Nonlinear random vibration analysis methods for the design of dynamic MDOF structural systems subject to seismic hazard

对不确定性进行适当的量化处理是对工程系统和结构的行为和可靠性进行可靠的数值预测的基本前提。在随机结构动力学领域，在过去的几十年里，人们已经认识到，地震等自然灾害造成的荷载可以在随机的基础上得到充分的表示。大多数现代抗震规范的规定都包含了对结构化设施设计的随机/概率处理。此外，在实际的结构和机械系统中，非线性以各种形式出现，并且通常随着振动幅度的增加而逐渐变得更加显著。具体地说，在抗震设计中，这样的问题相当容易出现。这种情况要求工程系统和结构的设计需要一种连贯的方法，其中结合了适当的不确定性量化和非线性力学。该项目通过开发一个通用的随机动力学框架来满足这一研究需求，该框架可以根据现代抗震规范对结构系统进行有效的响应确定、可靠性评估和基于性能的分析/设计。在技术方面，开发的重点是解决关键问题，即捕捉地震危险的内在随机性，并在考虑复杂的非线性/滞回材料行为的情况下分析结构和系统。该项目的学术影响将是广泛和多方面的，因为它位于土木工程/结构工程、应用数学、概率和统计学的交叉点上。该项目的成果预计将对各种动态系统/结构/设备的分析和设计产生重大影响，并将打开主要障碍，开启新兴和变革性技术的大量应用，例如在能量耗散(例如振动抑制)、能源生产(例如能量收集动态吸振器的分析/设计)和多尺度工程领域。在实践方面，该项目旨在弥合先进的随机工程动力学与当代设计规范条款(例如EC8)之间的主要差距，使其在概念上与基于性能的工程内容保持一致，并将导致在存在不确定性的情况下分析和设计现代工程结构/装置的方式发生范式转变。预计所设想的高效随机动力学框架将有助于实现工程系统的简约建模、大幅降低成本以及降低风险和总体失效概率。总体而言，这一跨学科项目将有助于结构动力学、概率方法、基于性能的工程、规范规定以及结构安全和可靠性等多个领域。

A proper quantitative treatment of uncertainties is a fundamental prerequisite to derive reliable numerical predictions of the behavior and reliability of engineering systems and structures. In the field of stochastic structural dynamics, it has been realized over the past decades that loads caused by natural hazards, such as earthquakes, might be adequately represented on a stochastic basis. Most contemporary aseismic code provisions incorporate a stochastic/probabilistic treatment for the design of structured facilities. Further, in real structural and mechanical systems nonlinearities arise in various forms, and usually become progressively more significant as the amplitude of vibration increases. Specifically, in earthquake resistant design such issues fairly emerge. This situation necessitates a coherent approach for designing engineering systems and structures, in which proper uncertainty quantification and nonlinear mechanics are combined.This research need is addressed in the project by developing a versatile stochastic dynamics framework for efficient response determination, reliability assessment, and performance-based analysis/design of structural systems subject to excitations in correspondence with contemporary aseismic codes.On the technical side, the development is concentrated on solving key questions of capturing the inherent stochastic nature of seismic hazards and analyzing structures and systems under such loads considering complex nonlinear/hysteretic material behavior. The academic impact of the project will be broad and multifaceted, since it lies in the intersection of civil/structural engineering, applied mathematics, probability and statistics. The findings from this project are expected to have a major impact on the analysis and design of diverse dynamic systems/structures/devices and will open major roadblocks and unlock a vast array of applications in emerging and transformative technologies, e.g. in the areas of energy dissipation (e.g. vibration suppression), energy generation (e.g. analysis/design of energy harvesting dynamic vibration absorbers) and multi-scale engineering. On the practical side, the project is supposed to close the major gap between advanced stochastic engineering dynamics and contemporary design code provisions (e.g., EC8) in conceptual agreement with the performance-based engineering content, and will cause paradigm shift in the way modern engineering structures/devices are analysed and designed under the presence of uncertainties. It is expected that the envisioned efficient stochastic dynamics framework will contribute towards achieving parsimony in modeling, substantial cost reduction as well as reducing the risk and the overall probability of failure for engineering systems.Overall, this cross-disciplinary project will contribute to diverse fields such as structural dynamics, probabilistic methods, performance-based engineering, code provisions, and structural safety and reliability.