** Archival Expert Content:** Tsab xov xwm khaws cov piv txwv keeb kwm thiab cov lus thov ntawm welded steel girders, txuas hniav thiab trusses, tab sis tsis yog ib tug tsim, xam, sib koom specification, vuam txoj kev npaj, txheej txheem tsim nyog, qaug zog soj ntsuam los yog kho phau ntawv. Cov khoom siv, weldability, toughness, thickness, kev sib koom ua ke, cov khoom siv muab tub lim, preheat, ib ntus, residual stresses, tolerances, corrosion, hluav taws kub, qaug zog thiab tswj yuav tsum tau txiav txim siab raws li qhov project tshwj xeeb thiab cov qauv siv. Cov kabmob pob qij txha yog tsim, tua thiab tswj los ntawm cov neeg tsim nyog tsim nyog.
Hnub no, Savo Kusić tau tsom mus rau qhov rais ntoo, wood-aluminium Qhov rais, kev cai Qhov rais, qhov rooj thiab thov lus hais. Kab lus no tseem yog keeb kwm archive thiab tsis sawv cev rau kev tsim, vuam, sim lossis ntxiv dag zog rau cov qauv hlau.
Tag nrho cov welded brackets
ntu ntawm kev txhawb nqa
Ib qho kev piav qhia yog muab los ntawm fig.1thiab2. Sl.1thiab qhia txog kev txhawb nqa ntxiv nrog welded siv lamellas. Tshooj ntawm arbitrary load peev tuaj yeem sib sau los ntawm cov hlau dav hlau thiab cov ntawv hlau (daim duab.1b rau e). Ib qho qhib kev sib koom ua ke ntawm lub kaum sab xis yuav tsum zam los ntawm kev ua kom cov ntawv ntsug (fig.1c). Cov ntu ntu ntawm kev txhawb nqa tuaj yeem hloov kho mus rau lub sijhawm ua haujlwm uas yuav tsum tau muaj nrog ntxiv siv slats. Sections nyob rau hauv daim duab.2d rau f muaj qhov zoo tshaj plaws uas lub ntsej muag seam tuaj rau hauv thaj tsam ntawm qhov tuab ntawm cov tav. Ntawm no, cov seams tuaj yeem kuaj tau yooj yim tshwj xeeb nrog X-rays.
_ Daim duab1- ntu ntawm welded kev txhawb nqa._
_ Daim duab2- ntu ntawm kev txhawb nqa ua los ntawm cov profile tshwj xeeb._
** Weld tswj: ** kev kuaj hluav taws xob siv hluav taws xob ionizing thiab tsuas yog ua raws li kev tswj xyuas los ntawm cov kws tshaj lij. Kev xaiv ntawm txoj kev tswj hwm, thaj tsam ntawm kev lees paub thiab cov qauv zoo yog txiav txim siab los ntawm qhov project thiab tus qauv; Kev tshuaj xyuas ntawm daim duab lossis qhov chaw sab nraud tsis yog pov thawj ntawm qhov zoo ntawm qhov vuam.
Kev txuas ntxiv ntawm daim ntawv ntsug
Txoj kev loj hlob coj qhov chaw nyob rau hauv ib tug kiag li tsim nyog yam. Extensions nrog garters tau ua. Txoj kev txuas ntxiv ntawm lub qhov rooj tsis tau txais qhov tseem ceeb hauv kev tsim kho choj, tab sis nws tseem ua pov thawj tias qhov zoo hauv kev tsim vaj tsev. Txij li cov ntsug txuas ntxiv mus rau qhov sib txuas tsis zoo vim qhov kev cia siab me me, qhov txuas ntxiv nrog qhov ntev ntawm cov seam tau pom.
Universal extensions
Sl.3qhia tau hais tias qhov txuas ntxiv ntawm lub ntsiab girder ntawm txoj kev loj choj nrog ib tug reinforced tav. Sl.4muab qhov txuas ntxiv ntawm ib tus choj ntawm txoj kev loj. Ntawm nws qhov zoo tshaj plaws, qhov kev txuas ntxiv no tsis txawv ntawm qhov tsos thiab hom kev ua los ntawm kev txhawb nqa tsis txuas ntxiv, tsuas yog lub zog qaug zog qis dua me ntsis. Qhov kev daws teeb meem txuas ntxiv nyob ntawm seb nws puas yog kev cob qhia txuas ntxiv lossis kev sib dhos txuas ntxiv. Txij li cov cuab yeej zoo dua muaj nyob rau hauv kev cob qhia, vuam ntawm qhov chaw tsuas yog txwv yog tias ua tau. Sl.5qhia txog kev faib ntawm ib kab ntev63m. Cov girders raug xa mus rau qhov chaw tsim kho nyob rau hauv qhov chaw ntawm38mthiab25mntev, qhov twg tsuas yog cov extensions cim nrog “B” tau welded. Cov mounting extensions yog ua raws li U-extensions, thiaj li tsis txhob overhead vuam.
