Mumamiriro akasiyana-siyana ezvimiro, mainjiniya angangoda kuongorora kusimba kwemajoini akagadzirwa nema welds uye ma mechanical fasteners.Nhasi, ma mechanical fasteners anowanzo mabhaudhi, asi madhizaini ekare anogona kunge aine rivets.
Izvi zvinogona kuitika panguva yekuvandudza, kugadziridza, kana kuvandudzwa kweprojekiti.Dhizaini nyowani inogona kuda kubhaudhi uye welding kuti ishande pamwe chete mujoini apo zvinhu zvinofanirwa kubatanidzwa zvinotanga kusungwa pamwe chete uye zvino welded kupa simba rakazara kujoini.
Nekudaro, kuona huwandu hwese hwekuremerwa kwejoint hakusi nyore sekuwedzera huwandu hwezvikamu zvega (welds, bolts, uye rivets).Kufungidzira kwakadaro kungatungamirira kumigumisiro ine ngwavaira.
Mabhaudhi ekubatanidza anotsanangurwa muAmerican Institute of Steel Structures (AISC) Structural Joint Specification, iyo inoshandisa ASTM A325 kana A490 mabhaudhi seyakasimba gomo, preload, kana sliding kiyi.
Simbisa zvinosungirirwa zvakasimba nechipanera chinobata kana chivhariso chekiyi uchishandisa chipanera chine mativi maviri kuti uone kuti maraya ari kudhumana.Mukubatana kwakasimbiswa, mabhoti anoiswa kuitira kuti aise pasi pemitoro yakakosha, uye mahwendefa anoiswa pasi pekumanikidza.
1. Shandura nzungu.Nzira yekushandura nut inosanganisira kusimbisa bhoti uye kushandura nut imwe yakawedzerwa, iyo inobva pahupamhi uye urefu hwebhoti.
2. Gadzirisa kiyi.Iyo calibrated wrench nzira inoyera torque iyo inobatanidzwa nebhaudhi tension.
3. Torsion mhando tension kugadzirisa bhaudhi.Twist-off tension bolts ane matudhi madiki kumagumo kwebhaudhi akatarisana nemusoro.Kana torque inodiwa yasvika, iyo stud haina kuvharwa.
4. Yakarurama dhonza index.Direct tension zviratidzo ma washer anokosha ane ma tabo.Kuwanda kwekumanikidza pagugi kunoratidza huwandu hwekushushikana hunoshandiswa kune bhoti.
Mukutaura kwevasina basa, mabhaudhi anoita semapini akasimba uye asati asungwa majoini, senge pini yendarira yakabata murwi webepa rine maburi pamwechete.Majoini anotsvedza anotsvedza anoshanda nekukweshana: preload inogadzira kuderera, uye kukakavara pakati penzvimbo dzekubatana kunoshanda pamwechete kudzivirira kutsvedza kwejoinhi.Zvakafanana nebhainda rinobata murwi wemapepa pamwe chete, kwete nekuti maburi aroverwa pabepa, asi nekuti bhainda rinodzvanya mapepa pamwechete uye kukwesha kunobata murwi pamwechete.
Mabhaudhi eASTM A325 ane simba shoma re150 kusvika 120 kg per square inch (KSI), zvichienderana nedhayamita yebhaudhi, ukuwo mabhaudhi eA490 anofanirwa kunge aine simba re150 kusvika 170-KSI.Majoini eRivet anoita senge majoini akasimba, asi mune iyi kesi, mapini ari mapini anowanzo svika hafu yakasimba seA325 bhaudhi.
Chimwe chezvinhu zviviri chinogona kuitika kana majoini akasungirirwa akaiswa pasi pesimba rekugera (apo chimwe chinhu chinenge chichiita kutsvedza pamusoro pechimwe nekuda kwesimba rinoshandiswa).Mabhoti kana rivets anogona kunge ari pamativi emakomba, zvichiita kuti mabhaudhi kana rivets rigere kure panguva imwe chete.Chechipiri chingangoitika ndechekuti kukwesha kunokonzerwa nechisimba chekusunga chezvibatiso zvekunyepedzera zvinokwanisa kumira mitoro yeshear.Hapana kutsvedza kunotarisirwa pakubatanidza uku, asi zvinogoneka.
Kubatana kwakasimba kunogamuchirwa kune akawanda maapplication, sezvo kutsvedza kushoma hakugone kukanganisa maitiro ekubatanidza.Semuenzaniso, funga nezve silo yakagadzirirwa kuchengetedza granular zvinhu.Panogona kuve nekutsvedza kushoma paunenge uchirodha kekutanga.Kana kutsvedza kwaitika, hazvizoitike zvakare, nekuti mitoro yese inotevera ndeyemhando imwechete.
