Ukucindezeleka okujwayelekile kumabha aqondile namabha anokugoba okuncane
Incazelo yamandla okusika esigabeni
Ake kube khona induku eqondile elayishwa ngamandla anomkhombandlela ongahleliwe, okucatshangwa kuphela ukuthi wonke alele endizeni eyodwa (indiza yamandla) edlula emgqeni we-induku (umugqa ohlanganisa izikhungo zamandla zezigaba ezinqamulelayo).
Umd. 1
Ukuze kubalwe izingcindezi ezisebenza esigabeni esithile esinqamulayo n – n (umz. 1), kudingeka kwaziwe amandla adluliselwa ngalesi sigaba ukusuka engxenyeni eyodwa yenduku kuya kwenye. Ngokusobala, ngosayizi nendawo akulingana nerisitho lawo wonke amandla ahlasela ingxenye eyodwa yenduku. Leli risitho lihlakazwa libe izingxenye ohlelweni lwezixhumanisi lapho i-eksisi x ihambisana ne-eksisi yenduku, kanti i-eksisi z iwumugqa lapho indiza yesigaba esinqamulayo isika khona indiza yamandla. Ingxenye eqondiswe ku-eksisi z ibizwa ngokuthi amandla awela ngapha nangapha Q noma Qz futhi, egebeleni elilula, ithathwa njengelihle uma ngakwesobunxele sesigaba liya phezulu, kanti ngakwesokudla liya phansi.
Uma induku igobile, ama-axis wokuxhumanisa x no z anendawo ehlukile kuzo zonke izigaba ezinqamulelayo, futhi njalo kunjalo ukuthi i-x-axis iyithanji emgqeni we-induku. Uma indiza lapho ilele khona i-axis ye-induku ingahambisani nendiza yamandla, noma uma i-axis ye-induku iyijika lasemkhathini, isamba samandla esingakwesobunxele kwesigaba sinengxenye yesithathu futhi, amandla anqamulelayo Qy. Nge-N, Qz no Qy kunqunywa ubukhulu nendlela yamandla adluliselwa ngesigaba, kodwa hhayi indawo yawo. Kulokhu kudingeka futhi kwaziwe namamomenti awo maqondana nama-axis wokuxhumanisa. Esimweni sokugoba okuyisicaba kwanele ukwazi i-moment yokugoba M noma My. Esimweni esijwayelekile kakhulu kuvela omunye umoment wokugoba Mz kanye nomoment ozungeze i-x-axis, Mx.
Amandla ayisithupha kanye nama-moment achazwe engxenyeni edlule ahlanganiswa ngaphansi kwegama elivamile elithi „presečne sile“. Ukunqunywa kwawo kungomunye wemisebenzi eyisisekelo ye-statics yezakhiwo zokwakha.
Phakathi komthwalo osatshalaliswa ngokuqhubekayo p (ubukhulu: amandla ngeyunithi yobude), amandla e-transverse Q kanye nomzuzu wokugoba M kukhona, esimweni sokugoba okuyisicaba, ubudlelwano obulula. Okungukuthi, kusukela ezimweni zokulingana zento eyodwa yebhande (sl. 2) kutholakala
dQ + p dx = 0,
dM = Q dx;
ngakho-ke
Q = dM/dx,
p = - dQ/dx = - d2M/dx2. (1a, b)
Fig. 2
Ukusatshalaliswa kwezingcindezi ezijwayelekile
Uma induku icindezelwe kuphela ngamandla e-axial, esigabeni kuvela kuphela ukucindezeleka okuvamile okusatshalaliswe ngokulinganayo σ (induku eqinile yokudonswa, noma yokucindezelwa). Uma kuvela khona lapho nomzuzu wokugoba, la mazinga kumele asatshalaliswe ngokungalingani ngandlela-thile, ukuze isamba sawo singabe sisadlula phakathi nesikhungo sesigaba. Ukuze kunqunywe lokhu kusatshalaliswa, ithiyori yobunjiniyela bokugoba ayisuki esixazululweni esiqinile sezibalo eziyisisekelo, kodwa ithatha indawo yengxenye yalezi zibalo ngokuqagela okunengqondo okuthi esimweni esisodwa esilula kakhulu nakho kugcwaliseka ngokuqinile. Lesi simo esikhethekile ukugoba kwenduku ye-prismatic eqondile ngaphandle kokusebenza kwamandla aqondene nendawo eguqukayo (sl. 3). Zonke izingxenye zenduku ezikude ngokwanele emikhawulweni yayo zithola ukukhubazeka okufanayo, okuholela ngokuqondile ekutheni i-eksisi yenduku ibe yisiyingi, futhi wonke amafulethi ezigaba ezinqamulelayo ebeqale ebheke ngqo ku-eksisi yenduku ngesikhathi sokuguquka ahlale eyisicaba, ngoba ngalinye lawo liyifulethi lokulinganisa lezingxenye eziseduze zenduku eguqukile. Ngokwemvelo kuvela ukuqagela ukuthi izigaba ezinqamulelayo zihlale cishe ziyisicaba nalapho umzuzu wokugoba nesigaba esinqamulelayo senduku kungasagcini ngokufana, kodwa kushintsha kancane kancane ngobude benduku. Lokhu kuqagela okubizwa ngokuthi i-hypothesis ka-Navier kuyisisekelo sethiyori yokugoba.
