Theoretical Calculation of Ultimate Bearing Capacity and Fatigue of Safety Pin of Transmission Tower

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1 Avalable onlne a Energy Proceda 17 (2012 ) Inernaonal Conference on Fuure Elecrcal Power and Energy Syem Theorecal Calculaon of Ulmae Bearng Caacy and Fague of Safey Pn of Tranmon Tower Ju Yan-zhong,Zhang Jan-lu,Jang Fe School of Cvl Engneerng,Norhea Danl Unvery,Jln,Chna Abrac In h aer, he hazard of normal oeraon ower lne caued by ranmon lne cng analyzed. On he ba, everal echnology mean of revenng he hazard of ranmon lne cng n ower grd n Chna are ummarzed. A new knd of overload roecon fng whch afey n degned n h aer, whch can make ranmon lne docae from ower when ce hckne exceed he numercal value ha ulmae load relaed. And hen collae of ower ranmon ower and dconnecon of ranmon are revened and he goal of avodng and decreang he ce daer acheved. Ulmae bearng caacy of afey n reearched baed on elac-lac heory and elac lm load and lac lm load of afey n are obaned. Fnally, alyng Palmgren Mner lnear fague damage accumulaon rule, fague lfe of afey n calculaed Publhed by by Elever Ld. Ld. Selecon and/or and/or eer-revew under under reonbly of Hanan of [name Unvery. organzer] Oen acce under CC BY-NC-ND lcene. Keyword:ranmon lne ower; afey n; ulmae bearng caacy; fague 1.Inroducon In he early 2008' ce-and-now daer Sae Grd Cororaon uffered erou damage. Th ceand-now daer caued drec roery loe of bllon yuan and o-daer reconrucon and rehablaon need o nve 39 bllon yuan[1]. In h ce-and-now daer, he number of ower collae and damage n he 500KV ranmon lne n Sae Grd Cororaon reecvely 506 and 142; 220KV 821 and 239; 110KV 1788 and 421; 35KV 2305 and 1041.The lo of ranmon lne ower o erou ha nfluence o normal oeraon of ranmon lne greae and reconrucon he mo dffcul Publhed by Elever Ld. Selecon and/or eer-revew under reonbly of Hanan Unvery. Oen acce under CC BY-NC-ND lcene. do: /j.egyro

2 1058 Ju Yan-zhong e al. / Energy Proceda 17 ( 2012 ) Mehod of Prevenng Tranmon Lne Icng Alhough now n he world he falure caued by ce-coang unable o be revened comleely, hrough uch meaure a de-cng, on-lne monorng and an-cng he degree of damage can be reduced effecvely[2]. De-cng ale he meaure of changng lne degn and mrovng Lne Degn Crera; ce Condon monorng ale he yem of on-lne monorng o oberve ce condon of ranmon lne ower, conducor and nulaor of remoe area n he conrol room; ce-melng ale echnology of hor-crcu curren. Bu he meaure have many roblem n he effcency for he major naural daer and effec and mu connue o be reearched. Reearcher need o exlore a new way o reven daer acvely. The reearch of degn mehod revenng daer acvely and he exloaon of afey devce conrolled auomacally n he ranmon lne can reduce 90% of he lo n he degn crera, bu conrucon nvemen he ame. The afey n whch a knd of overload roecon hardware can make ranmon lne docae from ower o reven ower collae, reduce loe and rear quckly when ce hckne exceed he numercal value ha relae o he ulmae load. 3.Degn of Safey Pn The locaon of afey n ha grea nfluence on ower-lne earaon, o varou locaon of nulaor rng hould be calculaed accuraely and he oon of he mnmum rengh he locaon of afey n. Takng no accoun rear he locaon whch alled n he lace of nulaor rng and over nulaor rng narorae, becaue kr edge of nulaor rng wll be njured when rng fallng aar mac wh he ground. A la he locaon of afey n alled n he lace of hexagon head bol wh l n hole on hank connecng hank lnkng ocke-clev eye and yoke lae, a hown n Fgure 1. Selecon of maeral manly deend on her rengh and manufacurng echnque ec and make a grea dfference on dmenon degn of afey n, o maeral roceng mu be conen wh maeral eleced n he degn drawng. Th aer chooe maeral for Q235. Safey n lay a role n connecon of hexagon head bol wh l n hole and earaon, o cro econ make a b change n orgnal cro econ of hexagon head bol wh l n hole, a hown n fg.2. Shank lnkng ockeclev eye elec WS-16 and yoke lae elec L Thee wo knd of hardware can mee he ze of degn. Fg.1 Locaon dagram Fg.2 Schemac dagram The afey n locaed n hexagon head bol wh l n hole on hank lnkng ocke-clev eye and yoke lae. To make ower-lne earaon hrough rengh falure of afey n, mechancal behavor of afey n analyzed accuraely and he value equal o load of uended rng. Load of uended rng mu be calculaed accuraely o enure ower-lne earaon on occaon and work normally n oher oerang condon. Load of uended rng comoon of vercal load and horzonal load of mulle conducor. Through calculaon load of uended rng are 59702N, N and N n oerang condon of wnd, he lowe emeraure and broken-wre. The load of conrollng ower-lne earaon whch 130KN can mee engneerng requremen.

