维普资讯 http://www.cqvip.com V01.15 No.2 Apt.2007 Article ID:1005-2429(2007)02-0122-04 Influence of Track Parameters on Welded Turnout Group xu Qing.yuan(徐庆元) ‘ WANG Ping(王平) QU Xiao.hui(屈晓晖)。 LI Shu.de(李树德)。 J.School ofCivil Engineering,Southwest Jiaotong University,chegndu 610031,China 2.College ofCivil and Architectural Engienerign,Centrla South University,Changslm 410075,China 3.No.3 Rndw ̄Stuvey and Design Institute,Tianifn 300142,Chian Abstract By building the finite element model,the track parameters,including the ulitmate longitudinal resistance,the length of the nitermediate straight lnie,and the gap between spacer blocks,were analyzed for their influences on the longitudinal forces and displacements of hte snigle turnout and turnout group,respectively.The results indicate that when hte longiutdinal ersistance drops from 32 to 20 N/on,the maximum additional longiutdinal force of the turnout group increases by 19.2%,and the maximum daditional longitudinal displacement of the turnout group grows by 85.3%compared 血50.4%for the single turnout.When the length ofintermediate straight line rises from 0 m to infiniet,the maximum additional longitudinal force decreases by 38.8%,and hte maximum additional longitudinal displacement by 80.3%. Key words Railway engineering;Welded turnout group;Finite element method;Continuous welded rail Introduction few papers 一 on the turnout group investigated the influence of the link style.In this paper,using the fi- Welded turnout is a key part for continuous nite element method.the authors take the No.12 welded rails(CW-Rs).Longi tudinal force and dis- welded turnout wiht integrated cast frog in China for placement of rails should be considered in the design instance,to study the influence of track parameters on of welded turnout.When the distance between the additional longiutdinal force and displacement of the welded turnouts at places like railway stations is small,the additional longitudinal force and displace- welded turnout group.The idsplcaements nad longitu- idnal forces of the single turnout and turnout group ment of hte turnouts interact with each other;thus the wiht different parameters were calculated,and the re- sum effect is too significant to be neglceted.Although some studies were conducted on the topic[ suits are naalyzed. 。htey were mainly focused on single turnout.In addiiton,a 1 Mechanical Model hTe fniiet element model of a welded turnout group is shown in Fig.1.The system consists of Received 2oo6—O2—27 rails,sleepers and ballasts.The rail and sleeper ale Foundation item The Doctoral Fund of Ministry of Educa- regarded as beam element.The rail is divided by the tionof China(No.20050613007) Biography XU Qing-yuan(1972一),associate professor, contact point betwen the rail and sleeper,and the PhD.His research of interest is in continuous welded rails sleeper is segmented wiht an interval of 0.1 m.The }Corresponding author.Te1.:+86-13752336915;E-mail: rail and sleeper rae connected witll a nonlinear spring. xuqingyuan@cr-tsdi.corn so ale sleeper and ballsat,switch rail and stock rail, 维普资讯 http://www.cqvip.com XU r学 伽et a1./ 岍搿ofTrack Parameters On Welded Turnout Group and frog and point rail(see Figs.1(a)and(b)). vector;P is load vector.To solve the above equation, The area affected by turnouts is supposed within Newton’S iteration method is used to obtain solutions at 100 m.Beyond the area,suppose that the rails do not each temperature. expand or contract.Initially,there is no temperature drop or rise,and the turnout group is stress—free. 2 Case Study Consider the compression strain energy of rail el— Take the No.12 high-speod turnout with il】 锄ed ements,the curvature strain energy of the sleeper and cast frog as an example.,nle related parameters are list— na array of strain energies in the nonlinear springs that ed below:60 kg/m rail with elastic modulus of2.058× simulate respectively the ballast resistance,the resist— .1inear thermal expansion coefifcinet of 11.8× nate between spacer blocks,the resistance betwen 10 /oC,and hte section area of95.04×10一 :( 一 hte stock rail nad the heel of the switch rail,and the nese SII sleeper with a space of0.6 m and elastic mode- ersistance between the frog heel and the point rail. Isn of4.2×10' .and the moment of inertia of 2.5 Besides,the torsion strain energy in the nonlinear ×10 I .,nle gap betwen spacer blocks is 7 mm.ul- spring are considered,which simulates the torsional thmte longitudinal resistance of the ballast with 2 mm resistance between the rail and sleper(see Hg.1(c)). silde is 32 N/cm,and the rise of rail texture is 50 oC.Ultimate longitudinal resistance of fasteners is 12 for one group. ,nle calculated addiitonal longitudinal force nad dis- …~Sleeper element——Rail elmeent x JOint elmeent placement of hte straihgt stock rail are shown ni Figs.2 (a)Turnout group nad 3,respectively. Ⅳ×O.1m :。 