Assessing the performance of earthquake-resistant structural and geotechnical systems is crucial for achieving a desired reliability level and enhancing the resilience of the built environment in seismic-prone regions. Nonlinear dynamic analyses are widely used to quantify structural and geotechnical performance. Still, they require an accurate representation of nonlinear behaviours and proper modelling of the expected seismic events. Stochastic approaches are popular strategies for modelling dynamic actions to account for the uncertain nature of ground shaking. In this framework, joint time–frequency signal representations of seismic records are powerful tools to analyze signals’ time-varying amplitude and frequency content. This paper presents a new method for the stochastic generation of artificial accelerograms using the circular harmonic wavelet transform, which possesses joint time–frequency localization capabilities and offers the engineers a clear and transparent interpretation of the results. The proposed approach adopts a new exponential auto-correlation structure for generating the random phases in the “child (generated) signals” starting from the deterministic ones in the “parent record”. The effects of the correlation structure and different subdivisions of earthquake records in frequency bands are investigated and discussed, leading to practical considerations for identifying an effective trade-off between localization in time and frequency domains. The method can be used for seismic assessment and design purposes, and numerical applications illustrate its potency.

中文翻译：

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基于小波的完全非平稳随机过程的生成及其在地震地面运动中的应用


评估抗震结构和岩土系统的性能对于实现所需的可靠性水平和增强地震多发地区建筑环境的恢复能力至关重要。非线性动力分析广泛用于量化结构和岩土性能。尽管如此，它们仍然需要非线性行为的准确表示和预期地震事件的正确建模。随机方法是对动态行为进行建模以解释地面震动的不确定性的流行策略。在此框架中，地震记录的联合时频信号表示是分析信号随时间变化的幅度和频率内容的有力工具。本文提出了一种使用圆谐波小波变换随机生成人工加速度图的新方法，该方法具有联合时频定位能力，并为工程师提供了对结果清晰透明的解释。所提出的方法采用一种新的指数自相关结构，从“父记录”中的确定性信号开始生成“子（生成）信号”中的随机相位。研究和讨论了频带中地震记录的相关结构和不同细分的影响，从而为确定时域和频域定位之间的有效权衡提供了实际考虑。该方法可用于地震评估和设计目的，数值应用说明了其效力。