_ Daim duab3- txuas ntxiv ntawm tus choj girder ntawm txoj kev loj nyob ze Hattenheim._
_ Daim duab4- keeb kwm nthuav dav ntawm kev txuas ntxiv ntawm tus choj girder._
_ Daim duab5- lub sijhawm ntawm kev cob qhia thiab kev sib dhos txuas ntxiv._
Kev txhawb nqa tas li txuas ntxiv tau welded thaum lub sij hawm ua tiav ntawm kev sib dhos raws li qhov qhib tsis muaj scaffolding, piv txwv li. nyob ze ntawm txoj kev choj nrog qhib los ntawm42m. Qhov chaw ntawm kev txhawb nqa tau nruab nrog lub ntab crane thiab tom qab kev teeb tsa ntawm tag nrho cov ntsiab lus, lawv tau welded. Nyob rau tib lub sijhawm, cov kev txhawb nqa tseem ceeb tau txuas nrog screws siv garters nrog qhib (daim duab.6). Los ntawm lub qhov nyob rau hauv lub garters, feem ntau ntawm cov seam ntawm daim ntawv ntsug yuav tsum tau welded, ua ntej lub garters yuav tsum tau muab tshem tawm. Sl.6muaj cov ntaub ntawv ntxiv txog kev npaj ntawm U-seams rau tshwj xeeb profiles nyob rau hauv lub Upper thiab qis siv.
_ Daim duab6- ib ntus tourniquets nrog qhib rau vuam nkag._
** Kev teeb tsa thiab chaw ua haujlwm: ** keeb kwm piv txwv nrog ntab crane, lashings ib ntus, kev ua haujlwm hatch thiab qhov chaw vuam tsis yog kev npaj ua haujlwm. Kev suav ntawm cov xwm txheej ib ntus, kev tshem tawm thiab kev ruaj ntseg txoj kev npaj, geometry tswj, lub caij nplooj zeeg, tiv thaiv hluav taws thiab pa taws thiab traceable tswj ntawm txhua qhov sib koom ua ntej yuav tsum tau tshem tawm cov kev txhawb nqa ib ntus.
Stiffeners
Nws yog ib qho tsim nyog yuav tsum tau ua kom nruj cov khoom welded txhawb nqa zoo tiv thaiv lub protrusion ntawm daim ntawv ntsug thiab lateral buckling ntawm txoj siv sia, ntxiv rau, khoov thaum lub sij hawm vuam yuav tsum tau khaws cia nyob rau theem qis. Shrinkage stresses ntawm ntsug stiffeners tau tshawb xyuas los ntawm O. Graph-a. Thaum lub sij hawm soj ntsuam ib theem zuj zus ntawm tej hauj lwm (stiffeners tau welded ua ntej, ces lub ntsiab seams), loj shrinkage stresses tshwm sim nyob rau hauv lub stiffeners thiab nyob ze strips ntawm ntsug daim hlau. Yog hais tias cov stiffeners twb nyob rau ntawm txoj siv sia ua ntej lub ntsiab seams raug rub tawm, ces lub shrinkage ntawm txoj siv slats yog tiv thaiv. Nyob rau hauv txoj siv lamellas, wavy khoov nyob rau hauv lub longitudinal kev taw qhia2mm, nyob rau hauv lub transverse kev taw qhia approx0,25mm(fig.7). Yog li ntawd, yuav tsum muaj qhov tseem ceeb khoov kev nyuaj siab nyob rau hauv ob qho tib si cov lus qhia nyob rau hauv txoj siv slats. Cov kabmob muaj peev xwm raug txwv los ntawm qhov tshwm sim ntawm qhov loj deformations, tsis yog los ntawm kev tawg lub zog ntawm txoj siv hauv qab. Raws li cov txiaj ntsig ntawm qhov kev sim qaug zog, nws yuav tsum tau siv rau cov txuas hniav kom txhim kho cov phaj zoo ntawm cov stiffeners thiab siv, uas yog ruaj khov rau cov stiffeners nrog lub pob tw weld. Stiffeners thiab kev sib txuas raug txiav nyob rau hauv xws li ib txoj kev uas lub ntsiab seam tseem dawb (daim duab.8). Hauv kev lag luam hauv tsev, feem ntau, tsis muaj qhov tsis ntseeg tias cov stiffeners yog welded ncaj qha mus rau girders. Nws yog qhov zoo dua kom tsis txhob txiav cov seams thiab piling lawv ntau dhau.
