英语翻译Composite structures are nowadays used,principally in hi

英语翻译
Composite structures are nowadays used,principally in high-rise buildings,due to its high load-bearing capacity andseismic and fire resistance.There are already several research works on thefire behaviour of composite steel and concrete columns with restrained thermalelongation,mainly of numerical nature,but a few were carried out on compositecolumns made of totally encased steel sections.This paper presents the resultsof an experimental research carried out in this last type of columns subjectedto fire.Several parameters that might have influence on its behaviour weretested,such as the initial applied load level,the stiffness of thesurrounding structure (i.e.axial and rotational restraining tothermal elongation) and the dimensions of the cross-section that resulted indifferent slenderness values of the columns tested.The tabulated data of EN1994-1-2 (2005),for these type of columns,showed to be very conservative andon the safe side,when compared with those resulted from the experimental testsof the present investigation,because the ones of this code may have an empiricbase and resulted from columns tested without thermal restraining.The loadlevel and concrete cover showed to have a big influence on the critical time ofthe columns.Increasing the first reduced while increasing the second increasedthe critical time of the tested columns.

目前采用复合结构,主要是在高层建筑中,由于其高承载能力和地震、防火.已经有对抑制润肤延长复合钢和混凝土柱火灾特性的研究工作,主要的数值性质,但很少对复合柱型钢截面进行全.本文介绍了结果的实验研究进行了这最后一种类型的柱的抗火.几个参数,可能对其行为进行影响,如初始荷载水平,周围结构的刚度（即轴向和转动约束的热伸长）和横截面的柱,导致测试冷漠的长细值尺寸.表列数据（2005）,en1994-1-2这些类型的列,表明是非常保守和安全方面,相比与那些导致从实验结果,目前的调查,因为这个代码的人可能有经验基础,导致柱无热抑制试验.水平荷载下混凝土覆盖显示在关键时刻的列大的影响.增加先减小而增加二增加临界时间的测试列.