《钢结构安装》课件-1.2.2 钢屋架节点设计

1.2.2钢屋架的节点设计

Jointdesignofsteelrooftruss第一：钢屋架节点的设计步骤First:thedesignstepsofsteelrooftrussjoints第二：弦杆拼接节点Second:chordsplicingnodes第三：支座节点Third:supportnodes钢结构的节点随结构形式的不同而不同。本节仅对普通钢屋架的节点计算方法及构造作一些简单的介绍。Thejointsofthesteelstructurevarywiththedifferentformsofthestructure.Thissectiononlygivessomebriefintroductiontothejointcalculationmethodandstructureofordinarysteelrooftrusses.

一、钢屋架节点的设计步骤

First:thedesignstepsofsteelrooftrussjoints

（1）根据腹杆截面和内力确定连接焊缝的焊脚尺寸和长度；Determinethesizeandlengthoftheweldjointsconnectingtheweldaccordingtothestudsectionandinternalforces（2）根据焊缝的长度和施工的误差确定节点板的形状和尺寸；Determinetheshapeandsizeofthegussetplateaccordingtothelengthoftheweldandtheerrorofconstruction（3）结合屋架施工图绘制进行。Combinedwiththedrawingofrooftrussconstructiondrawings.二、弦杆拼接节点

Second:chordsplicingnodes

弦杆拼接节点Chordsplicingnodes工地拼接

Sitesplicing工厂拼接Factorysplicing（1）工厂拼接：为了型钢接长而设的杆件接头，拼接点常设于内力较小的节间内。Factorysplicing:memberjointssetupforsectionsteeljoints,andthesplicingpointsarefixedintheinternodeswithlessinternalforce（2）工地拼接：由于运输条件限制而设的安装接头，拼接点通常设在屋脊节点和下弦跨中节点处。Sitesplicing:Duetotherestrictionsoftransportationconditions,thesplicingpointisusuallylocatedattheridgenodeandthelowerchordspanmiddlenode.屋脊节点Roofnodes下弦跨中节点Lowerchordspanmiddlenode大家可以看下图中的上图就是钢屋架的上弦拼接节点，设在屋脊处；再看图中的下图是下弦拼接节点，一般设置在跨中节点处。Youcanseethattheabovepictureinthefigurebelowisthewindingsplicingnodeofthesteelrooftruss,whichislocatedattheridge;Lookingatthefigurebelow,thefollowingfigureisthelowerchordsplicingnode,whichisgenerallysetatthecross-middlenode.弦杆采用拼接角钢拼接。拼接角钢采用的规格一般与弦杆相同(当弦杆截面改变时，与较小截面弦杆相同)。在施工中，为了使拼接角钢能贴紧被连接的弦杆和便于施焊，需要截去拼接角钢的外棱角，并把竖向肢切去mm(其中t是拼接角钢肢厚，h是角焊缝焊脚尺寸，5mm是为避开弦杆角钢肢尖的圆角而考虑的切割余量)。拼接时为正确定位和便于施焊，须设置临时性的安装螺栓。Thechordissplicedwithsplicedanglesteel.Thespecificationsusedforsplicinganglesteelaregenerallythesameasthechord(thesameasthesmallersectionchordwhenthechordsectionchanges).Inconstruction,inordertomakethesplicinganglesteelfittheconnectedchordandfacilitatewelding,itisnecessarytocutofftheouteredgesandcornersofthesplicedanglesteelandcutofftheverticallimbmm(wheretisthesplicinganglesteellimbthickness,histhefilletweldfootsize,5mmisacuttingallowancetoavoidtheroundedcornersofthesteeltipofthechordangle).Inordertocorrectlypositionandfacilitateweldingduringsplicing,temporarymountingboltsmustbeinstalled

三、支座节点

Third:supportnodes

加劲肋Stiffeners节点板Gussetplates锚栓Anchors支座底板Supportbaseplate支座节点Supportnode加劲肋Stiffeners加劲肋的作用是加强底板的刚度，以便较为均匀地传递支座反力并提高节点板的侧向刚度。加劲肋应设在支座节点的中心处，加劲肋高度由节点板尺寸确定，加劲肋厚度取与节点板相同。肋板底端应切角以避免3条互相垂直的角焊缝交于一点。Thefunctionofstiffenersistostrengthenthestiffnessofthebaseplateinordertotransmitthesupportreactionforcemoreevenlyandimprovethelateralstiffnessofthegussetplate.Thestiffenershouldbelocatedinthecenterofthesupportnode,theheightofthestiffenerisdeterminedbythesizeofthegussetplate,andthestiffenerthicknessshouldbethesameasthegussetplate.Thebottomendoftheribplateshouldbecuttoavoid3filletweldsperpendiculartoeachotheratonepoint.2.锚栓Anchors锚栓锚栓预埋于柱中，其直径一般取20～25mm。为了便于安装屋架时能够调整位置，底板上的锚栓孔直径应为锚栓直径的2～2.5倍。屋架安装完毕后，在锚栓上套上垫圈，并与底板焊牢以固定屋架，垫圈的孔径比锚栓直径大1～2mm。Theanchorisembeddedinthecolumn,anditsdiameterisgenerally20~25mm。Inordertofacilitatethepositiontobeadjustedwheninstallingrooftrusses,thediameteroftheanchorholeonthebottomplateshouldbe2~2.5timesoftheanchordiameter。Aftertherooftrussisinstalled,putawasherontheanchor,andwelditfirmlywiththebottomplatetofixtherooftruss,andtheholediameterofthewasheris1~2mmlargerthanthediameteroftheanchor.3.支座节点的传力路径Theforcetransmissionpathofthesupportnode屋架杆件的内力通过连接焊缝传给节点板，然后经节点板和加