Description of the spatial variability of concrete via composite random field and failure analysis of chimney基于复合随机场的混凝土空间变异性描述与烟囱失效分析
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Tao JJ, He JR, Xiong BB, Song YP, 2024. Description of the spatial variability of concrete via composite random field and failure analysis of chimney. Probabilistic Engineering Mechanics, 77: 103677.DOI: 10.1016/j.probengmech.2024.103677
混凝土的固有变异性会显著影响结构安全和性能。结构中混凝土的变异性是一种复杂现象，受材料特性、制备工艺和环境条件等多种因素的影响。研究并量化混凝土的变异性，对于可靠且安全的结构设计至关重要。在结构设计中，通常采用概率方法来表征混凝土的变异性。本文采用复合随机场方法结合层级模型来描述结构中混凝土的多层级空间变异性。在该方法中，混凝土抗压强度随机场被表示为多个独立分量随机场的叠加。为了研究混凝土空间变异性对结构响应和失效模式的影响，本文对一座115米高的烟囱进行了分析。结果表明，复合随机场方法能够有效整合混凝土在不同层级上的空间变异性。混凝土空间变异性对可能的受压损伤位置有显著影响。此外，烟囱的失效模式也受混凝土空间变异性的影响。当考虑空间变异性时，出现了一种新的倒塌模式，该模式与地震作用下烟囱的实际倒塌破坏更为接近。另外，混凝土的空间变异性还影响结构底部剪力和最大层间位移角的变异性。值得注意的是，若未能合理地考虑混凝土的空间变异性，可能会显著影响混凝土受压损伤和结构响应。关键词: 复合随机场, 空间变异性, 层级结构, 失效模式The inherent variability of concrete significantly affects the structural safety and performance. The variability of concrete is a complex phenomenon influenced by multiple factors, including material properties, production processes, and environmental conditions. Understanding and quantifying the variability of concrete is crucial for reliable and safe structural design. Probabilistic methods are commonly used to account for concrete variability in structural design. In this paper, a composite random field approach combined with a hierarchy model is used to consider the multi-scale spatial variability of concrete. The random field of compressive strength is expressed as a sum of independent component random fields. To investigate the impact of concrete's spatial variability on structural response and failure modes, the failure analysis of a 115-m-tall chimney was conducted. The results indicate that the composite random field approach proves to be a valuable method for incorporating concrete's spatial variability at different scales. The spatial variability of concrete exerts a substantial influence on the potential positions where severe compressive damage might occur. Additionally, the failure modes are also affected by the spatial variability of concrete. When taking into account the spatial variability of concrete, an extra collapse mode emerges, aligning more closely with the chimney's actual collapse mode during an earthquake. Furthermore, the spatial variability of concrete also moderately impacts the variability of the base shear force and the maximum inter-section drift angle. Notably, improper approaches to considering the spatial variability of concrete significantly impact the concrete's compressive damage and structural response.
Keywords: Composite random field; Spatial variability; Hierarchical structure; Failure modes.Fig. 1. Four hierarchies of concrete in RC structure
Fig. 2. Samples of random field
Fig. 3. Correlation coefficient function
Fig. 4. Generated complete compressive stress-strain curves
Fig. 5. Dimensions of the Tüpras chimney
Fig. 6. Kocaeli earthquake ground acceleration
Fig. 7. Finite element model of chimney
Fig. 8. First four modes and periods of chimney
Fig. 9. Random field samples of compressive strength
Fig. 10. Typical compressive damage clouds in set-1
Fig. 11. Complete compressive stress-strain curves of concrete
Fig. 12. Typical compressive damage clouds in set-2
Fig. 13. Typical compressive damage clouds in set-3
Fig. 14. Failure modes of chimney
Fig. 15. Maximum inter-section drift angles along NS directions
Fig. 2. Mean and standard deviation curves of the base shear force
作者信息 | Authors
南京工业大学 (Nanjing Tech University) 土木工程学院
广东工业大学 (Guangdong University of Technology) 土木与交通工程学院
南京工业大学 (Nanjing Tech University) 土木工程学院
宋玉鹏 Yu-Peng Song, 通讯作者 (Corresp.)南京工业大学 (Nanjing Tech University) 土木工程学院Email: songyupeng@njtech.edu.cn
律梦泽 M.Z. Lyu | 编辑 (Ed)
P.D. Spanos | 审校 (Rev)
陈建兵 J.B. Chen | 审校 (Rev)
彭勇波 Y.B. Peng | 审校 (Rev)
