摘要
采用恒载升温试验方法,对国内10个厂家生产的Q345钢试件在600℃下进行40次有效试验,得到每批次试件在不同荷载下变形随时间的变化曲线。把试件的总变形分离为初始荷载变形、膨胀变形以及温度-荷载耦合变形3部分,并将变形曲线分成3个区间,根据变形速率的变化特点,以某一荷载下变形速率加速变大作为试件屈服的临界荷载水平,得到各批次试件在600℃的临界荷载水平为0.30~0.40。并提出保证建筑安全的前提是火灾中温度和荷载的耦合变形不超过安全值。
An experimental study on Q345 steel coming from 10 factories at 600 ℃ degree were carried out with transient tests.A series of deformation curves varing with time are obtained.The total deformation of steel was defined as sum of pre-heating deformation,thermal expansion deformation and force-temperature coupled deformation.According the characteristic of the deformation,the load value is defined as the critical load level when the speed of deform become larger.The result shows the critical load level value is between 0.30 to 0.40 at 600 ℃.In the end,a suggestion that the load-temperature coupled deformation is not allowed to excess the safety value in the fire was put forward.
出处
《钢结构》
2009年第11期84-88,共5页
Steel Construction
