Seismic reliability analysis of a timber steel hybrid system. (15th July 2018)

• Record Type: Journal Article
• Authors: Zhang, Xiaoyue; Shahnewaz, Md; Tannert, Thomas
• Is Part Of: Engineering structures. Volume 167(2018)
• Page Start: 629
• Page End: 638
• Publication Date: 2018-07-15
• Subjects: Cross-laminated timber -- Finite element analyses -- Reliability analyses -- Response surface method -- Importance sampling -- Genetic algorithm -- Stepwise analysis of variance; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2018.04.051
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: Seismic reliability analyses are performed on a novel timber-steel hybrid system. Approaches to reduce computational effort for reliability analyses were studied. ANOVA and genetic algorithms are combined with response surface methods. Ground motion variability has highest impact on seismic structural reliability. Ductility, structural weight, hold-down and connection stiffness are significant. Abstract: Seismic reliability analyses account for the inherent uncertainties in both the actions (earthquakes) and the reactions (properties of the structural systems) of a structure. To predict the failure probability of a structure, the system response due to external loads is usually estimated by a numerical method. In this paper, seismic reliability analyses were performed on a novel timber-steel hybrid system labelled FFTT (Finding the Forest Through the Trees) system. The FFTT system utilizes mass-timber panels to resist gravity and lateral loads and interconnecting steel members to provide the necessary ductility for seismic demands. To reduce the computational effort for reliability analyses, Genetic Algorithms (GA) and Analysis of Variance in combination with response surface methods were applied and compared. Uncertainties involving ground motions, seismic weight, connection properties of the lateral load resisting system, and ductility factor were considered in formulating the performance functions. Mean and standard deviation of peak inter-storey drift were selected as performance criteria. Nonlinear dynamic analyses were run to generate the response database for the FFTT system and the reliability index was calculated using second-order reliability methods. The results showed that the GA method was superior and that the ground motion was the most significant factor for structural reliability, while the ductility factor, the structural weight, the hold-down and connection stiffness also played significant roles.