Isith. 3
Ubukhulu bezingcindezi ezivamile
Uma into eqondile yebhimu igotshwa, ingxenye eyodwa ‘yezintambo’ zayo, okungukuthi imigqa yento ehambisana ne-eksisi yenduku, iyelulwa, kanti enye ingxenye iyafushaniswa (umf. 4). Phakathi kwalezi zingxenye ezimbili kunezintambo ezingathathi hlangothi z=0, ubude bazo obungashintshi lapho kugotshwa. Ake kube yiradiyasi yokugoba yalezi zintambo esimweni esigobile ϱ futhi mayibe ilele endaweni ye-x-z. Kusukela kumf. 4 m kungafundwa
Δ dx/z = _dx/_ϱ
futhi kusuka lapho kubalwe ukwelulwa kwemicu ebangeni z ukusuka ku-eksisi emaphakathi, elilingana
ε = Δ dx/dx = _z/_ϱ
ngakho-ke ngokususelwa emthethweni ka Hooke kukhona ukucindezeleka
σ _= Ez/_ϱ (2)
Umfanekiso 4
Lokhu kushubana kulingana nebanga ukusuka emicu engathathi hlangothi. Umphumela onjalo uxhumene nokuqagela ukuthi ngaphambi kokuguquka yonke imicu yengxenye yebhadi yayilinganayo ngobude, ukuze ibhadi ekuqaleni laliyisiqondile, noma okungenani lalinokugoba okuncane kangangokuthi umphumela wokugoba wawunganakwa. Umugqa lapho ungqimba olungathathi hlangothi kanye nendiza yesigaba kuhlangana khona ubizwa ngokuthi i-eksisi engathathi hlangothi. Siyamukela njengomumo we-y-eksisi (sl. 5). Isimo se-eksisi engathathi hlangothi esigabeni esiphambene sitholakala esimweni sokulingana kwamandla ngaku-x-eksisi: uma amandla ajwayelekile N=0 (ukugoba ngaphandle kwamandla ajwayelekile), khona-ke iresultanti yamandla angaphakathi echazwe ngezinga lokucindezeleka okujwayelekile esigabeni kumele ibe nguziro:
I-integral ohlangothini lwesokudla ingumzuzu we-static wendawo maqondana ne-eksisi y-. Ukuze ube nguziro, le eksisi kufanele ibe enye yezinhliziyo-eksisi.
Umzuzu M obangela ukuguquka unemiphumela maqondana nama-eksisi y no-z endizeni yesigaba esinqamulayo (umz. 5):
Isib. (3)
lapho Iy, Iyz kungamomenti wokungena wokulinganisa nowe-centrifugal wesigaba maqondana nezimbazo ezikhonjisiwe.
Icala elikhethekile elibaluleke kakhulu yilapho Mz=0. Leli cala livela lapho Iyz=0, okungukuthi lapho y no z kuyizinsika eziyinhloko zokungasebenzi komkhakha. Lokhu kusho ukuthi indiza yokugoba eyamukelwe lapha ihlangana nendiza x-z, kanye nendiza lapho kusebenza khona umzuzu wokugoba M=My, okungukuthi, nendiza yamandla.
Umfanekiso. 5
Uma kususwa _E/_ϱ ezilinganisini (2) nezili (3), kutholakala iphethini yokunquma ukucindezeleka lapho kugobeka ngokulinganayo (Iy=I):
σ = M/I * z (4)
kumaphuzu onqenqema 1 no-2 ngokukhethekile kuyi:
σ1 = M/I * h1 = M/W1, σ2 = - M/I * h2 = - M/W2. (5)
Ubukhulu W1,2 = I/h1,2 (ubukhulu: ubude okwesithathu) zibizwa ngokuthi ama-moment okumelana. Uma i-eksisi ephakeme ye-centroid nayo iyisizinda sokulingana kwesigaba, khona-ke W1 = W2, ngakho izingcindezi ezisemkhawulweni ziyalingana ngokwenani eliphelele.
Umugqa onwebekayo
Fig. 6
Ukubaluleka kwamaphethini ashiwo ngenhla kuxhumene nomthetho kaHooke. Lokhu kudinga ukuthi σ << E, ngakho-ke ngokwe (2) h << ϱ. Nokho ukugoba kungavunyelwa kube kukhulu kangangokuthi ϱ ibe ngobukhulu obufanayo nobude benduku l. Ezinhlakeni ezigobile ezicatshangelwayo ekwakhiweni lesi simo asenzeki; njalo ϱ inkulu kakhulu kune-l futhi ngenxa yalokho ukugoba w << l (fig. 6). Khona-ke ngokulinganiselwa kuyasebenza:
1/ ϱ = - d2w/dx2 = -w’’
nakusekelwe ku (3):
w’’ = - M/EI.
