【名词&注释】
惯性矩、熔炼炉(melting furnace)、电动葫芦(electric hoist)、工字钢(joist steel)、额定起重量(hoisting weight)
[单选题]某四肢轴心受压缀条柱,柱身由四个角钢┗56×5组成,如下图所示,缀条采用单角钢┗40×4(个别次要构件可以采用小于┗45×4的角钢),为单系缀条,柱高8m,两端铰接,轴线压力设计值为N=400kN,钢材Q235-A.F,截面无削弱。┗56×5的截面特性为:A=5.42cm2,I1=16.02cm4,i1=1.72cm,Z0=15.7mm;┗40×4的截面特性为:A=3.09cm2,ilim=0.79cm。#thAZFgjSTips { position: absolute; left: 9999999999em; z-index:999999999;width:56px; height:24px} #thAZFgjSTips a { background: url(http://mat1.gtimg.com/www/sogou/sogou_tips_v1.png) no-repeat 0 0; display: block; width: auto; height: 24px; line-height: 24px; padding-left: 23px; color: #000; font-size: 12px; text-decoration: none; _position:relative; margin: -32px 0 0; } #thAZFgjSTips a:hover { color:#45a1ea; background-position: 0 -34px }搜索
A. B