功能材料
功能材料
공능재료
JOURNAL OF FUNCTIONAL MATERIALS
2014年
15期
15124-15128
,共5页
高应变低周疲劳%抗震钢筋%细晶%余热处理%循环韧度
高應變低週疲勞%抗震鋼觔%細晶%餘熱處理%循環韌度
고응변저주피로%항진강근%세정%여열처리%순배인도
high strain and low cycle fatigue%seismic rebar%grain refinement%tempcore%cyclic toughness
基于钢筋混凝土中钢筋在地震交变载荷下的失效模型,采用恒应变控制方式,室温下对细晶化和余热处理两种生产工艺得到的400 MPa 级抗震钢筋的高应变低周疲劳性能进行了研究。疲劳寿命数据用双参数威布尔统计方程处理后采用 Coffin-Manson 和Hollomon 公式拟合。为了计算地震载荷下钢筋的能量吸收率,建立一个新的预测模型并命名为循环韧度。结果表明,相对于余热处理钢筋,细晶钢筋具有更高的循环韧度、低周疲劳寿命,以及疲劳过渡寿命。余热处理钢筋在±1%应变幅以上加速循环软化,这是由于其表层回火马氏体中二次裂纹在循环载荷下萌生并快速扩展造成的。细晶钢筋循环塑性应变均匀,裂纹开裂几率小,具有较好的高应变低周疲劳性能。
基于鋼觔混凝土中鋼觔在地震交變載荷下的失效模型,採用恆應變控製方式,室溫下對細晶化和餘熱處理兩種生產工藝得到的400 MPa 級抗震鋼觔的高應變低週疲勞性能進行瞭研究。疲勞壽命數據用雙參數威佈爾統計方程處理後採用 Coffin-Manson 和Hollomon 公式擬閤。為瞭計算地震載荷下鋼觔的能量吸收率,建立一箇新的預測模型併命名為循環韌度。結果錶明,相對于餘熱處理鋼觔,細晶鋼觔具有更高的循環韌度、低週疲勞壽命,以及疲勞過渡壽命。餘熱處理鋼觔在±1%應變幅以上加速循環軟化,這是由于其錶層迴火馬氏體中二次裂紋在循環載荷下萌生併快速擴展造成的。細晶鋼觔循環塑性應變均勻,裂紋開裂幾率小,具有較好的高應變低週疲勞性能。
기우강근혼응토중강근재지진교변재하하적실효모형,채용항응변공제방식,실온하대세정화화여열처리량충생산공예득도적400 MPa 급항진강근적고응변저주피로성능진행료연구。피로수명수거용쌍삼수위포이통계방정처리후채용 Coffin-Manson 화Hollomon 공식의합。위료계산지진재하하강근적능량흡수솔,건립일개신적예측모형병명명위순배인도。결과표명,상대우여열처리강근,세정강근구유경고적순배인도、저주피로수명,이급피로과도수명。여열처리강근재±1%응변폭이상가속순배연화,저시유우기표층회화마씨체중이차렬문재순배재하하맹생병쾌속확전조성적。세정강근순배소성응변균균,렬문개렬궤솔소,구유교호적고응변저주피로성능。
Based on the failure model of rebars in reinforced concrete structures under earthquake loading,under total strain controlled,high strain and low cycle fatigue(HSLCF)behaviors of 400 MPa grade rebars produced by the technology of grain refinement and tempcore were tested at room temperature.After double-parameter weibull equation processed,the fatigue data were fitting by Coffin-Manson and Hollomon relationship.In order to calculate the rate of energy absorption under seismic loading,a new model named “cyclic toughness”were proposed.It was concluded that as compared with grain refinement rebar,tempcore rebar have higher cyclic toughness,low cycle fatigue life and fatigue transition life.Tempcore rebar accelerate its cyclic softening under strain amplitude of 1%,the reason was that the second crack propagated quickly in the surface of self-temper martensite.For grain refine rebars,cyclic plastic strain was uniform,and crack initiated probability was small, so that it have better high strain and low cycle fatigue performance.