輕鋼結(jié)構(gòu)檁條設(shè)計(jì)問題探討.doc

1、輕鋼結(jié)構(gòu)檁條設(shè)計(jì)問題探討摘要：PKPMSTS軟件設(shè)計(jì)中檁條的強(qiáng)度及穩(wěn)定計(jì)算提出一些應(yīng)用思路。關(guān)鍵詞:PKPM-STS； 屋面檁條; 墻面檁條 一、屋面檁條1。簡支檁條計(jì)算通常選用C型檁條，開口朝向屋脊方向.如屋面為單層或雙層彩鋼板夾玻璃絲棉的維護(hù)材料,恒荷載通常取0。150.2KN/ .其它材料跟據(jù)實(shí)際重量核算。活荷載取荷載規(guī)范規(guī)定的屋面活荷載與當(dāng)?shù)匮┖奢d的較大值。積灰荷載與施工荷載根據(jù)實(shí)際情況確定。如果屋面板采用自攻螺釘與檁條固定,保證屋面板與檁條可靠連接,能阻止檁條上翼緣側(cè)向位移和扭轉(zhuǎn)，此時(shí)只需計(jì)算檁條強(qiáng)度,但這種板型因溫度變形能力和防水能力較差,現(xiàn)在較少采用。目前采用較多的是暗扣式板型，

2、這種連接方式在溫度變化較大時(shí)屋面板能產(chǎn)生滑動(dòng)，不宜將它假定為能阻止檁條上翼緣側(cè)向位移和扭轉(zhuǎn)，除了計(jì)算檁條強(qiáng)度,還需計(jì)算其穩(wěn)定性。屋面檁條計(jì)算和拉條的設(shè)置有關(guān)。根據(jù)門規(guī)，當(dāng)檁條跨度大于4m時(shí),宜在檁條間跨中設(shè)置拉條；跨度大于6m時(shí)宜在檁條跨度三分點(diǎn)處各設(shè)一道拉條,在屋脊處還應(yīng)設(shè)置斜拉條及撐桿。在恒載?；钶d及風(fēng)壓力作用下，檁條上翼緣受壓，拉條應(yīng)設(shè)置在檁條上翼緣1/3處。在風(fēng)吸力作用下使檁條下翼緣受壓，拉條不能保證檁條下翼緣的側(cè)向位移和扭轉(zhuǎn)，如果計(jì)算時(shí)要考慮拉條能約束檁條下翼緣,此時(shí)應(yīng)在檁條下翼緣1/3處同樣設(shè)置拉條，所以檁條設(shè)計(jì)最好用雙層拉條.2.連續(xù)檁條計(jì)算通常選用Z型檁條，開口朝向檐口方向。由

3、于Z型檁條可用搭接形式,故可把這樣的檁條假定成連續(xù)構(gòu)件。（1） 采用Z 型搭接連續(xù)檁條比簡支檁條內(nèi)力分布均勻，剛度大,可節(jié)省用鋼量。(2） 搭接連續(xù)檁條在支座處搭接區(qū)存在嵌套松弛現(xiàn)象,其剛度小于等截面連續(xù)單檁的剛度,因此在支座處有一定彎矩釋放，在跨中彎矩有一定的增大。(3) 連續(xù)檁條整體穩(wěn)定計(jì)算目前尚不完善，其整體穩(wěn)定可利用屋面蒙皮作用和拉條支撐系統(tǒng)解決.(4) 連續(xù)檁條支座處的彎矩大于跨中彎矩,搭接區(qū)承載能力按兩檁條的抗彎模量之和考慮是合理的，可以大大節(jié)省用鋼量。（5) 連續(xù)檁條的搭接長度不宜小于跨長的10 ,搭接長度按端跨和中間跨的彎矩分布情況分別考慮,以搭接端彎矩不大于跨中彎矩為條件來確

4、定搭接長度可使設(shè)計(jì)更為經(jīng)濟(jì)合理。(6） 用檁條兼作屋面縱向壓桿，當(dāng)單檁不能滿足承載力要求,可用雙檁條,此方法節(jié)省用鋼量。(7） 連續(xù)檁條與屋面梁的連接應(yīng)采用加檁托板螺栓連接方式以防檁條局部腹板壓屈和整體傾覆。當(dāng)檁條腹板高厚比較大時(shí)尚應(yīng)加設(shè)厚墊片以改進(jìn)其支座處的承載力.(8） 一般情況下，設(shè)計(jì)帶隅撐的檁條時(shí)，隅撐對(duì)檁條的有利作用與不利影響可考慮相互抵消,忽略不計(jì),以簡化設(shè)計(jì)二、墻面檁條1. 簡支墻梁計(jì)算通常選用C型檁條，開口朝向根據(jù)實(shí)際情況確定。一般墻梁開口朝上，但窗洞口下側(cè)檁條可讓檁條開口朝下布置以滿足固定窗框的需求。墻梁設(shè)計(jì)與屋面檁條類似，同樣要考慮墻板.拉條的約束作用。不同的是墻板有自承重