3 4.Analy of Ulmae Bearng Caacy of Safey Pn Ju Yan-zhong e al. / Energy Proceda 17 ( 2012 ) Calculaon Model Connecon of afey n a looe connecon and ome ga beween hank lnkng ocke-clev eye and yoke lae. So narorae ha he connecon calculaed by hear bearng caacy. The calculaon mu conder flexural rengh and bendng force key. Calculaon model of afey n hown n fg.3.the calculaon model mlfed a mly uored beam under drbued load. 4.2.Calculaon of Sre Concenraon Facor Fg.3 Dagram of calculaon model Under he load of conrollng ower-lne earaon annular noch of afey n roduce re concenraon and hen rengh falure of afey n occur. So ranmon lne ower can be roeced rough ower-lne earaon. Sre concenraon facor of annular noch calculaed accordng o Formula 1[6]. 2 3 K [( q0.0071q q q ) ( q4.7083q 6.382q (1) q ) y( q q q q ) y ( q K q q q ) y [ ] K r K, 0.6, a Where, q r , y a D noch arameer, K [ and ] K, are re concenraon facor of ecal noch. K r 0.6, a Sre concenraon facor ( K ) calculaed hrough Formula 1 and Calculang Ulmae Bearng Caacy Calculaon model of afey n mlfed a ranvere bend of mly uored beam and belong o roblem of lane re. Sre comonen : y z xy yz zx 0 (2) x ( x, z) Formula 1ubued mahemacal exreon of me yeld condon:.becaue afey n ex re comonen he yeld condon of noch :

4 1060 Ju Yan-zhong e al. / Energy Proceda 17 ( 2012 ) (3) K The edge of afey n fr ar he lac deformaon n he elac age and now afey n he elac lm ae. Elac lm momen : 1 3 M e d 32 K A he lead ncreae, he ae of afey n change from elac ae o lac flow ae. Now he enre cro econ of afey n n he yeld ae. Plac lm momen : 2 d 2 d 2 0 x M 4 y ydy d y d 2 d 2 =4 y dy y ydy When 0, 1 3 M d. The momen of noch 1 M qab. When M 6 K 2 M, afey n e n he elac lm ae. Elac lm load : 3 d qe 16Kab (4) When he load ncreae o ceran value he enre cro econ of afey n n he lac ae. Now he load lac lm load: 3 d Through calculaon, q N / mm e q (5) 3 K ab q N / mm.changng no concenraed load: Fe qeb 67KN, F qb 114KN.When afey n n he elac lm ae afey n urn no degree-of-freedom rucure and lo caacy. Afer a b load ncreaed afey n fracure n he noch. So ranmon lne ower can be roeced by he ower-lne earaon. Through calculaon load of uended rng are 59702N, N and 56030N n oerang condon of wnd, he lowe emeraure and broken-wre. They were le han he elac lm load (67KN) and o afey n mee he engneerng requremen. Becaue he ulmae load whch calculaed accordng o deal elac-lac model maller he error of calculaed value and he load of conrollng ower-lne earaon can mee requremen. 5.Analyzng Fague of Safey Pn Tranmon lne would vbrae dfferenly becaue of he role of wnd. The mechancal force of he vbraon wll a o he afey n and hen fague damage of afey n wll occur afer varou alernang re neny reache ceran neny. Fague lfe of afey n an moran facor of degnng afey n and o h aer calculaed fague lfe of afey n. 5.1.S-N Curve of he Maeral of Safey Pn To calculae fague damage of afey n S-N curve need o be ge. S-N curve of afey n need o be amended becaue econ ze and oher facor of afey n change. Baed on lea quare mehod equaon of S-N curve obaned:

