Kriegesmann, BenediktBenediktKriegesmannKrüger, Jan ChristophJan ChristophKrügerSteltner, KaiKaiSteltnerSchmidt, Timo HendrikTimo HendrikSchmidtSeifried, RobertRobertSeifried2025-11-242025-11-242025-11-15Structural and Multidisciplinary Optimization 68 (12): 242 (2025)https://hdl.handle.net/11420/58994This paper shows how a combination of multiple linear approximations can efficiently capture nonlinear and non-smooth response functions in the framework of robust design optimization. The basic idea is to split the domain of random parameters into multiple subdomains along discontinuities of the response. For each subdomain, a linear approximation is used to determine the stochastic moments of the response function due to the scatter in that subdomain. The total stochastic distribution of the structural response is considered to be a multimodal distribution, and its moments are composed of the approximations in the subdomains. The application to use cases shows that indeed the structural response is multimodal in these cases, and the stochastic moments are shown to be sufficiently accurate using the proposed method.en1615-1488202512Springerhttps://creativecommons.org/licenses/by/4.0/Multimodal responseProbabilistic analysisRobust design optimizationTaylor series approximationTechnology::624: Civil Engineering, Environmental Engineering::624.1: Structural Engineering::624.17: Structural Analysis and DesignJournal Articlehttps://doi.org/10.15480/882.1621710.1007/s00158-025-04191-910.15480/882.16217Journal Article