5、和非自承重兩種，要根據(jù)具體情況具體分析。另外。墻梁設(shè)計(jì)時(shí)根據(jù)構(gòu)造條件的不同要考慮雙彎矩板的影響。根據(jù)冷彎薄壁型鋼結(jié)構(gòu)技術(shù)規(guī)范8.3。1條及條文說明，兩側(cè)掛墻板的墻梁和一側(cè)掛墻板.另一側(cè)沒有可以阻止其扭轉(zhuǎn)變形的拉桿墻梁，可不計(jì)雙力矩的影響？（即可取B=0)，此時(shí)可僅進(jìn)行墻梁的強(qiáng)度計(jì)算。對(duì)于風(fēng)吸力作用下內(nèi)翼緣的穩(wěn)定性計(jì)算,與屋面檁條類似，墻板一般采用自攻螺釘與檁條固定,可認(rèn)為墻板能阻止墻梁外翼緣側(cè)向失穩(wěn)。拉條設(shè)置在墻梁內(nèi)側(cè)比增大檁條截面更經(jīng)濟(jì)。對(duì)于自承重墻板，可僅在內(nèi)側(cè)設(shè)置拉條.對(duì)于非自承重墻板，宜在墻梁內(nèi)外設(shè)雙側(cè)拉條，外側(cè)拉條可以作為墻板在自重作用下墻梁的豎向支撐點(diǎn)。在墻板頂部和窗戶下的墻梁處應(yīng)

6、同時(shí)設(shè)置斜拉條和直撐桿,將拉力傳至剛架柱或墻架柱,底部墻梁一般固定在墻垛或矮墻上,整體穩(wěn)定有保證，故底部墻梁處可不設(shè)置斜拉條和直撐桿。三、拉條的設(shè)置拉條雖小，作用不小。實(shí)際上有檁條系的壓型鋼板輕型變形和扭轉(zhuǎn)，減小檁條的計(jì)算長度，保證檁條的側(cè)向穩(wěn)定作用.拉條一般通過螺栓與檁條連接，拉條與屋面板的共同作用能有效地提高檁條的整體抗扭轉(zhuǎn)度和減少外部荷載引起的扭轉(zhuǎn)效應(yīng)。雖然在檁條下翼緣附近有無拉條對(duì)檁條的抗彎承載力有很大影響,但當(dāng)拉條強(qiáng)度滿足后，拉條的剛度對(duì)抗彎和壓彎承載力的影響可忽略。所以門規(guī)推薦拉條的最小直徑取10mm，去除車絲對(duì)截面的削弱及銹蝕等因素外是可行的，但應(yīng)注意：每一個(gè)坡面上的檁條是一個(gè)大

7、的串聯(lián)系統(tǒng)，因此檁條的受力是不均勻的，恒活載作用下離屋脊處越近的拉條內(nèi)力越大,而在風(fēng)吸力作用下正好相反。在檁條的設(shè)計(jì)中應(yīng)考慮多根檁條由拉條串聯(lián)后的內(nèi)力疊加。當(dāng)房屋坡度方向較大應(yīng)間隔一定數(shù)量的拉條設(shè)置一對(duì)斜拉條,以分段傳遞內(nèi)力.因拉條只能受拉，但拉條作為檁條的側(cè)向支撐點(diǎn)時(shí)，同時(shí)受拉和受壓,因此在檐口和屋脊應(yīng)布置斜拉條和撐桿，以形成幾何不變體系.撐桿按壓桿設(shè)計(jì)，不宜用圓鋼.Light steel purlin design problem discussed in this paper Pick to： PKPM - STS software in the design of purlin the

8、 strength and stability calculation of some applications. Keywords: PKPM STS； Roofing purline； The metope of purlin A, roof purlin 1。 The simply supported purlin is calculated Usually choose C purlin， ridge direction. Such as roofing for single or double colored powder glass cotton material to maint

9、ain, constant load usually take 0。15 0。2 KN / . Other materials according to the actual weight calculation。 Live load in load code for the rules of roof live load and the larger value of the local snow load。 Heavy load and construction load according to the actual situation。 If roof board with self-

10、tapping screws fixed and purlin， ensure roof panel and purlin connections， can prevent the purlin flange on the lateral displacement and torsion， just calculate purlin intensity at this time, but this kind of board type deformation due to temperature and waterproof ability is poorer， less used now。

11、Is currently using more dark buckle type plate type， the connection way in large temperature changes in the roof plate can produce sliding， unfavorable and it can prevent the purlin is assumed on the flange lateral displacement and torsion， in addition to the purlin strength calculation， still need

12、to calculate the stability。 個(gè)人收集整理,勿做商業(yè)用途個(gè)人收集整理,勿做商業(yè)用途Roofing purline calculation and brace is set. According to the rules, when the purlin span more than 4 m, appropriate is set in the purlin across brace； A time span is more than 6 m in span purlin three locations in each set a brace， also should