5 Ju Yan-zhong e al. / Energy Proceda 17 ( 2012 ) lg N a b lgk Where N and are reecvely re level and cycle. Charle Machne Degn Manual wa: a b K K D 1 K K fague noch facor and b ze effec facor. 1 coeffcen of urface 0.88 A Q roceng. Through calculaon, 1 6, Q Look-u able wa b =0.345,A= K heorecal re concenraon facor. Look-u Charle Machne Degn Manual wa 2.8. Through calculaon, K 2.1, K D 2.5. The modfed S-N curve exreon : lg N lg2.5 (6) D 5.2.Theorecal Calculaon of Fague Lfe Requremen of degnng of fague lfe are fague damage doe no occur whn a ceran erod of me. To emae fague lfe he calculaon mu elec accumulaed damage creron of fague bede S-N curve. Th aer elec Mner lnear cumulave damage crera and exreon : l n D= 1 (7) N n are cycle correondng of cycle N:, he ercenage of crculang correondng N are cycle of maeral. When fague damage occur he oal number 1 N 1/ N. The formula whch emae fague lfe : N Y (9) ' N ' N he oal number of cycle and N number of cycle of he year. Bede all ac load of ranmon lne vbrang load nclude dynamc load whch ha a ceran frequency. In h aer, number of vbraon of dynamc load calculaed a Webull drbuon whch analyze drbuon arameer of wnd eed. Wnd eed range whch caue aeolan vbraon of ranmon lne 0.510m/. Frequency range of vbraon of ranmon lne, whch calculaed accordng o he rojec arameer, beween 3Hz75Hz. In he raccal calculaon, frequency range of vbraon of ranmon lne dvded no 15 frequency band every 5Hz. Tme of vbraon, number of vbraon and dynamc load of every frequency band are calculaed. Under he dynamc load Van Mee re of afey n hown n Tale.1. TABLE I THE LOADS SPECTRUM OF SAFETY PIN Frequency Band Hz Number of Vbraon Dynamc Load (MPa) Percenage of Crculang Cyclc Sre Fague lfe E+07 1e E+08 1e E E E (8)

6 1062 Ju Yan-zhong e al. / Energy Proceda 17 ( 2012 ) E E E E E E E E E E Trough calculaon of Formula 8 he oal number of cycle : N 1/ N Trough calculaon of Formula 9 fague lfe of afey n Y a The reul mee he degn requremen of afey n. 6.Concluon and Proec Th aer degn afey n whch a knd of overload roecon hardware for he 5A ZM4 ranmon ower n he Sae Grd Tycal Degn Tranmon and Drbuon Projec.The afey n can make ranmon lne docae from ower and reven collae of ower ranmon ower and dconnecon of ranmon lne when ce hckne exceed he numercal value ha ulmae load relaed. Baed on elac-lac heory, elac lm load and lac lm load of afey n are 67KN and 114KN.In he normal condon he load of afey n le hen elac lm load and afey n mee oeraon requremen. The error of lac lm load and he load of conrollng ower-lne earaon Afer a b load ncreaed afey n fracure n he noch. Now afey n can make ranmon lne docae from ower and hen reven ower. Fague lfe of afey n whch calculaed a Palmgren Mner lnear fague damage accumulaon rule 14.6 year. So he reul how ha he degn of afey n can mee rojec requremen. Th aer nroduce heorecal calculaon of afey n n deal. To acheve he uroe of relable oeraon hee concluon need o be verfed hrough fne elemen analy and exermen. Reference [1] Yang Jngbo, L Zheng.Analy of he feaure of covered Ice and collaed ower of ranmon lne now and ce aacked n 2008[J]. Advance of Power Syem & Hydroelecrc Engneerng, 2008,244:04-08 [2] Wang Jngzhao,Yang Janng,Yang Jngbo.Revew of he ue of cenfc and echnologcal mean of ranmon lne now and ce aacked n 2008[C]. Hu Y. Proceedng of he econd (2009) conference of echnologcal exchange of naonal overhead ranmon lne

7 Ju Yan-zhong e al. / Energy Proceda 17 ( 2012 ) [3] Xu Bngye,Lu Xnheng. Plac lm analy of rucure [M]. Bejng: Chnee Archecure Indury Pre,1985. [4] Xue Shouy. Elac-lac Mechanc[M]. Bejng:Chna Buldng Maeral Indury Publhng Houe,2005. [5] Xu Bngye,Huang Yan, Lu xnheng.elac-la cmechanc and I Alcaon[M]. Bejng: Chna Machne Pre,1984. [6] Ma Png. Sre concenraon facor of ecmen wh annular noch under bendng load[j].journal of Lanzhou Unvery of Techmology.2005,31(3):43-46 [7] Zhao Shaoban,Wang Zhongbao. Fague Degn [M]. Bejng: Chna Machne Pre,1992 [8] Kong dey.reeareh of ranmon lne aeolan vbraon baed on dynamc mehod[d].wuhan: Huazhong Unvery of Scence and Technology,2009 [9] Dong Je.Elecrc Power Fng Handbook[M].Bejng: Chna Elecrc Power Pre, [10] Cheng Yngang. Power ranmon lne hardware nallaon eng and alcaon degn[m].bejng:waer Reource and Hydroower Pre,1989,6 Bograhe Ju Yanzhong wa born n Da An cy n J Ln, on December 26,n 1963.He graduaed from Norheaern Unvery n January n 1988 and receved a maer degree. He graduaed from Bejng Jjaoong Unvery n Arl n 2004 and receved a docor degree. Now he he reden of cvl engneerng Norhea Danl Unvery. H reearch drecon nclude n ranmon rojec, brdge and rucural emc, rucural healh monorng and dagno and he develomen and alcaon of new maeral. H major ocal a-me nclude member of Chnee Socey for Elecrcal Engneerng, Chnee Socey of Theorecal and Aled Mechanc and J Ln Cvl Engneerng Socey.