A new enhanced multi-modal pushover procedure based on the structural dynamic theory with a straightforward and easy-to-use algorithm is developed in this study for estimating the structural demands. The proposed method, which is called the multi-mode displacement-based pushover (MDP) procedure, consists of multiple single-run non-adaptive pushover analyses conducted using a range of enhanced displacement-based lateral load patterns proposed herein. These lateral load distributions are constructed by numerically adding and subtracting the modal displacement vectors modified using modification factors that are a function of the effective modal participating mass ratio (${\alpha }_n$). The final seismic demands in the proposed procedure are computed by enveloping the results obtained by several single-run pushover analyses. The MDP procedure has the ability to account for the higher mode effects into responses, sign reversal in the modal load vectors due to the contribution of higher modes as well as the non-concurrency of the maximum modal responses. Less computational effort and time cost, compared to the adaptive methodologies, is another advantage of the proposed procedure. The accuracy and efficiency of the MDP procedure in estimating the structural demands are validated by applying it on three steel special moment frames (SMFs) with different heights. The results demonstrate that the proposed procedure is successful in predicting the critical seismic demands with acceptable accuracy.

本研究开发了一种基于结构动力学理论的新型增强型多模态推覆程序，该程序具有简单易用的算法，用于估计结构需求。所提出的方法称为基于位移的多模态 Pushover (MDP) 程序，包括使用本文提出的一系列增强的基于位移的横向载荷模式进行的多次单次非自适应 Pushover 分析。这些侧向载荷分布是通过数值加减模态位移向量来构建的，这些模态位移向量是使用修正系数修正的，这些修正系数是有效模态参与质量比的函数（${\alpha }_n$）。建议程序中的最终抗震要求是通过将多个单次推覆分析获得的结果包络起来计算出来的。MDP 程序能够将较高的模态效应考虑到响应中，由于较高模态的贡献以及最大模态响应的非并发性，模态载荷向量中的符号反转。与自适应方法相比，更少的计算工作和时间成本是所提出的程序的另一个优点。通过将 MDP 程序应用于具有不同高度的三个钢特殊力矩框架 (SMF)，验证了 MDP 程序在估计结构需求方面的准确性和效率。结果表明，所提出的程序成功地以可接受的精度预测了临界地震需求。