山东建筑大学学报
山東建築大學學報
산동건축대학학보
JOURNAL OF SHANDONG JIANZHU UNIVERSITY
2015年
4期
307-317
,共11页
傅传国%刘玮%孔唯一%王玉镯
傅傳國%劉瑋%孔唯一%王玉鐲
부전국%류위%공유일%왕옥탁
钢筋混凝土梁%火灾%温度场分析
鋼觔混凝土樑%火災%溫度場分析
강근혼응토량%화재%온도장분석
reinforced concrete beam%fire%temperature field analysis
文章基于 ISO834标准升降温全曲线,运用 ABAQUS 非线性有限元分析软件,以钢筋混凝土矩形截面梁为例,进行了单面、三面及四面受火工况下的梁截面温度场分析,得出了梁截面不同观测点的温度随标准升降温全曲线的变化规律。结果表明:由于混凝土的热惰性,越靠近受火面温度变化梯度越显著,除直接受火的截面边界之外,截面内部的升温出现不同程度的滞后现象,离受火面距离越远,滞后时间越长;钢筋混凝土梁经历升降温全过程后,梁截面各点经历的升温峰值温度不同,达到升温温度峰值的时间也不同,越远离受火面越滞后;在受火面停止升温进入降温阶段时,截面内部可能还处在升温阶段,形成了钢筋混凝土梁在受火面升温时其外部受火面温度高于截面内部温度,而在受火面停止升温进入降温段时,截面内部温度存在高于外部温度的情况,此现象在分析受火灾作用钢筋混凝土梁的承载性能时应加以考虑。
文章基于 ISO834標準升降溫全麯線,運用 ABAQUS 非線性有限元分析軟件,以鋼觔混凝土矩形截麵樑為例,進行瞭單麵、三麵及四麵受火工況下的樑截麵溫度場分析,得齣瞭樑截麵不同觀測點的溫度隨標準升降溫全麯線的變化規律。結果錶明:由于混凝土的熱惰性,越靠近受火麵溫度變化梯度越顯著,除直接受火的截麵邊界之外,截麵內部的升溫齣現不同程度的滯後現象,離受火麵距離越遠,滯後時間越長;鋼觔混凝土樑經歷升降溫全過程後,樑截麵各點經歷的升溫峰值溫度不同,達到升溫溫度峰值的時間也不同,越遠離受火麵越滯後;在受火麵停止升溫進入降溫階段時,截麵內部可能還處在升溫階段,形成瞭鋼觔混凝土樑在受火麵升溫時其外部受火麵溫度高于截麵內部溫度,而在受火麵停止升溫進入降溫段時,截麵內部溫度存在高于外部溫度的情況,此現象在分析受火災作用鋼觔混凝土樑的承載性能時應加以攷慮。
문장기우 ISO834표준승강온전곡선,운용 ABAQUS 비선성유한원분석연건,이강근혼응토구형절면량위례,진행료단면、삼면급사면수화공황하적량절면온도장분석,득출료량절면불동관측점적온도수표준승강온전곡선적변화규률。결과표명:유우혼응토적열타성,월고근수화면온도변화제도월현저,제직접수화적절면변계지외,절면내부적승온출현불동정도적체후현상,리수화면거리월원,체후시간월장;강근혼응토량경력승강온전과정후,량절면각점경력적승온봉치온도불동,체도승온온도봉치적시간야불동,월원리수화면월체후;재수화면정지승온진입강온계단시,절면내부가능환처재승온계단,형성료강근혼응토량재수화면승온시기외부수화면온도고우절면내부온도,이재수화면정지승온진입강온단시,절면내부온도존재고우외부온도적정황,차현상재분석수화재작용강근혼응토량적승재성능시응가이고필。
The paper studies the change rule of temperature field of reinforced concrete structures in the process of rise and cooling temperature under high temperature which is of great significance to understand its when subjected to fire resistance. In this paper,based on standard ISO834 heating and cooling curve,using the nonlinear finite element analysis software ABAQUS,with reinforced concrete rectangular section beam as an example,the beam cross section temperature field analysis on single side,three sides and four sides fire conditions has been carried out,and the whole temperature to time curve of the different observation points in beam section is obtained. The analysis results show that due to the thermal inertia of concrete,more close to the fire side of beam section,the temperature gradient is more significant. In addition to direct fire section boundary,the cross section of internal temperature appears different degree of hysteresis,the farther from the fire surface distance,the longer the time lag. After Heating and cooling process,in the beam section,the peak temperature of warming experience are different at various observation points and the time to reach the peak temperature are different too,and the more far away from the fire surface,the more lagging. When beam surface stopping heating and into the cooling stage,Cross section internal observation point may still in the phase of heating,so when beam external surface warming the internal temperature of the surface is higher than the external surface,and when beam surface stopping heating and into the cooling stage,the temperature of the internal cross section are higher than that of beam surface.