Kudzoserwa kwemutoro kunoshandiswa mune mamwe maapplication, senge kana zvinhu zvinotenderera zvichiiswa pasi pekuchinjana kusimba uye kumanikidza mitoro.Mumwe muenzaniso chinhu chinokotama chinoiswa pasi pemitoro yakazara.Kana paine shanduko yakakosha munzira yekuremerwa, chinongedzo chakatakurwa chinogona kudikanwa kubvisa cyclic slip.Kutsvedza uku kunozopedzisira kwaita kuti kutsvedza kwakawanda mumakomba akareba.
Mamwe majoini anosangana nemitoro yakawanda inotenderera iyo inogona kutungamirira kune kuneta.Izvi zvinosanganisira ma press, crane zvinotsigira uye zvinongedzo mumabhiriji.Kutsvedza kwakakosha kubatanidza kunodiwa kana iyo yekubatanidza ichiiswa kune kuneta mitoro munzira yekudzokera kumashure.Kune marudzi aya emamiriro ezvinhu, zvakakosha zvikuru kuti chibatanidza chirege kutsvedza, saka majoini anotsvedza anodiwa anodiwa.
Mabhaudhi aripo ekubatanidza anogona kugadzirwa uye kugadzirwa kune chero eaya zviyero.Rivet yekubatanidza inoonekwa seyakasimba.
Welded majoini akaoma.Solder majoini anonyengera.Kusiyana nemajoini akasungwa, ayo anogona kutsvedza pasi pemutoro, welds haafaniri kutambanudza uye kugovera mutoro wakashandiswa kusvika pamwero mukuru.Muzviitiko zvakawanda, ma welded uye anotakura mhando mechanical fasteners haaparadze nenzira imwechete.
Kana ma welds anoshandiswa nema mechanical fasteners, mutoro unotamiswa kuburikidza nechikamu chakaoma, saka weld inogona kutakura inenge yose yemutoro, ine zvishoma zvakagoverwa nebhaudhi.Ndicho chikonzero kuchenjerera kunofanira kutorwa kana welding, bolting uye riveting.Zvinotsanangurwa.AWS D1 inogadzirisa dambudziko rekusanganisa ma mechanical fasteners uye welds.Tsanangudzo 1: 2000 yekugadzirwa kwesimbi - simbi.Ndima 2.6.3 inotaura kuti kune rivets kana mabhaudhi anoshandiswa mukubereka-mhando majoini (kureva apo bhaudhi kana rivet rinoshanda sepini), ma mechanical fasteners haafanirwe kutariswa kugovera mutoro neweld.Kana welding ikashandiswa, inofanirwa kupihwa kutakura mutoro wakazara mujoinhi.Nekudaro, zvinongedzo zvakasungirirwa kune chimwe chinhu uye riveted kana bolted kune chimwe chinhu zvinotenderwa.
Paunenge uchishandisa bearing-type mechanical fasteners uye kuwedzera welds, kutakura-kuremedza simba rebhoti kunonyanya kuregererwa.Zvinoenderana nechirongwa ichi, weld inofanirwa kugadzirwa kuendesa mitoro yese.
Izvi zvakangofanana neAISC LRFD-1999, clause J1.9.Zvisinei, iyo Canadian standard CAN/CSA-S16.1-M94 inobvumirawo kumira-yega kushandiswa kana simba re mechanical fastener kana bhaudhi rakakwirira kudarika iro rekugadzira.
Munyaya iyi, maitiro matatu anowirirana: mikana yekusungirirwa kwema mechanical yemhando yekutakura uye mikana ye welds haiwedzere.
Chikamu 2.6.3 cheAWS D1.1 chinokurukurawo mamiriro ezvinhu apo mabhoti uye welds zvinogona kusanganiswa muchikamu chezvikamu zviviri, sezvinoratidzwa mumufananidzo 1. Welds kuruboshwe, bhoti kurudyi.Izvo simba rose re welds uye mabhoti rinogona kuverengerwa pano.Chikamu chimwe nechimwe chekubatanidza kwese chinoshanda chakazvimirira.Nokudaro, iyi code ndeyekusiyana kune nheyo iri muchikamu chekutanga che 2.6.3.
Mitemo ichangobva kukurukurwa inoshanda kuzvivako zvitsva.Kune zvivakwa zviripo, clause 8.3.7 D1.1 inotaura kuti kana zvimiro zvekuverenga zvichiratidza kuti rivet kana bhaudhi icharemerwa nemutoro mutsva, chete iripo static mutoro unofanirwa kupihwa kwairi.
Mitemo mimwecheteyo inoda kuti kana rivet kana bhaudhi ichingoremerwa nemitoro yakamira kana kutakurwa necyclic (kuneta) mitoro, simbi yakakwana uye welds inofanira kuwedzerwa kutsigira mutoro wakakwana.