_ Daim duab7- deformation ntawm txoj siv sia thaum vuam._
_ Daim duab8- stiffening nrog cov vuas zoo haum._
Shrinkage, deformation thiab qaug zog: cov txiaj ntsig kev xeem keeb kwm tsis tuaj yeem xa mus rau lwm qhov nthuav dav yam tsis muaj kev suav. Stiffeners, weld terminations, seam crossings, kam rau ua, thiab kev ua haujlwm ua ntu zus cuam tshuam rau qhov seem seem, buckling, thiab qaug zog; Cov kab nrib pleb thiab deformations tsis tuaj yeem daws tau los ntawm kev sib txuas ntxiv yam tsis muaj kev pom zoo kho.
Tag nrho mounts thiab thav duab
Arch txhawb nqa thiab arches slender
Arch braces muab qee yam tshwj xeeb me ntsis piv rau qhov tseeb tag nrho cov braces. Txawm li cas los xij, kev sib txuas ntawm ob-walled cantilever arches rau ib leeg-phab ntsa stiffening kab teeb, raws li tau ua nyob rau ntawm ob qhov loj tshaj plaws welded highway choj, yog ib qho ntawm cov kev nthuav dav tshaj plaws uas tau welded. Nyob rau ntawm txoj kev loj choj hla lub Lech ze Duisburg, ib tug loj machined piece ntawm forged hlau tau siv nyob rau hauv lub kawg node los pab txhawb kev vuam ua hauj lwm. Qhov no (Fig.9) siv lub zog los ntawm lub koov thiab hloov mus rau cov nqaj tawv. Nws yog nruab nrog50 mmnrog lub qhov hluav taws xob muaj zog, uas dhau los ntawm ib lub qhov mus rau sab sauv ntawm txoj siv tawv stiffening thiab uas yog welded rau daim ntawv ntsug, ntxiv dag zog rau lub thickness.50 mm.
_ Daim duab9- kawg ntawm tus choj arched._
Ncej tsim
Qhov zoo ntawm cov txheej txheem vuam yog qhov zoo tshaj plaws pom ntawm cov ces kaum ntawm lub thav duab, uas tso cai rau cov duab nyuaj ua yam tsis muaj teeb meem tshwj xeeb. Ib lub ces kaum ntawm tus ncej nrog ib tug hnyav load yog qhia nyob rau hauv daim duab.10. Kev tsim kho tau welded rhiav extensions. Cov mounting extensions yog txuas nrog tus kheej tapping screws. Thaum welding stiffeners ntawm ob txhais ceg ntawm kev txhawb nqa kev sib koom ua ke, kev ntxhov siab shrinkage siab tshwm sim, uas qee zaum ua rau tawg. Shrinkage stresses yog txo qis thaum es tsis txhob ntawm cov tav (daim duab.11a) navara tsuas tis nplooj ntawv (daim duab.11b).
_ Daim duab10- lub kaum sab xis ntawm tus ncej txhawb._
_ Daim duab11- sib piv ntawm welded kev twb kev txuas stiffening cov ntsiab lus._
_ Daim duab12- node ntawm ib tug Belgian choj nrog ncej girders._
Kev sib txuas ntawm kev txhawb nqa ntev yog nruj hauv kev khoov
Ib qho yooj yim yooj yim tuaj yeem ua tiav nyob rau hauv daim phiaj pavement ntawm txuas hniav los ntawm kev siv cov kev sib txuas welded. Kev qaug zog ntawm kev sib txuas ntawm kev txhawb nqa longitudinal, thiab lwm yam nyob rau hauv khoov load, nws yog illuminated los ntawm kev ntsuam xyuas O. Graph-a (Fig.13). Yog li ntawd, kev sib txuas nrog lub seam mus rau qhov sib txuas ntawm sab tensioned muaj lub zog qaug zog ntau dua ntawm qhov sib txawv ntawm kev ntxhov siab σUb dua li qhov kev sib txuas uas cov ceg tensioned txuas nrog lub kaum sab xis.
