Cumulative Deformation Capacity of Structural Steel Subjected to Extremely Large Amplitude Strain Histories
Cumulative Deformation Capacity of Structural Steel Subjected to Extremely Large Amplitude Strain Histories
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DOI：
10.1016/j.jobe.2021.102649
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发表时间：
2021-05
影响因子：
6.4
通讯作者：
Yuying Jiao;S. Yamada
中科院分区：
文献类型：
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作者：
Yuying Jiao;S. Yamada
本文研究了结构钢在大应变下的变形行为。当结构经历强烈地震时，断裂位置处的应变幅度可能相当大，并且材料在几个加载循环后断裂。Manson-Coffin关系通常用于预测循环载荷下金属的失效。然而，传统的Manson-Coffin关系并不一定适用于某些材料在非常大的应变幅。很少有相关的实验，很大程度上是因为它是很难再现结构钢行为下的大幅循环应变在实验室中由于屈曲。本文对71个结构钢试件在不同的轴向应变循环加载和单调拉伸下进行了加载直至断裂的试验。通过对滞回曲线的分析，得到了累积应变与骨架部分的关系。由于试验装置的限制，最大压缩应变幅为6%，这仍然不足以研究结构钢在强震下的材料性能。因此，数值模拟的单钢元件进行循环应变，以补充材料的行为下，非常大的恒定应变幅。结合试验和分析结果，通过应变-寿命曲线评价了结构钢在超大应变幅下的累积变形能力。在本研究的最后部分中，借由先前研究的实验结果来验证所提出的应变-寿命曲线。
This study investigated deformation behavior of structural steel subjected to large strain. When structures experience powerful earthquakes, strain amplitudes at the fracture locations can be quite large, and the material fractures after few loading cycles. The Manson-Coffin relationship is commonly used to predict failure of metals subjected to cyclic loadings. However, the traditional Manson–Coffin relationship does not necessarily hold for some materials under extremely large strain amplitude. There are few relevant experiments, largely because it is difficult to reproduce structural steel behavior under large amplitude cyclic stains in the laboratory due to buckling. In this study, 71 steel plate specimens of structural steel were loaded until fracture under diverse cyclic axial strain loadings and monotonic tension. The relationship between cumulative strain and its skeleton portion was obtained based on the analysis of the hysteresis loops. Due to the limitation of test setup, the largest compression strain amplitude is 6%, which is still not sufficient to study the material behavior of structural steel under severe earthquakes. Therefore, numerical simulations of single steel elements subjected to cyclic strain were conducted to complement the material behavior under extremely large constant strain amplitudes. The cumulative deformation capacity of structural steel subjected to extremely large strain amplitudes was evaluated through a strain-life curve with the experimental and analytical results. In the final part of this study, experimental results from former research were introduced to validate the proposed strain-life curve.