Ezimweni ezehlukene zesakhiwo, onjiniyela bangase badinge ukuhlola amandla amalunga enziwe ama-weld kanye nezinsimbi zokubopha.Namuhla, izibophelelo zemishini ngokuvamile zingamabhawudi, kodwa imiklamo emidala ingase ibe nama-rivets.
Lokhu kungenzeka ngesikhathi sokuthuthukiswa, ukulungiswa, noma ukuthuthukiswa kwephrojekthi.Idizayini entsha ingase idinge ukubhilidiswa nokushiselwa ukuze kusebenze ndawonye endaweni lapho okokusebenza okuzohlanganiswa kuhlanganiswe kuqala bese kushiselwa ukuze kunikeze amandla aphelele ekuhlanganyeleni.
Kodwa-ke, ukunquma umthamo ophelele womthwalo wejoyinti akulula njengokwengeza isamba sezingxenye ngazinye (ama-welds, ama-bolt, nama-rivets).Ukucabanga okunjalo kungaholela emiphumeleni eyinhlekelele.
Ukuxhuma okuboshiwe kuchazwe ku-American Institute of Steel Structures (AISC) Structural Joint Specification, esebenzisa amabholithi e-ASTM A325 noma A490 njengokukhweza okuqinile, ukulayisha kuqala, noma ukhiye wokuslayida.
Qinisa ukuxhumana okuqiniswe ngokuqinile ngesikrufu esinomthelela noma umkhandi wokukhiya usebenzisa isikrufu esivamile esinezinhlangothi ezimbili ukuze uqinisekise ukuthi izendlalelo zixhumene ngokuqinile.Kuxhumo olucindezelwe ngaphambili, ama-bolts afakwa ukuze abe ngaphansi kwemithwalo ebalulekile eqinile, futhi amapuleti angaphansi kwemithwalo yokucindezela.
1. Vula inati.Indlela yokuguqula i-nati ihlanganisa ukuqinisa i-bolt bese uphendulela i-nati imali eyengeziwe, okuncike kububanzi nobude bebhowudi.
2. Linganisa ukhiye.Indlela ye-wrench elinganisiwe ikala i-torque ehlotshaniswa ne-bolt tension.
3. Ibhawodi yokulungiswa kokuqina kohlobo lwe-torsion.Ama-twist-off tension bolt anezikhonkwane ezincane ekupheleni kwebhawodi okuphambene nekhanda.Lapho i-torque edingekayo ifinyelelwa, i-stud iyasuswa.
4. Inkomba yokudonsa eqondile.Izinkomba eziqondile zokungezwani amawasha akhethekile anamathebhu.Inani lokucindezelwa ku-lug libonisa izinga lokucindezeleka elisetshenziswe ku-bolt.
Ngokwamagama abantu abavamile, amabhawodi asebenza njengezikhonkwane emajoyintini aqinile futhi aqine kakhulu, njengephini lethusi elibambe isitaki sephepha elinembobo ndawonye.Amajoyinti abalulekile ashelelayo asebenza ngokungqubuzana: ukulayisha kuqala kudala ukwehla kwamandla emali, futhi ukungqubuzana phakathi kwezindawo zokuthintana kusebenza ndawonye ukumelana nokushelela kwelunga.Kufana ne-binder ebamba inqwaba yamaphepha ndawonye, ​​​​hhayi ngoba izimbobo zibhodlozwa ephepheni, kodwa ngenxa yokuthi i-binder icindezela amaphepha ndawonye futhi ukungqubuzana kubamba isitaki ndawonye.
Amabhawodi e-ASTM A325 anamandla amancane aqinile angama-150 kuya ku-120 kg nge-intshi yesikwele (KSI), kuye ngedayamitha yebhawodi, kuyilapho amabhawodi e-A490 kufanele abe namandla aqinile we-150 kuya ku-170-KSI.Amalunga e-Rivet aziphatha njengamajoyinti aqinile, kodwa kulokhu, izikhonkwane zingama-rivets ngokuvamile aqinile cishe uhhafu njengebhawodi ye-A325.
