振动与冲击
振動與遲擊
진동여충격
JOURNAL OF VIBRATION AND SHOCK
2014年
20期
12-15,25
,共5页
声发射%b值%加载速率%损伤评估
聲髮射%b值%加載速率%損傷評估
성발사%b치%가재속솔%손상평고
acoustic emission%b-value%loading rate%damage evaluation
利用声发射（Acoustic Emission，AE）技术分析动、静态加载下钢筋混凝土柱的断裂、损伤特性。用40 mm/s，0．1 mm/s两加载速率分别进行钢筋混凝土柱多维循环加载试验。据AE的b值理论捕捉宏观裂纹开始拓展时刻荷载状况，提出用定义宏观开裂发生荷载与极限荷载之比评估钢筋混凝土结构损伤；并对比分析动、静态加载实验中钢筋混凝土柱宏观裂纹初始荷载状况与损伤增长速率。结果表明，利用b值理论即声发射信号幅值分布变化，能捕捉到钢筋混凝土柱裂纹宏观拓展时刻；与静态加载相比动态加载时宏观裂纹的形成所需荷载更小，动态加载更易导致宏观裂纹形成；AE事件累计时间参数能清晰反映钢筋混凝土柱的损伤增长速率，且加载速率高的构件损伤速率高于加载速率低的构件，高加载速率更易导致、加剧结构损伤。
利用聲髮射（Acoustic Emission，AE）技術分析動、靜態加載下鋼觔混凝土柱的斷裂、損傷特性。用40 mm/s，0．1 mm/s兩加載速率分彆進行鋼觔混凝土柱多維循環加載試驗。據AE的b值理論捕捉宏觀裂紋開始拓展時刻荷載狀況，提齣用定義宏觀開裂髮生荷載與極限荷載之比評估鋼觔混凝土結構損傷；併對比分析動、靜態加載實驗中鋼觔混凝土柱宏觀裂紋初始荷載狀況與損傷增長速率。結果錶明，利用b值理論即聲髮射信號幅值分佈變化，能捕捉到鋼觔混凝土柱裂紋宏觀拓展時刻；與靜態加載相比動態加載時宏觀裂紋的形成所需荷載更小，動態加載更易導緻宏觀裂紋形成；AE事件纍計時間參數能清晰反映鋼觔混凝土柱的損傷增長速率，且加載速率高的構件損傷速率高于加載速率低的構件，高加載速率更易導緻、加劇結構損傷。
이용성발사（Acoustic Emission，AE）기술분석동、정태가재하강근혼응토주적단렬、손상특성。용40 mm/s，0．1 mm/s량가재속솔분별진행강근혼응토주다유순배가재시험。거AE적b치이론포착굉관렬문개시탁전시각하재상황，제출용정의굉관개렬발생하재여겁한하재지비평고강근혼응토결구손상；병대비분석동、정태가재실험중강근혼응토주굉관렬문초시하재상황여손상증장속솔。결과표명，이용b치이론즉성발사신호폭치분포변화，능포착도강근혼응토주렬문굉관탁전시각；여정태가재상비동태가재시굉관렬문적형성소수하재경소，동태가재경역도치굉관렬문형성；AE사건루계시간삼수능청석반영강근혼응토주적손상증장속솔，차가재속솔고적구건손상속솔고우가재속솔저적구건，고가재속솔경역도치、가극결구손상。
The focus of the paper is to analyse the fracture and damage characteristics of reinforced concrete (RC) column subjected to dynamic and static loading based on acoustic emission (AE )technique.The multi-dimensional dynamic/static loading tests of RC columns were conducted with the loading rate of 40mm/s and 0.1 mm/s respectively. By b-value analysis,the moment of macro-crack opening was acquired,and based on which,the ratio of macro-crack opening load to maximum load was proposed to evaluate the damage condition.In addition,the load condition and damage accumulation rate of RC column subjected to both dynamic and static loading were analyzed.The results show that:according to the distribution of AE amplitude,which also can be seen as b-value,the moment of macro-crack opening in RC column can be captured.The macro-crack opening of RC column subjected to dynamic loading happens under smaller external load compared with the one subjected to pure static loading.Dynamic loading is more likely to lead the formation of macro-crack.The time parameter of AE event accumulation can clearly reflect the damage accumulation rate of RC column.Moreover,the damage accumulation rate in high loading rate specimen is larger than the one in ordinary loading rate specimen.And the high loading rate is more easy to make and aggravate structural damage.
