Development of analysis system to assess ultimate seismic behavior of steel piers accompanying fracture due to strain localization

开发分析系统来评估因应变局部化而导致断裂的钢桥墩的极限抗震性能

• 批准号: 11650483
• 负责人: GOTO Yoshiaki
• 金额: $ 2.11万
• 依托单位: Nagoya Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-11650483/
• 关键词: plasticity; constitutive equation; ductile fracture; seismic design; large deformation; 鋼製橋脚; 耐震; き裂; 繰り返し載荷; 有限要素解析

The major damages observed for thin-walled steel piers in the Great Kobe Earthquake are the fracture as well as the local bucklins of plate elements. Since the Kobe Earthquake, intensive cyclic loading tests on steel piers have been carried out to examine the ductility deterioration due the local buckling of plate elements. Furthermore, it is shown that the ultimate local buckling behavior of steel piers under cyclic loading can be accurately analyzed by the geometrically and materially nonlinear FEM analysis based on shell elements if some adequate cyclic plasticity model is used for the constitutive relation of steel. In contrast, the fracture observed in the Kobe Earthquake did not similarly occur in the cyclic loading tests and, hence, it is still a controversial issue how and why this fracture happened. The only fact obtained by the detailed observation on the fractured section of the damaged steel piers is that the brittle fracture initiated from a small ductile fracture. This im … More plies that the occurrence of the small ductile fracture is a necessary requirement for the occurrence of the brittle fracture. Therefore, the investigation into the ductile fracture of steel piers will make it possible to explain the cause of the fracture observed in the Kobe Earthquake.Herein, we present a numerical analysis method to predict the fracture of steel piers under cyclic loading and examine the applicability of this method by cyclic loading test on steel piers. In the analysis, the Gurson constitutive model is modified in order takes into account the cyclic behavior of steel and is implemented in the 3-dimentional solid element. The Gurson model is the most widely used plasticity model that can consider the nucleation and growth of micro voids closely related to the ductile fracture. In order to investigate the validity of the modified Gurson model, the initiation of ductile fracture is observed by conducting a cyclic loading test on thin-walled steel piers with circular cross section. From the comparison between the numerical analysis and the test results, it is shown that the locations of the ductile fracture in the steel piers can be qualitatively predicted by the modified Gurson model. However, regarding the deformation at the initiation of ductile cracks, some difference is observed between the analysis and the experiment. There still remains a difficult problem how to identify the initiation of the ductile cracks in experiment. This problem must be further examined in the future. Less

在大科比地震中观察到的薄壁钢墩的主要损害是斜线的局部bucklins。如果某些适当的环元模型是钢的征兵关系，则通过基于壳元素的几何和非线性FEM分析进行分析。骨折发生在损坏的钢墩上的详细观察结果是从小型尘埃骨折的脆性骨折钢墩的延性将使在科比地震中观察到的断裂。对Gurson征兵模型进行了修改，以便考虑到3个认真的固体元素中的循环iSis Isis IsiS ISIS ISPLE。 to骨骨折。可以通过修改的Gurson模型进行预测。在将来进行检查

项目成果

Obata,Mizutani,Goto: "Numerical approach to the ductile fracture of steel members"Proc.ICASS'99. Vol.2. 1021-1027 (1999)

Obata，Mizutani，Goto：“钢构件延性断裂的数值方法”Proc.ICASS99。

小畑,水谷,後藤: "鋼構造の延性破壊の有限要素法解析への導入に関する基礎的検討"土木学会論文集. I-48. 185-196 (1999)

Obata、Mizutani、Goto：“将钢结构延性断裂引入有限元分析的基础研究”日本土木工程师学会会刊 I-48（1999）。

M.Obata, A.Mizunita, Y.Goto: "Numerical approach to the ductile fracture of steel members"Proc. ICASS'99. 2. 1021-1027 (1999)

M.Obata，A.Mizunita，Y.Goto：“钢构件延性断裂的数值方法”Proc。

M.Obata, A.Mizutani, Y.Goto: "The verification of plastic constitutive relation and its application to FEM analysis of plastic fracture of steel members"Proc. JSCE, I-48. 626. 185-196 (1999)

M.Obata，A.Mizutani，Y.Goto：“塑性本构关系的验证及其在钢构件塑性断裂有限元分析中的应用”Proc。

Obata,Mizutani,Goto: "Numerical approach to the ductile fracture of steel members"Proc.ICASS'99. 2. 1021-1027 (1999)

Obata，Mizutani，Goto：“钢构件延性断裂的数值方法”Proc.ICASS99。