Kugoverwa kwemutoro pakati pema mechanical fasteners uye welds kunogamuchirwa kana chimiro chacho chakaremerwa, nemamwe mazwi, kana kutsvedza kwakaitika pakati pezvinhu zvakabatana.Asi chete static mitoro inogona kuiswa pane mechanic fasteners.Rarama mitoro inogona kutungamira mukutsvedza kukuru inofanirwa kuchengetedzwa nekushandiswa kwemawelds anokwanisa kumirisana nemutoro wese.
Welds anofanirwa kushandiswa kutsungirira zvese zvakaiswa kana zvine simba kurodha.Kana ma mechanical fasteners atoremerwa, kugovaniswa kwemutoro hakubvumidzwe.Pasi pe cyclic kurodha, kugovaniswa kwemutoro hakubvumidzwe, sezvo mutoro unogona kutungamira mukutsvedza zvachose uye kuwandisa kweweld.
mufananidzo.Funga nezvejoini repamakumbo rakange rakasungwa zvakasimba (ona Mufananidzo 2).Chimiro chinowedzera simba rakawedzerwa, uye zvinongedzo uye zvinobatanidza zvinofanirwa kuwedzerwa kuti zvipe kaviri simba.Pamusoro pemuonde.3 inoratidza hurongwa hwekutanga hwekusimbisa zvinhu.Ko kubatana kunofanira kuitwa sei?
Sezvo simbi itsva yaifanira kubatanidzwa kune yekare simbi ne fillet welds, injiniya akasarudza kuwedzera mamwe fillet welds pajoinhi.Sezvo mabhoti akanga achiri panzvimbo, pfungwa yepakutanga yaiva yekuwedzera chete welds yaidiwa kuendesa simba rakawedzerwa kune simbi itsva, kutarisira 50% yemutoro kuti upinde nepakati pemabhoti uye 50% yemutoro kuti uende kuburikidza nemagetsi matsva.Zvinotenderwa here?
Ngatitangei kufunga kuti hapana static mitoro iri kushandiswa pakubatanidza.Muchiitiko ichi, ndima 2.6.3 yeAWS D1.1 inoshanda.
Mune ino yemhando yekubatanidza yemhando, iyo weld uye bhaudhi haigone kutariswa kugovera mutoro, saka iyo yakatsanangurwa weld saizi inofanira kunge yakakura zvakakwana kutsigira yese static uye ine simba mutoro.Kutakura masimba emabhoti mumuenzaniso uyu hakugone kuverengerwa, nekuti pasina static mutoro, iyo yekubatanidza ichava mune yakaderera mamiriro.Iyo weld (yakagadzirirwa kutakura hafu yemutoro) inotanga kuputika kana mutoro wakazara waiswa.Ipapo bhaudhi, rakagadzirirwawo kuendesa hafu yemutoro, rinoedza kuendesa mutoro uye kutyora.
Uyezve fungidzira kuti static load inoshandiswa.Mukuwedzera, zvinofungidzirwa kuti kubatana kuripo kwakakwana kutakura mutoro uripo unogara.Panyaya iyi, ndima 8.3.7 D1.1 inoshanda.New welds inongoda kumira yakawedzera static uye general live mitoro.Mitoro yakafa iripo inogona kupihwa kune iripo ma mechanical fasteners.
Pasi pemutoro wenguva dzose, kubatana hakuregi.Pane kudaro, mabhaudhi anototakura mutoro wawo.Pave nekutsvedza mukati memubatanidzwa.Naizvozvo, welds anogona kushandiswa uye anogona kufambisa mitoro ine simba.
Mhinduro kumubvunzo "Izvi zvinogamuchirwa here?"zvinoenderana nemamiriro ekutakura.Muchiitiko chekutanga, mukushayikwa kwemutoro wakadzikama, mhinduro ichava yakaipa.Pasi pemamiriro ezvinhu chaiwo echiitiko chechipiri, mhinduro ndihungu.
Nekuda kwekuti static load inoiswa, hazvigoneke nguva dzose kutora mhedziso.Chiyero chemitoro yakadzikama, kukwana kweiyo iripo mechanical connections, uye mamiriro ekupedzisira mitoro-ingave static kana cyclic-inogona kuchinja mhinduro.
Duane K. Miller, MD, PE, 22801 Saint Clair Ave., Cleveland, OH 44117-1199, Welding Technology Center Manager, Lincoln Electric Company, www.lincolnelectric.com.Lincoln Electric inogadzira midziyo yewelding uye welding zvinobatika pasi rese.Welding Technology Center mainjiniya uye matekinoroji anobatsira vatengi kugadzirisa matambudziko ekushongedza.
American Welding Society, 550 NW LeJeune Road, Miami, FL 33126-5671, foni 305-443-9353, fax 305-443-7559, website www.aws.org.
ASTM Intl., 100 Barr Harbour Drive, West Conshohocken, PA 19428-2959, phone 610-832-9585, fax 610-832-9555, website www.astm.org.
American Steel Structures Association, One E. Wacker Drive, Suite 3100, Chicago, IL 60601-2001, foni 312-670-2400, fax 312-670-5403, website www.aisc.org.
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