Extreme-Value Combination Rules for Tower–Line Systems Under Non-Gaussian Wind-Induced Vibration Response

Currently, extreme response analysis of tower–line systems typically assumes each component response follows a stationary Gaussian process. However, actual structural responses often exhibit significant non-Gaussian characteristics, potentially compromising structural safety during service life. Based on the first-passage theory and the complete quadratic combination (CQC) rule, this study investigates the extreme-value combination of non-Gaussian wind-induced responses for tower–line systems. Subsequently, wind tunnel test data are utilized to generate extreme-value samples with specified first four statistical moments through Monte Carlo simulation. An extensive parametric study was conducted to investigate the influence of non-Gaussian response components on combined extreme responses, leading to the development of a modified CQC (MCQC) rule for extreme-value estimation. Quantitative analyses incorporating both correlation coefficients and standard deviations demonstrated that among the classical combination rules, the proposed MCQC rule provides superior accuracy in estimating the total wind-induced response of tower–line systems. The validity of the MCQC rule was subsequently verified through wind tunnel test data, with the results showing excellent agreement between predicted and experimental values. The research results provide some reference for strengthening the wind resistance toughness of tower–line systems under wind load.