzzy TOPSIS model which is based on an improved score function such faults/failures are easily detected using expert’s based opinions.