摘要
为实现高强度结构钢材拉压大应变循环加载试验,避免受压失稳,采用了标距与直径比为1.13的特小标距试件。有限元分析结果表明,在此标距范围内,钢材屈服后应力、应变仍是均匀的。标准尺寸试件与特小标距试件的单调拉伸试验结果对比表明,为去除大应变范围内试件面积变化影响而采用真实应力-真实应变表达钢材力学行为是必要和有效的。针对屈服强度达到510MPa的国产高强度结构钢材,采用了循环拉伸、等幅升幅、等幅降幅和等幅交替4种不同的循环加载制度,使最大循环应变幅达到了±10%。试验获得了大应变范围内钢材的应力-应变关系及滞回特性,结果显示,大应变范围内循环加载时钢材的应力强化将有显著趋缓现象,与常用的双折线模型有显著不同。
In order to realize the cyclic loading tests on coupon specimen of high strength structural steel with large inelastic strains, and avoid buckling, the small gage coupon specimen with length-to-diameter ratio of 1.13 was adopted. Finite element analysis shows that the stress and strain within the gage length can keep uniform after yielding. For elimination of the effect of area change caused by very large strain, it is proved necessary and valid to express the stress-strain curve in true stress and true strain by the comparison of the monotonic tensile tests with standard coupon and small gage coupon specimens. A total of four different loading protocols, including cyclic tensile, cyclic ascending, cyclic descending and cyclic alternating, with maximum strain amplitude up to ± 10%, were adopted for the homemade high-strength structural steel with yield strengh of 510MPa. The obtained hysteretic stress- strain curves show that the stress hardening is mitigated, and the feature is obviously different from the commonly used bi-linear model.
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2014年第2期89-94,共6页
Journal of Building Structures
基金
科技部国家重点实验室基础研究项目(SLDRCE08-A-04)
国家自然科学基金重点项目(51038008)
关键词
高强度钢材
大应变
循环加载试验
滞回性能
high strength steel
large inelastic strains
cyclic loading test
hysteretic behavior