Enye yezinto ezimbili ingenzeka lapho ilunga eliboshelwe ngomshini lingaphansi kwamandla okugunda (lapho into eyodwa ijwayele ukushelela phezu kwenye ngenxa yamandla asetshenzisiwe).Ama-bolts noma ama-rivets angaba sezinhlangothini zezimbobo, okubangela ukuthi ama-bolts noma ama-rivets aphuce ngasikhathi sinye.Okwesibili okungenzeka ukuthi ukungqubuzana okubangelwa amandla okubamba ama-fasteners enziwe sengathi angakwazi ukumelana nemithwalo yokugunda.Akukho ukushelela okulindelekile kulokhu kuxhumana, kodwa kuyenzeka.
Uxhumano oluqinile luyamukeleka ezinhlelweni eziningi, njengoba ukushelela kancane kungeke kuthinte kabi izici zokuxhuma.Isibonelo, cabanga ngesisele esidizayinelwe ukugcina impahla eyimbudumbudu.Kungase kube khona ukushelela okuncane uma ulayisha okokuqala.Uma ukushelela sekwenzekile, ngeke kuphinde kwenzeke, ngoba yonke imithwalo elandelayo inohlobo olufanayo.
Ukuhlehliswa komthwalo kusetshenziswa kwezinye izinhlelo zokusebenza, njengalapho ama-elementi ajikelezayo engaphansi kwemithwalo eshubile necindezelayo.Esinye isibonelo into egobayo engaphansi kwemithwalo ehlehla ngokugcwele.Uma kunoshintsho olubalulekile endleleni yokulayisha, kungase kudingeke uxhumano olulayishwe ngaphambili ukuze kuqedwe ukushelela kwe-cyclic.Lokhu kushelela ekugcineni kuholela ekusheleleni okwengeziwe emigodini emide.
Amanye amalunga abhekana nemijikelezo eminingi yomthwalo engaholela ekukhathaleni.Lokhu kufaka phakathi imishini yokunyathelisa, izisekelo ze-crane kanye nokuxhumana kumabhuloho.Ukuslayida ukuxhumana okubalulekile kuyadingeka lapho ukuxhumeka kungaphansi kwemithwalo yokukhathala ohlangothini olubuyela emuva.Kulezi zinhlobo zezimo, kubaluleke kakhulu ukuthi ilunga lingasheleli, ngakho-ke amalunga abucayi ayadingeka.
Ukuxhumana okukhona okuboshiwe kungaklanywa futhi kwenziwe kunoma yimaphi alawa mazinga.Ukuxhumana kwe-rivet kubhekwa njengokuqinile.
Amajoyinti ashiselwe aqinile.Amajoyinti e-solder akhohlisayo.Ngokungafani namajoyinti aqinile, angakwazi ukushelela ngaphansi komthwalo, ama-welds akudingeki anwebe futhi asabalalise umthwalo osetshenzisiwe ngezinga elikhulu.Ezimweni eziningi, izinsimbi zomshini ezishiselwe futhi ezithwele azigugi ngendlela efanayo.
Lapho ama-weld esetshenziswa ngezinsimbi zokubopha ngomshini, umthwalo udluliselwa ngengxenye enzima, ngakho-ke i-weld ingathwala cishe wonke umthwalo, ngokuhlanganyela okuncane kakhulu ne-bolt.Yingakho kufanele kuqashelwe uma welding, bolting futhi riveting.Imininingwane.I-AWS D1 ixazulula inkinga yokuxuba izibophelelo zemishini namashisela.Ukucaciswa kwe-1: 2000 ye-welding yesakhiwo - insimbi.Isigaba 2.6.3 sisho ukuthi kuma-rivets noma amabhawodi asetshenziswa kumajoyinti ohlobo oluthwele (okungukuthi lapho ibhawodi noma i-rivet isebenza njengephini), izinsimbi zokubopha akumele zicatshangelwe njengokwabelana nomthwalo wokushisela.Uma i-welding isetshenziswa, kufanele ihlinzekwe ukuze ithwale umthwalo ogcwele endaweni ehlangene.Kodwa-ke, ukuxhumana okushiselwe ku-elementi eyodwa futhi kuboshwe noma kuboshwe kwenye i-elementi kuvunyelwe.