_ Daim duab13- keeb kwm sib txawv ntawm kev sib txuas ntawm kev txhawb nqa ntev._
Lattice txhawb nqa
Welded lattice structures
Cov gratings qub yog cov ntawv luam ntawm cov khoom siv riveted raws li cov duab thiab kev sib txuas (daim duab.14). Qhov no yog qhov tsis tsim nyog, cov khoom tshwj xeeb ntawm kev sib txuas welded yuav tsum raug coj mus rau hauv tus account thaum xaiv cov ntoo khaub lig. Qhov nruj dua ntawm txhua qhov kev sib txuas piv rau cov riveted nodes kuj tseem ceeb. Kev sib txuas ntawm kab pheeb ces kaum hauv cov kab ntawm kab sib chaws nrog ntau zog, tshwj xeeb tshaj yog nyob rau ntawm qhov chaw tsim kho, yog qhov nyuaj rau kev ua. Txij li thaum cov kev sib txuas nrog cov ces kaum seams tuaj rau hauv nqe lus nug ntawm no, lub zog qaug zog yog qhov tsawg. Siab welded, piv txwv li. thiab nyob rau hauv cov nodes ntawm welded kab sib chaws, yog li ntawd tsuas yog nyob rau hauv ib co tshwj xeeb cheeb tsam ntawm steel tsim. Piv txwv li, nrog lub ru tsev ties, nrog cranes tsis heev dynamically loaded, thiab lwm yam.
_ Daim duab14- welded node ntawm kev txhawb nqa lattice._
Hauv thawj qhov chaw, cov hlau tiaj tus thiab cov ntawv hlau tuaj rau hauv kev txiav txim siab rau kev tsim cov ntu ntu. Nyob rau hauv cov ntaub ntawv ntawm welded kev tsim kho, hollow seem yog ua tsis muaj teeb meem tshwj xeeb, uas muaj qhov zoo ntawm nias rods vim lawv torsional nruj. Cov ntaub ntawv tshwj xeeb ntawm ib puag ncig lub raj tsim nyog tshwj xeeb hais. Welded tubular kev tsim kho tau pom daim ntawv thov dav, piv txwv li. nyob rau hauv kev tsim kho ntawm cranes lossis teeb pom kev hauv kev lag luam hauv tsev. Nyob rau hauv cov ntaub ntawv ntawm kev txuas ntxiv thiab kev sib txuas ntawm hollow seem, ib qho yuav tsum tau coj mus rau hauv tus account qee yam kev tsim teeb meem thiab cov nqi ntxiv. Welded seem feem ntau sib sau ua ke ntawm qhov kawg kom qhov kev sib txuas tau yooj yim dua (daim duab 15). Cov kev ntsuas tshwj xeeb uas yuav tsum tau muaj nyob rau hauv lub rooj cob qhia thiab ntawm qhov chaw tsim kho rau welded lattice qauv ua rau nws nyuaj rau kev thov, tshwj tsis yog tias nws yog hais txog kev txhawb nqa nrog me ntsis lossis feem ntau zoo li qub. Rau dynamically loaded daim phiaj thiab rau cov neeg uas muaj siab rog, txoj cai yog hais tias tsuas yog ib tug neeg lub ntsiab yog welded, tab sis lawv kev sib raug zoo yog ua tiav siv screws. Ua ntej tshaj plaws, qhov teeb meem ntawm kev teeb tsa raug tshem tawm; thiab daim phiaj ua los ntawm cov khoom siv welded tuaj yeem ntsia tau raws li cov txheej txheem tib yam li cov riveted rods.
Daim duab 15 — shaping ntawm kawg ntawm lub hollow seem rau kev twb kev txuas.
Cov nplooj ntawv knotted, uas tau txais cov kab pheeb ces kaum tib lub sijhawm, yog riveted nyob rau hauv txoj kev niaj zaus mus rau tav ntawm txoj siv tawv los yog pob tw-welded nrog lawv (daim duab.16a). Cov tom kawg muaj qhov tsis zoo ntawm “pib ces kaum seams”, uas yog detrimental rau qaug zog lub zog ntawm lub girder. Ib qho kev txiav txim siab mus rau qhov tseeb shaping ntawm truss txuas hniav los ntawm vuam tau ua nyob rau ntawm lub railway choj hla lub Rhine ze Mainz (Kaiser Choj). Lawv nyob ntawd50 mmreinforced nodal nplooj ntawv los ntawm txoj kev ntawm seams ntawm lub interface tso rau hauv cov nplooj ntawv ntsug ntawm txoj siv sia30 mmtuab. Cov kev hloov yog gradual, lub shaping tuaj yeem pom los ntawm daim duab.16b. Extensions ntawm txoj siv rods yog nyob ib sab ntawm cov nodes.
