Performance-based optimization of transmission lines subject to non-synoptic wind actions

• Grant number: 24/00102-2
• Support Opportunities: Scholarships in Brazil - Doctorate
• Effective date (Start): May 01, 2024
• Effective date (End): February 28, 2027
• Field of knowledge: Engineering - Civil Engineering - Structural Engineering
• Principal Investigator: André Teófilo Beck
• Grantee: Felipe Costa Macedo
• Host Institution: Escola de Engenharia de São Carlos (EESC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

Transmission lines (TL) are a very important part of our infrastructure. Their design is still mainly based on a single extreme value wind speed, evaluated from synoptic or mixed wind speed records, whereas non-synoptic (e.g. tornado and downbursts) winds are responsible for up to 80% of weatherrelated TL collapses. The proposed research project aims to fill this gap, employing the Performance-Based Engineering (PBE) methodology to search for optimal transmission line design solutions under non-synoptic wind actions following the risk optimization (RO) approach. However, PBE analyzes require a large amount of numerical simulations, to capture the nonlinear dynamic random response of TL structures, especially in the collapse prevention limit state. In this context, the optimal design of structures, with the objective of minimizing life cycle costs, significantly increases the computational burden. Therefore, the use of meta-modeling techniques is fundamental, allowing accurate but computationally viable solutions to challenging numerical problems. In particular, adaptive meta-modeling techniques will be explored to solve life cycle cost minimization problems within a PBE context. Such techniques are called Efficient Global Performance-Based Optimization (EGPBO). Non-synoptic wind hazard curves and structure fragility curves will be constructed, where performance will be characterized as the probability of exceeding different limit states. The resulting failure probabilities are used in the risk optimization solution to find the design which minimizes total expected life cycle costs, including costs or repair and reconstruction. It is expected that, as a consequence of using a more rational design procedure and exploring the different characteristics of non-synoptic winds, more economical and sustainable solutions can be found when compared to the traditional prescriptive design approach. Thus, the proposed research has practical relevance to the design of transmission lines excited by high-intensity winds. (AU)