Uma usebenzisa ama-fasteners ohlobo lwe-bearing-type futhi wengeza ama-welds, umthamo wokuthwala umthwalo webhawodi awunakwa kakhulu.Ngokwaleli lungiselelo, i-weld kumele yakhelwe ukudlulisa yonke imithwalo.
Lokhu kuyefana ngempela ne-AISC LRFD-1999, isigatshana J1.9.Kodwa-ke, indinganiso yaseCanada i-CAN/CSA-S16.1-M94 iphinde ivumele ukusetshenziswa okuzimele lapho amandla esibophelelo somshini noma ibholithi ephakeme kunaleyo yokushisela.
Kulolu daba, izindlela ezintathu ziyahambisana: amathuba okubopha ngomshini wohlobo lokuthwala kanye namathuba ama-welds awahlanganisi.
Isigaba 2.6.3 se-AWS D1.1 siphinde sidingide izimo lapho amabhawodi nama-welds kungahlanganiswa ngokuhlanganyela okuyizingxenye ezimbili, njengoba kuboniswe kuMfanekiso 1. Amashisela kwesokunxele, aboshwe ngakwesokudla.Amandla aphelele wama-welds nama-bolts angacatshangelwa lapha.Ingxenye ngayinye yakho konke ukuxhumana isebenza ngokuzimela.Ngakho, le khodi ihlukile kumgomo oqukethwe engxenyeni yokuqala ye-2.6.3.
Imithetho esanda kuxoxwa iyasebenza ezakhiweni ezintsha.Ezakhiweni ezikhona, isigatshana 8.3.7 D1.1 sithi uma izibalo zesakhiwo zibonisa ukuthi i-rivet noma ibhawodi izolayishwa ngokweqile isamba somthwalo omusha, umthwalo okhona kuphela okufanele unikezwe wona.
Imithetho efanayo idinga ukuthi uma i-rivet noma i-bolt igcwele kuphela imithwalo emile noma ingaphansi kwemithwalo ye-cyclic (ukukhathala), isisekelo esanele sensimbi kanye nama-welds kufanele kwengezwe ukusekela umthwalo ophelele.
Ukusatshalaliswa komthwalo phakathi kwezibophelelo zemishini nama-welds kuyamukeleka uma isakhiwo silayishwe ngaphambili, ngamanye amazwi, uma ukushelela kwenzeke phakathi kwezinto ezixhunyiwe.Kodwa imithwalo emile kuphela ingafakwa kuma-fasteners emishini.Imithwalo ephilayo engaholela ekusheleleni okukhulu kufanele ivikelwe ngokusetshenziswa kwamashisela akwazi ukumelana nawo wonke umthwalo.
Ama-welds kufanele asetshenziselwe ukumelana nakho konke ukulayisha okufakiwe noma okuguquguqukayo.Uma izinsimbi zokubopha sezigcwele ngokweqile, ukwabelana ngomthwalo akuvunyelwe.Ngaphansi kokulayisha okujikelezayo, ukwabelana komthwalo akuvunyelwe, njengoba umthwalo ungaholela ekusheleleni unomphela kanye nokugcwala kwe-weld.
umfanekiso.Cabangela ilunga lethanga ekuqaleni elaliboshwe liqine (bona Umfanekiso 2).Isakhiwo sengeza amandla engeziwe, futhi ukuxhumana nezixhumi kufanele kwengezwe ukuze kunikeze amandla aphindwe kabili.Emkhiwaneni.I-3 ikhombisa uhlelo oluyisisekelo lokuqinisa izakhi.Kufanele kwenziwe kanjani ukuxhumana?
