Ukuhlanganisa kubizwa izixhumanisi ezisebenzela ukunweba noma ukwandisa. Ukuhlanganisa, isb., kuyadingeka ngoba ubude noma ububanzi bamashidi agingqiwe abutholakali ngokwanele, ekufakweni kuyadingeka ngenxa yokukhawulela ubukhulu nesisindo sezinto ezithwalwayo ngabanye. Ama-podvezice abizwa amashidi avala ukuphazamiseka ekuhlanganiseni. Zonke ezinye izixhumanisi, ikakhulukazi lezo phakathi kwezinduku zama-truss ezinkomba ezahlukene nabathwali ezindizeni ezahlukene, zibizwa ngokuthi izixhumanisi.
Ekuhlanganiseni okujwayelekile amabhande okuqinisa nezikhonkwane zokuhlanganisa ziklanywa ngokwamandla aphelele. Ngakho-ke ekuhlanganiseni okujwayelekile akudingeki ukuthi izindawo zokuhlanganisa zithintane.
Indawo eyinhloko yokusetshenziswa kwezinduku ezidonswayo nezicindezelwayo (lezi yizinduku eziqondile, ezilayishwa ikakhulukazi ngamandla ajwayelekile) yizakhiwo rešetke. Izincazelo zalesi sigaba zishiya ngaphandle ingozi yokugoba kwezinduku ezicindezelwayo. Kuqala kuzocatshangelwa amandla esimo esimile.
Ukudonswa kwezimbobo ezindukwini ezisemandla okuqina
Umthamo wokuthwala: Isimo sengcindezi emthonjeni odonswayo siguqulwa kakhulu endaweni ngenxa yezimbobo/okuvuleka. Endaweni yobudlelwano obulinganayo, ukusatshalaliswa kwengcindezi esigabeni esibuthakathaka kuyahambisana (is. 1). Ingcindezi enkulu ye-longitudinal emthonjeni ongunxande ngokuka-A. Henning ithi:
maxσ = σm*[3-(d/b) + 0,8(d/b)2]
Sl. 1 - Izingcindezi ezinde nezinqamulelayo endukwini ebholiwe a) ngokusho kuka-A. Henning; b) ngokusho kuka-M. Rudeloff
Esimweni somkhawulo d/b = 0 samalamela abanzi kakhulu kulandela khona maxσ = 3σm futhi esimweni esiboniswe emfanekisweni 1a d/b = 1/3 kungu maxσ = 2,42 σm. Ngaphandle kwengcindezi yobude kukhona futhi izingcindezi eziphambene nezokugunda. Ukucindezeleka okukhulu kusezindongeni zomgodi. Lapho kuqala ukuvela ukuguquka okuhlala njalo, okungukuthi iziqongo zokucindezeleka ziyaphahlazeka bese kuvela ukulinganiswa kwengcindezi esigabeni. Ukuguquka okuhlala njalo okubonakalayo endaweni yemigodi kuqala kuphela lapho isilinganiso sokucindezeleka σm esigabeni esibuthakathaka seqa umkhawulo wokwelulwa σFO. Ukuguquka okuphelele kwenduku ku_SF = Fm * σF_ kuba kukhulu kancane kuphela kunalokho kwenduku engenazimbobo. (Fm iyindawo yesigaba esibuthakathaka)
Ekuhlolweni kokudonsa ngezinduku eziboshelwe ngama-rivethi, ukuphuka kuhlala kwenzeka ezigabeni ezibuthakathaka. Umthwalo ngesikhathi sokuphuka, ezimweni ezijwayelekile, utholakala ngokunembile ngokwanele SB = Fn * σB. Ukuhlolwa kokudabula ezindukwini ezicindezelwe ezinezimbobo ezivulekile kubonise izimo zokuphuka njengoba kukhonjisiwe ku- sl. 2.