_ Daim duab16- cov ntaub ntawv sib txuas ntawm qhov sib txuas tiv thaiv cua thiab tus choj kev tsheb ciav hlau hla Rhine ze Mainz (Kaiser tus choj,1954)._
Kev txhawb zog los ntawm vuam
Tom qab ntxiv dag zog rau cov qauv steel yog ib qho ntawm cov haujlwm nyuaj tshaj plaws, tshwj xeeb tshaj yog thaum nws yuav tsum tau ua ntawm cov qauv thauj khoom. Nrog rau kev sib txuas riveted, inserting reinforcements, drilling thiab txuas mus rau qhov uas twb muaj lawm yog lub sij hawm siv thiab kim. Txij li thaum vuam yog ua tau yam tsis muaj kev npaj ua ntej mus sij hawm ntev thiab tsis muaj kev rhuav tshem cov kev sib txuas uas twb muaj lawm, nws tau nyob ze rau sim vuam qhov kev txhawb zog ntawm cov ntu ntu thiab kev sib txuas ntawm cov kab sib chaws. Kev sib koom ua ke ntawm rivets thiab welds hauv kev txais lub zog hauv cov pas nrig tau raug tshuaj xyuas hauv kev nthuav dav theoretically thiab hauv kev sim. Txawm li cas los xij, hauv kev siv tswv yim, cov kab nrib pleb thiab qaug zog tshwm sim, ib nrab tsuas yog tom qab siv ntev. Qhov ua rau ntawm cov teeb meem no yog qhov cuam tshuam ntawm kev sib tsoo thiab kev hloov pauv sai sai ntawm ntu, thiab qee qhov ntawm cov kab nrib pleb uas tshwm sim los ntawm kev ntxhov siab los ntawm shrinkage.
** Kev ua kom muaj zog ntawm cov qauv uas twb muaj lawm: ** vuam ntawm kev ntxhov siab lossis cov laus hlau tuaj yeem qhia cov kab nrib pleb, tawg tawg, hauv zos poob ntawm kev ruaj ntseg thiab txoj kev quab yuam tshiab. Ua ntej ua haujlwm, cov khoom siv, kev puas tsuaj uas twb muaj lawm thiab qaug zog, qhov tseeb load, weldability, load relief sequence thiab kev pov hwm ib ntus yuav tsum tau txiav txim siab. Kev txhawb zog tsuas yog ua raws li qhov kev pom zoo thiab cov txheej txheem, nrog kev saib xyuas thiab kev tswj xyuas.
Ua ke vuam, riveting thiab screws
Rau qee lub sijhawm nws raug txwv tsis pub siv vuam thiab riveting ib txhij. Tshwj xeeb mloog yog them rau “tag nrho welded tsim” nyob rau hauv uas rivets thiab screws raug zam kiag li. Niaj hnub no, welding thiab riveting yog rov siv dua nyob rau hauv parallel ntawm tib yam khoom. Nyob rau hauv ntau zaus, nws yog tsim nyog los weld tsuas yog lub rhiav extensions, thiab ntawm qhov tsis tooj, mus rivet lub prefabricated sawv daws yuav. Daim ntawv thov ntawm ob hom kev sib txuas hauv tib qhov txuas ntxiv yuav tsum raug zam, vim tias qhov kev faib tawm meej ntawm lub zog tsis tuaj yeem ua tiav vim qhov shrinkage ntsig txog vuam thiab zawv zawg ntawm rivets / bolts.
** Daim ntawv kawg: ** kev sib koom ua ke ntawm welds, rivets thiab screws yuav tsum tsis txhob xav tias tsis muaj kev suav cov qauv, cov txheej txheem ntawm kev ua tiav, kev ua siab ntev thiab kev tswj xyuas. Rau txhua qhov kev nthuav dav ntawm kev thauj khoom, txoj kev quab yuam, pawg qaug zog, kev nkag mus rau vuam thiab kev soj ntsuam, kev siv tsis raug thiab cov phiaj xwm saib xyuas thoob plaws hauv lub neej ntawm cov qauv yuav tsum paub.