Low-cycle fatigue testing and microstructure of high strength-ductility structural steel materials  

作　　者：Yongtao Bai Qingyu Gong Xuhong Zhou Nazim Babacan Shaoyu Guan 

机构地区：[1]School of Civil Engineering,Chongqing University,Chongqing 400045,China [2]Department of Mechanical Engineering,Sivas University of Science and Technology,Sivas 58140,Turkey [3]Department of Civil Engineering,Xi’an Jiaotong University,Xi’an 710049,China

出　　处：《Low-carbon Materials and Green Construction》2024年第1期492-503,共12页低碳材料与绿色建造(英文)

基　　金：supported by the National Key R&D Program of China under Grant No.2022YFB2602700;the National Natural Science Fund for Excellent Young Scientists Fund Program,the Fundamental Research Funds for the Central Universities(Grant No.2022CDJKYJH052);the Support Plan for Returned Overseas Scholars of Chongqing(cx2020022).

摘　　要：The well-known tradeoff between strength and ductility is a key issue in the large-scale engineering application of steel materials to resist fatigue due to earthquakes and other vibrational excitations.The steel production industry provides a vast range of technologies to achieve the desired performances.Through experimental research,it was found that FeCrNi-based high-ductility steel(HD-S)can demonstrate remarkable hysteresis behavior due to extensive deformation capacity of strain-hardening until the ultimate fracture,compared to industrially manufactured high-strength steel(HS-S)with the level of 1 GPa in yield strength.The balance between strength and ductility can be realized by slightly adding the percentage of Ni by 5%to achieve a ductile hysteresis behavior.Moreover,the HD-S specimens exhibit greater resistance to low-cycle fatigue with large plastic amplitude.By developing a new damage evolution law based on instantaneous damage differential during nonstationary fatigue history,the fatigue life of materials is extended into the inelastic hinges of flexural beams/origami components.The proposed approach enables the fatigue design of steel structural components with desirable disaster-prevention capacities for complex steel structures.强度和延性之间的权衡是钢结构材料在大规模工程应用中抵抗地震、疲劳及其它振动激励损伤的关键问题。通过试验研究发现,与屈服强度为1GPa级别工业生产的高强度钢(HS-S)相比,FeCrNi基高延性钢(HD-S)由于其应变硬化直至最终断裂的广泛变形能力,可以在疲劳过程中表现出显著的耗能特性。强度和延性之间的平衡可以通过添加约5%的Ni来实现,以获得延性伸长率和滞回性能。此外,HD-S试件能够更好地抵抗大塑性常幅下的低周疲劳破坏。基于疲劳过程中的瞬时损伤驱动变量,本文提出了一种新的损伤演化定律,将材料的疲劳寿命扩展到宏观弯曲梁、折纸构件的非弹性铰链中。本文提出的方法能够对具有理想防灾消能能力的钢结构构件进行疲劳建模与分析,以应用于钢结构极端建造中的疲劳设计。

关 键 词：Strength-ductility tradeoff Low-carbon steels High-performance steels Low-cycle fatigue MICROSTRUCTURE Lumped damage mechanics 

分 类 号：TG1[金属学及工艺—金属学]