Fluid viscous dampers, if properly sized and placed, can significantly improve the performance and safety of existing structures during an earthquake. This has motivated the development of several approaches to optimize the design of fluid viscous dampers. The optimization approaches available typically have an iterative nature, and in every iteration, expensive time-history analyses are performed. This paper presents a novel optimization-based approach for retrofitting hysteretic structures with fluid viscous dampers that does not require the computation of time-history analyses. The sizing and placement of the dampers are defined using a simultaneous analysis and design optimization approach based on nonlinear programming. In this approach, the equations of motion are treated as equality constraints of the optimization problem. As a consequence, design sensitivity analysis methods are not needed to calculate the gradients of the objective and constraint functions. Two design scenarios are considered: structures with hysteretic behavior retrofitted with linear or nonlinear fluid viscous dampers. The optimization variables include the damping coefficients of the dampers and the structural response over time. The manufacturing cost of the dampers is minimized, with constraints on the inter-story drifts. A continuation scheme on the design-driving inter-story drift constraints is proposed to effectively solve the class of problems considered. The numerical results demonstrate that the proposed approach can solve complex design optimization problems using reasonable computational resources and time. It is also shown that, thanks to the proposed approach, additional constraints can be incorporated in the problem formulation with minimal modeling effort, and without the need to develop additional sensitivity analyses for computing the gradients of the added constraints. The Julia codes used in this study are freely available on GitHub: .

中文翻译：

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流体粘滞阻尼器滞回结构抗震加固的同步分析与设计优化

如果尺寸和位置正确，流体粘滞阻尼器可以显着提高现有结构在地震期间的性能和安全性。这促使人们开发出多种方法来优化流体粘性阻尼器的设计。可用的优化方法通常具有迭代性质，并且在每次迭代中，都会执行昂贵的时间历史分析。本文提出了一种基于优化的新颖方法，用于使用流体粘性阻尼器改造迟滞结构，该方法不需要时程分析的计算。使用基于非线性编程的同步分析和设计优化方法来确定阻尼器的尺寸和位置。在这种方法中，运动方程被视为优化问题的等式约束。因此，不需要设计灵敏度分析方法来计算目标函数和约束函数的梯度。考虑两种设计方案：用线性或非线性流体粘性阻尼器改造具有迟滞行为的结构。优化变量包括阻尼器的阻尼系数和结构随时间的响应。由于层间位移受到限制，阻尼器的制造成本得以最小化。提出了设计驱动层间位移约束的延续方案，以有效解决所考虑的此类问题。数值结果表明，所提出的方法可以使用合理的计算资源和时间解决复杂的设计优化问题。它还表明，由于所提出的方法，可以用最少的建模工作将附加约束纳入问题表述中，并且无需开发附加的敏感性分析来计算附加约束的梯度。本研究中使用的 Julia 代码可在 GitHub 上免费获取：。