Sl. 2 - Izithombe zokwephuka kwezinduku ezidonswayo
Ezivivinyweni zokuxhumana ezirivethwe kubonisiwe ukuthi izandiso ezinamabhande anomugqa owodwa wama-rivethi zinokumelana okuncane kunezandiso ezinokuningi imigqa yama-rivethi elandelanayo. Ngokwalokho ingcindezi emaphakathi ngesikhathi sokuphuka σB esigabeni esisebenzayo yayingu:
Inqubo yokubala osayizi bemigoqo edonswayo: Ngokwendlela ejwayelekile yokubala, ingcindezi emaphakathi yokudonsa kufanele ihlangabezane no-σm = S/Fm ≤ dozσ futhi lokho kuzo zonke izigaba ezibalulekile Fm. Ukwehliswa kwezimbobo kunqunywa esigabeni esiqondile esinenani elikhulu kakhulu lezimbobo, kanti kungenzeka ukuthi isigaba esiphukile esinezimbobo eziningi sinikeze inani elincane le-Fm (is. 2). Kulowo mqondo, kumaphrofayili agoqiwe i-Fm ibalwa ngokuvula. Ezindaweni eziyinkimbinkimbi kusetshenziswa wona lowo mqondo.
Isilinganiso Fm/F ngokuvamile siphakathi kuka 0,8 no 0,9, okusho ukuthi ukwehliswa okwenziwa yizimbobo ΔF = F – Fm kulingana no 10% kuya ku 20% yengxenye yonke F yenduku. Ezakhiweni ezinkulu i-ΔF ithinta kakhulu isisindo, ngakho-ke kufanelekile ukuthola izingxenye ezinokwehliswa okuncane kwezimbobo.
Ukuguquka: Ukunwebeka okunwebekayo kwemigoqo edonswayo enezimbobo akudluli kancane kakhulu kunokwemigoqo engenambobo efanayo. Ukunwebeka konke kwezinhlanganiso cishe kufana nokwezelwe kwama-lamellae aqhubekayo. Ngakho-ke kwanele ukuze kubalwe ukuguquka kwezakhiwo zensimbi ukunquma ukunwebeka okunwebekayo ngamavelu E no-F wemigoqo engancishisiwe. Ukuphepha ekugelezeni kukhulu emigqeni enokuncipha kunokwesibonelo emigqeni ecindezelweyo.
Ukusatshalaliswa kwamandla ezikhonkwaneni
Isith. 3
Ukusatshalaliswa kwamandla S ebhandeni kuya ezinhlelweni zokuxhuma ngama-rivethi ngamanye kuncike ezicini zawo zokuqina, futhi “akucacisiwe ngokwezibalo”. Esimweni sesl. 3 ukusatshalaliswa N1, N2, … kuncike ekuguqukeni kwama-rivethi namashidi axhunyiwe, kushintsha ngokwesilinganiso Fpodvezice/Fštapa. Uma Fpodvezice ≠ Fštapa amandla okugcina kuma-rivethi awasefanani kangako (sl. 50a). Ngokuncipha kwesilinganiso Fpodvezice/Fštapa kuba nguNn kuncane, N1 kusondela ku-S. Ukuhlanganisa ama-lamellae anogqinsi oluhluke kakhulu (sl. 4b) akufanelekile ngenxa yokulayishwa ngokweqile kwerivethi yokuqala.
Umfanekiso 4 - Umthwalo wama-rivet lapho Fštap > Fpodvezice
Ama-lamela kanye nama-tie rods aqinile, kuphela ama-riveti anwebekayo (is. 5a). Khona-ke wonke ama-riveti athola ukugoba okufanayo, wonke amandla ema-riveti kufanele alingane.
Ama-rivet aqinile, kanti ama-lamella neziphanyeko kuphela eziguqukayo (umfanekiso 5b). Njengoba ukunwebeka endukwini naseziphanyekweni phakathi kwe-rivet yokuqala neyokugcina kufanele kube okufanayo, kulandela ukuthi N2 = N3 = … = Nn-1 = 0, ngaphandle kwe-N1 = S * x1.
Umfanekiso. 5
Ukusatshalaliswa kwangempela kwamandla kulele phakathi kwalezi zimo zemingcele. Uma umthwalo ukhula, kuqala kuvele ukuguquka okungunaphakade kuma-rivethi asemikhawulweni, ama-rivethi athwele umthwalo omkhulu ayakhululeka futhi ukusatshalaliswa kwamandla kuba ngokulinganayo ngokwengeziwe. Ngemva kokuvela kokuguquka okukhulu, ukusatshalaliswa kwamandla kusondela esimweni lapho ama-lamellae namabhandi okubopha kuqinile, okungukuthi, amandla kuma-rivethi cishe ayalingana, uma ukusika kwama-rivethi kuyisici esinqumayo.