13、be set at roof of batter brace and poles。 At constant load. Under the action of live load and wind pressure, purlin flange compression and brace should be set on the purlin flange 1/3。 Under the wind suction under the action of the purlin flange compression and brace does not guarantee purlin flange

14、 lateral displacement and torsion under， if can brace should consider when calculating constraint purlin flange, should now under the purlin flange 1/3 place to stay with the same Settings, so the purlin design best double brace. 本文為互聯(lián)網(wǎng)收集，請(qǐng)勿用作商業(yè)用途文檔為個(gè)人收集整理，來源于網(wǎng)絡(luò)2. Continuous purlin calculation Usual

15、ly choose Z type purlin, opening direction toward the eaves。 Since Z type purlin overlap forms are available， and it can be such a purlin assumed to continuous artifacts. （1) using lap than simply supported continuous purlin Z purlin internal force distribution is uniform， stiffness big, quantity of

16、 steel can be saved。 （2) continuous purlin overlap overlap area exists in support nested flabby phenomenon， its stiffness is smaller than the cross-section stiffness of the single continuous purlin, therefore had a certain moment release in the bearing, the bending moment in the span have increased.

17、 (3) continuous purlin overall stability calculation is not yet perfect, the available roofing envelope on overall stability and brace support system. (4) continuous purlin bending moment is greater than the cross of bending moment of the bearing， bearing capacity according to the two overlapping ar

18、ea purlin bending modulus of the sum of the consideration is reasonable， can greatly save the steel quantity. （5） continuous purlin of the lap length should not be less than 10% span length， the lap length according to the bending moment distribution of end span and middle span were considered， with

19、 overlapping end bending moment is not greater than midspan moment for the conditions to determine the lap length can make the design more economical and reasonable. （6) made roof purlin and longitudinal compressive bar， single purlin when can not meet the requirement of the bearing capacity of doub

20、le purline are available， and this method saves the quantity of steel. （7) continuous purlin beam connections should be used with the roof and purlin plate bolt connection in case of purlin local web buckling and overall overturning. When high purlin web thickness is larger fashion should be added a

21、 thicker gasket to improve its bearing capacity。 (8） in general, the design with a knee brace purlin, the beneficial effect of the knee brace to the purlin and adverse effects cancel each other out， may be considered negligible, to simplify the design Second， metope purlin 1。 The simply supported be

22、am wall is calculated Usually choose C purlin， opening towards according to actual situation。 Wall beam with opening up commonly， but humanly scaled mouth underside purline allows purlin opening downwards arranged to meet the needs of the fixed frame. Wall beam design and roof purlin is similar， als

23、o want to consider wallboard. Restriction in brace。 Is different panels are self supporting and self supporting two kinds， according to particular case is particular analysis. In addition. When wall beam design according to the different tectonic conditions want to consider the impact of dual bendin

24、g plate。 According to technical specification for the cold bending thin-wall steel structure 8.3.1 and provisions that， on both sides of the hang hang wallboard wall beam and side wall. On the other side can not prevent the torsional deformation of rod wall beam， but excluding double moment of impac

25、t？ (that is， the option B = 0)， but only the strength of the wall beam calculation at this time. 個(gè)人收集整理,勿做商業(yè)用途個(gè)人收集整理，勿做商業(yè)用途For wind suction flange in the stability calculation， like roofing purline, wallboard generally USES self tapping screw and purlin fixed， can think outside wallboard can prevent

26、 wall beam flange lateral instability。 Brace is set in the wall beam inside more economic than increasing the purlin section. For the bearing wallboard, can be set up only in the inside of the brace。 For non self bearing wallboard, appropriate is set in and out of the wall beam dual lateral brace, t

27、he lateral brace can be used as wall panel in the weight of the wall beam under the action of vertical support。 On top of the wall panel and window of the wall beam should be set at the same time suspension and straight poles， would transmit the force to rigid frame column or wall frame column, the

28、bottom of the wall beam fixed on the low wall or wall battlements commonly， the overall stability guaranteed， so the article didn't set at the bottom of the wall beam suspension and poles. 文檔為個(gè)人收集整理，來源于網(wǎng)絡(luò)本文為互聯(lián)網(wǎng)收集，請(qǐng)勿用作商業(yè)用途Three, brace is set Brace is small， effect. Actually have purlin is pressed

29、 steel plate light deformation and torsion, reduce the purline length calculation， ensure the lateral stability of purlin. Brace general through bolts and purlin connection, brace and roof plate can effectively improve the function of purlin of the torsion degree of whole and reduce the external load caused by the reverse effect。 Although under the purlin flange near any brace has a great influence on the flexural bearing capacity of purlin, but when meet brace intensity， stiffness of the brace effect on bending and bending bearing capacity can be ignored. So