0 0 0 : ■。 、 (b)Force transmission between the sleeper and ballast /m Hg.2 Additional longitudinal force /m (C)Force transmissino ebtween the rail nad sleeper 盹.1 Mechanical model According ot hte principle of minimum optential en- 星 ergy,the optential energy ofthe system刀 is the sum of all the energies.From stagnation point condiiton, 讽/拟=O,the balnace equations are Ku=P,where K iS stit_ ̄eSS matrix of the elements:l‘iS displacement 维普资讯 http://www.cqvip.com 124 intermediate straight line all influence the longitudinal 3 Results and The longitudinal resistances of the ballast and fas— tenets,the gap between spacer blocks and the length of force and displaceraent.To get the picture of their im- pacts,these patame ̄l'S are changed respectively,and the results ale presented in Tables 1-4. Table 1 Calculated results with different ultimate longitudinal resistances of the ballast Table 2 Calculated results with diferent longitudinal resistances ofthe fasteners Table 3 Calculated results of the turnout group with different lengthes of the intermediate.straight line Table 4 Calcdated results with diferent gaps between spacer blocks From the calculated results,we draw the following no obvious influence on the additional longitudinal force Of the single turnout.However.it has nm significant conclusions: (a)The longitudinal resistance of the ballast has influence on the turnout group.Whgil the longitudinal 维普资讯 http://www.cqvip.com XU q/ng-y,,an et a/./Inlufence ofTrack Parameters On tFe/ded Turnout Croup resistance drops fi-om 32 to 20 N/cm,the maxiinuIll ad- ditional longitudinal force of the turnout group increases 125 to the turnout group.In addition,with the increase of gap limit of spacer blocks,the shear force decreases sharply.The longitudinal resistance of the ballast has much more si ̄ificant influence on the turnout group, by 19.2%,and the maxinluln additional longitudinal ctisplacen ̄t ofthe turnout group grows by 85.3%tom- pared with 50.4%for the single turnout.The longitudi- nal resistance of the ballast has small influence on the shear force of spacer blocks of the single turnout and turnout group. i.e.,it can greatly decrease the additional longitudinal force and the displacement.In practice,much attention should be paid to the quality ofthe ballast to benefit the turnout group. (b)rI1le longitudinal resistance fi-om the fasteners has little influence on the additional longitudinal force and displacement.It mainly impacts the shear force of References [1]Cai C B,一Thai W M,Wang Q C.Temperala ̄force and die,meirt in welded switches 0f speed-rai ̄g railways [J].Journa/oy Southwest Jiaotong University,1997,32 (5):513-517(in claine,se). spacer block.The longitudinal resistance has mole sig- nificant influence on the turnout group than on the single turnout. (c)The length ofintermediate straight line llas sig- niifcant influence on the additional longitudinal force and displacement.When the length of intermediate straight line rises if-om 0 m to infinite,the maximum additional longitudinal force decreases by 38.8%.and the imxi— illllm additional longitudinal displacement by 8o.3%. shear force of the spacer block is barely influenced by the length of intermediate straight line. [2]Cai C B,Wang Q C.Analysis ofrail temperature stress and displ ̄ment of welded switch 3orJ].Journa/oythe Oz/na P,a//way Soc/ety,1999,21(4):51-54(in aline). [3]Wang P,Huang S S.s'mdy on the nonlinear en,ce,2001,22(1):84-91(in Oain ̄). ofweld- ed lumout with movable-point fro ̄[J].a Ra//way Sci- [4]Ma Z G.The analysis and rese ̄h of longituaimi f ̄'ee of NO.骝turnout eormeeted with CWR on( n—Shen railway [J].China P,ai/way Sc/ence,加02,23(2):71-74(in Clai- nese). (d)1he additional longitudinal force,the addition- al longitudinal displacement,the shear force ofthe spac— er block all decrease si ̄ificantly with the increase of the gap of spacer blocks.Compared winl that on the sin- gle turnout.the gap between the spacer blocks has smal- ler illtluence on the turnout group. [5]Fan J J,Gu A J,Cllen Y Y. e0 caleulalion and testing analysis for continuous welded turnouts[J].]ourna/ oythe China Ra//way Soc/ety,2O0O,22(2):55-59(in Chi- nese). [6]Wang P.Study On influences of welded tunourt group on displacements and longitudin ̄forces ofrails[J].]ourna/oy the Ch/na Ra/1way Soc/ety,加02,24(2):74—78(in Clai- nese). 4 Ending Remarks model is built on the condition of the force equilibrium.The calculation results show that increasing the longitudinal resistances of the ballast and fasteners, and the length of intermediate straight line is beneficial [7]I-i Q Y,Claen X F.Analysis of working efect of welded tllmout[J].Journa/oythe Ch/na Ra/1way Society,加02,24 (5):84-88(in oainese).