Umthwalo ekwehlulekeni: Indlela yokubethela izikhonkwane inomthelela omncane kakhulu ku-τBV. Amandla okushelela e-τBV esixhumi cishe azimele enanini lezikhonkwane, ukuhlelwa kwazo, nokuma kwesixhumi esibethelwe; umthwalo ekwehlulekeni uhambisana, ngokusondele kakhulu, nomthwalo olinganayo kuzo zonke izikhonkwane. Izitatimende ezifanayo ziyasebenza nakumajoyinti avamile anezikulufu, okuvela kukho kungaphethwa ukuthi ukumelana nokushelela akunamthelela obalulekile emandleni okuthwala.
Ukubalwa kosayizi: Ezakhiweni zensimbi nasezinduku ezithwala umthwalo phakathi nendawo kubalwa ngokwabiwa okufanayo, okungukuthi, nge-rivethi ngayinye N = S/n. Njengoba emisebenzini emide ama-rivethi okuqala esegcwala umthwalo ngokweqile kusenesikhathi, kunconywa ukugwema, uma kungenzeka, ukuba kube nezigaxa ezingaphezu kuka-6 zama-rivethi zilandelana.
Ukumelana nokushelela: Ukushelela ezihlanganisweni kuvela kakade ngisho nasemthwalweni omncane uma kuqhathaniswa. Ukumelana nokushelela kuncike ikakhulukazi emandleni okuqinisa, aguquguquka ngenxa yezinto eziningi. Lokhu kushiywa ngaphandle lapho kuklanywa izixhumanisi ngama-rivet nangezikulufo ezazivame ukusetshenziswa kuze kube manje. Kukhonjwa izixhumanisi ezinezikulufo ezisezingeni eliphezulu.
Ukusatshalaliswa kwamandla ezinsikeni ngokobubanzi: Uma izikhala phakathi kwezinzipho zilingana futhi ziqondene nohlangothi lwamandla (sl. 6a), izinsikeni ngazinye ziba nemichilo yobubanzi obulinganayo a besiphambano, ngakho-ke ekuqageleni kokuqala amandla ezinsikeni N = a t σ ayalingana. Ukusatshalaliswa ezimeni zezikhala ezingalingani phakathi kwezinzipho akuchazeki ngokwezibalo; esimweni esiku sl. 6b kwenzeka ngokomthetho welevers.
Fig. 6
Induku edonswayo
Ukuqhubeka: Ukuqhubeka ngezibopho ezilinganayo (sl. 3 no 4). Amandla S endukwini endaweni yokuhlanganisa kumele athwalwe yisibopho kuphela. Ama-rivet kulokhu kuqhubeka kufanele futhi aklanywe ngokohlelo lwe-S, ngoba kufanele adlulise wonke amandla asuka endukwini eqhubekayo aye ezibophweni.
Amaphiko anokusekela okuhlangothi olulodwa axhunywe nezingcindezi ezengeziwe ezinkulu zokugoba emafetheni axhunyiwe, ezisekelweni nasezikhonkwaneni. Ukumbozwa kohlangothi olulodwa kwezingxenye zokwengeza kusetshenziswa ngenxa yokuguquka okukhulu kuphela lapho (sl. 7) lapho induku iqinile ekugobeni noma lapho ibanjwe eceleni ngendlela engakwazi ukugoba.
Umfan. 7
Ukuxhumana okungaqondile – Uma amabhande okuhlanganisa engakwazi ukulala ngokuqondile emaqenjini aqhubekayo, ama-rivethi namashidi athola izingcindezi zokugoba ezinkulu kakhulu. Ngakho-ke, ngokwenani m lezendlalelo, kukhethwa inani elikhulu n’ lama-rivet kunenani n ekumbozweni okuqondile kokuhlanganisa.
Umdwebo 8
Ezimingeni eziyinkimbinkimbi kuhlelwa amabhande okubopha ukuze kugwenywe ukukhuphuka kwendawo kwengcindezi, ngakho izindawo ezingazodwana zamabhande okubopha zinqunywa ngokuvumelana nendawo yengxenye yemingeni abayimbozayo, ngokukhetheka kugcinwe indawo yesikhungo sesisindo. Ukusabalala kwezindawo zamabhande okubopha okuphambuka kulokhu kuhlotshaniswa nezinguquko ekusabalaleni kwengcindezi. Ku-fig. 9 kuboniswe ukuqhubekela phambili kwenduku enodonga olulodwa, ku-fig. 10 induku enezingxenye ezimbili ene-4 amapuleti aqondile kanye nobuso obubodwa phakathi kwama-engeli.