Njengoba insimbi entsha kwakudingeka ihlanganiswe nensimbi endala ngokushisela i-fillet, unjiniyela wanquma ukwengeza amashisela athile ejoyintini.Njengoba ama-bolts ayesekhona, umqondo wangempela kwakuwukwengeza kuphela ama-welds adingekayo ukuze kudluliselwe amandla engeziwe ensimbi entsha, ulindele ukuthi u-50% womthwalo uzodlula ama-bolts kanye no-50% womthwalo ozodlula ama-welds amasha.Kuyamukeleka?
Ake siqale sicabange ukuthi ayikho imithwalo emile esetshenziswayo okwamanje kuxhumo.Kulokhu, isigaba 2.6.3 se-AWS D1.1 siyasebenza.
Kuleli hlanganiso elithwalayo, i-weld nebhawodi ngeke kubhekwe njengokwaba umthwalo, ngakho usayizi we-weld oshiwo kufanele ube mkhulu ngokwanele ukusekela wonke umthwalo omile noshintshayo.Amandla okuthwala ama-bolts kulesi sibonelo awakwazi ukucatshangelwa, ngoba ngaphandle komthwalo omile, uxhumano luzoba sesimweni sokudangala.I-weld (eklanyelwe ukuthwala ingxenye yomthwalo) iqala ukugqashuka lapho kufakwa umthwalo ogcwele.Khona-ke i-bolt, nayo eyenzelwe ukudlulisa isigamu somthwalo, izama ukudlulisa umthwalo futhi iphule.
Cabanga futhi ukuthi kufakwe umthwalo omile.Ngaphezu kwalokho, kucatshangwa ukuthi uxhumano olukhona lwanele ukuthwala umthwalo okhona unomphela.Kulokhu, isigaba 8.3.7 D1.1 siyasebenza.Ama-weld amasha adinga kuphela ukumelana nokukhuphuka kwemithwalo ebukhoma emile futhi evamile.Imithwalo efile ekhona inganikezwa izibophelelo zemishini ezikhona.
Ngaphansi komthwalo oqhubekayo, uxhumano alunciphisi.Kunalokho, amabhawodi asewuthwele kakade umthwalo wawo.Kube khona ukushelela okuthile ekuxhumekeni.Ngakho-ke, ama-welds angasetshenziswa futhi angadlulisela imithwalo enamandla.
Impendulo yombuzo othi "Ingabe lokhu kuyamukeleka?"kuncike ezimweni zokulayisha.Esimweni sokuqala, ngokungabikho komthwalo omile, impendulo izoba yimbi.Ngaphansi kwezimo eziqondile zesimo sesibili, impendulo inguyebo.
Ngenxa yokuthi kusetshenziswe umthwalo omile, akwenzeki ngaso sonke isikhathi ukwenza isiphetho.Izinga lemithwalo emile, ukwanela kokuxhumeka kwemishini okukhona, kanye nemvelo yemithwalo yokugcina-kungakhathaliseki ukuthi i-static noma i-cyclic-ingashintsha impendulo.
UDuane K. Miller, MD, PE, 22801 Saint Clair Ave., Cleveland, OH 44117-1199, Umphathi we-Welding Technology Center, iLincoln Electric Company, www.lincolnelectric.com.I-Lincoln Electric yenza imishini yokushisela nezinto ezisetshenziswayo zokushisela emhlabeni wonke.Onjiniyela kanye nochwepheshe Besikhungo Sokushisela Ubuchwepheshe basiza amakhasimende ukuxazulula izinkinga zokushisela.
I-American Welding Society, 550 NW LeJeune Road, Miami, FL 33126-5671, ifoni 305-443-9353, ifeksi 305-443-7559, iwebhusayithi www.aws.org.
ASTM Intl., 100 Barr Harbour Drive, West Conshohocken, PA 19428-2959, ifoni 610-832-9585, ifeksi 610-832-9555, iwebhusayithi www.astm.org.
American Steel Structures Association, One E. Wacker Drive, Suite 3100, Chicago, IL 60601-2001, ifoni 312-670-2400, ifeksi 312-670-5403, iwebhusayithi www.aisc.org.
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