Isith. 9
Fig. 10
Uxhumano: Ezixhumanisweni zezingxenye ezidonswayo zisebenza ngokuyisisekelo izimpawu ezifanayo njengasekuqhubekiseni. Izivivinyo ziye zakhombisa inzuzo enkulu yokungeniswa kwamandla ngokulinganayo. Endabeni yokuxhumana ohlangothini olulodwa, kutholakala ukugobeka okukhulu ngobude nangobubanzi (sl. 11). Naphezu kwama-stress agobayo angeziwe amakhulu, izinduku ze-L ne-C ezixhunywe ohlangothini olulodwa zingasetshenziswa cishe ngokuphelele. Umthamo wokuthwala womxhumanisi oyedwa ungawela ube uhhafu uma kungathathwa zinyathelo zokulinganisa ama-moment agobayo angeziwe.
Umdwebo 11
Ukuze kuvalwe izengezo akumele kusetshenziswe ama-plate e-node, ngenxa yalokho kufanele kubhekwe ama-podvezica akhethekile. Ukuxhumeka kwi-node plate kuyasizwa uma ingxenye enkulu yesigaba senduku iwela endizeni ye-node plate.
Isith. 12 - Izixhumi ezine nangaphandle kwe-engela yokuxhuma
Induku ecindezelwe
Ngokuqhubeka nokuxhuma izinduku ezicindezelweyo kusebenze izimiso ezifanayo nezasezindukwini ezidonswayo, kanti nakuzo amandla aphelele adluliselwa ngamakhivikhivhi namaqoqo okubopha, okusho ukuthi, ngokwesigaba esigcwele F senduku kulinganiswa Fpodvezica no Fs, noma Fl. Ngokuvamile izindawo zokuqhubeka azihlanganiswanga ngokufanele. Ezindlini ezakhiwe ngensimbi, emibhoshongweni edlula ezitezi eziningi, ezithwala umthwalo wokucindezelwa kuphela, kusetshenziswa ithuba lokudlula ngokumbozwa kwezindawo zokuqhubeka okungagcwele kakhulu. Amandla okuthwala ezinduku ezicindezelweyo ayaphela, uma izimo zokungazinzi zingakaveli ngaphambili, sekudlula umkhawulo wokuthamba ngoba khona-ke kuvela ukuguquka okukhulu futhi induku igoba eceleni. Imigodi egcwele ama-rivets ayinawo umthelela ongabonakala ekuziphatheni kwenduku.
Amandla ekukhathaleni kwezixhumo ezinamabhawodi
Ngokuqina kokukhathala kokuxhumana okunamabhawodi, ikakhulukazi kunqunywa iziqongo zokucindezeleka ezivelayo emigodini. Ukuqina kokukhathala kuncishiswa kakhulu ngisho yizingodi ngokwazo. Izinti ezinemigodi evulekile ziyaqhekeka ezivivinyweni zokukhathala ngaphansi kokunwebeka ezigabeni ezibuthakathaka, futhi ukuphuka kokukhathala kuqala ngemifantu emaphethelweni omgodi, eqhubeka yeluleka ngesigaba. Ngakho-ke, imigodi ebushelelezi ibaluleke kakhulu. Ku-sl. 13 kunikezwe ukuqina kokukhathala kwezinti eziyisicaba ezigabeni ezihlukene (ngakwesokudla kukhona isigaba sensimbi esiphezulu). Ekulayishweni kwangaphambili okukhulu σu womabili la mathuluzi anokukhathala okuqinile σDz ngaphezu komkhawulo wokuvuna. I-amplitude yokucindezeleka icishe ifane kuzo zombili izigaba.
Sl. 13 - Amandla okuqhubeka nokukhathala σDz
Ekuhambeni kokulayishwa okushintshanayo kokudonsa nokucindezela kokuxhuma okuphonsiwe, empeleni kusebenza ubudlelwano obufanayo njengasemithwalweni enendlela eyodwa. Kuyafaneleka ukuqaphela ukuthi i-amplitude yokucindezeleka ngaphansi kokulayishwa okushintshanayo inkulu cishe izikhathi 1,5 (sl. 14), kodwa ama-rivets ngaphansi kwalokhu kulayishwa asengozini kakhulu kunangaphansi kokulayishwa okunendlela eyodwa.
Umfanekiso. 14 - Amandla okukhathala ekudonseni ezixhumanisweni ezinamabhawodi