Lesi sibalo kanye nesimo sokulingana (1b) kwakha uhlelo lwezibalo ezihlukile zensika egobile. Ngokuzisusa zingancishiselwa esibalweni esisodwa sezinga lesine:
wIV = + p/EI
noma, uma kwenzeka ukuthi umzuzu we-inertia uyaguquguquka:
(EIw’’)’’ = +p.
Ngokuzihlanganisa kungatholakala umumo womugqa olastiki uma kunikezwa umthwalo p=p(x) futhi uma kuzo zonke izimo zenduku kwaziwa imibandela emibili yomngcele. Kule mibandela okungenani emibili kufanele ibe mayelana nokuguquka. Ngemininingwane bheka isihloko Statika građevinskih konstrukcija.
Inhliziyo yesigaba esinqamulayo
Uma i-eksisi engathathi hlangothi inqamula isigaba esiphambanweni, iyahlukanisa ibe yindawo yokunwebeka kanye nendawo yokucindezeleka. Ezintweni ezinokuqina okuphansi ekunwebekeni kuphakama umbuzo wokuthi amandla okucindezela kufanele asebenze kuphi, uma esigabeni esiphambanweni kungafanele kube khona ukunwebeka noma kuphi. Indawo yephuzu lokusebenza kwamandla ngaleyo ndlela ibekelwe indawo ebizwa ngokuthi umgogodla wesigaba. Umngcele womgogodla ngokusobala uyindawo yejometri yamaphoyinti, ama-eksisi awo angathathi hlangothi athinta isigaba esiphambanweni emaphethelweni aso. Ngalokhu kunikezwe futhi ukwakheka kwawo.
Ibanga lomngcele wenhliziyo ukusuka esikhungwini sesisindo, elikaliwe kunoma iyiphi indlela, sizolibeka ngo-k enenkomba ehambisana naleyo ndlela. Ngamachibi amakhulu e-inertia ngokwe-equation
σ = N/F + Mz/Iz y + My/Iy z (6)
imigomo imi kanje:
ky = i2z / ey, kz = i2y / ez. (7)
Ngomqansa oyindilinga onobubanzi beradiyasi r ibanga lomgogodla lingu k = r/4, kanti eringini eliyindilinga (amarediyasi: elingaphandle R, elingaphakathi r) k = (R2 + r2) / 4R.
Kunxande (sl. 7) ky = 1/6 b, kz = 1/6 h. Ngakho-ke, lapho umthwalo usebenza esigabeni esingunxande kwenye yezindiza zokulinganisa (kodwa kuphela lapho), kwanele ukuba umphumela usebenze engxenyeni yesithathu emaphakathi yobude noma ububanzi besigaba esinqamulelayo, ukuze izingcindezi esigabeni zibe nophawu olufanayo.
Umfan. 7
Savijanje u plastičnom području
Uma umkhawulo wokugeleza usufinyelelwe emicu eseceleni yenduku egobile, umthamo wayo wokuthwala awukapheli ngalokho, ngoba njengoba imicu yangaphandle iguquka ngokweplastiki ngaphansi kwengcindezi engaguquki, ezingxenyeni eziseduze kakhulu ne-eksisi engathathi hlangothi, lapho umkhawulo wokugeleza ungakafinyelelwa khona, ingcindezi iyanda, ngaleyo ndlela inyuke nomzuzwana wokugoba ongathwalwa yisigaba.
Uma kwaziwa kahle ukuhamba komdwebo wengcindezi nokuguquguquka, inqubo ezigabeni ezinomumo ophindwe kabili ngokulinganayo (ukuphakama h) ingalandelwa kalula ngokubala ngaleyo ndlela ukuthi, ngokucabangela ukuthi izigaba zihlala ziyisicaba, kusukela emdwebeni wengcindezi nokuguquguquka kutholwe ukusatshalaliswa kwengcindezi σ ngenxa yokugoba okuhambisana nokwelulwa okuthile okuvunyelwene ngakho kwemicu yokugcina ε__r futhi kusukela lapho, ngokuhlanganisa, kutholwe i-moment yokugoba. Uma lokhu kwenziwa ngezilinganiso ezihlukahlukene ze-ε__r futhi ngakolunye uhlangothi kubalwe ijika elihambisanayo lomugqa wokugoba w’’ = 2 ε__r / h, kutholakala uchungechunge lwamaphuzu lapho kungadonswa umugqa onikeza ukuxhumana phakathi kwe-moment yokugoba nejika M = M(w’’); lokhu kuxhumana akusalingani ngqo, futhi uma sekuyaziwa kungenzeka ngokuhlanganisa ngokomfanekiso ukunquma umugqa wokugoba ohambisana nokusatshalaliswa okunikeziwe kwamamoment. Uma isigaba singalingani, ukubala kuba nzima kakhulu, ngokuthi ku-ε__r ngayinye kusafanele futhi kunqunywe indawo ye-eksisi engathathi hlangothi.
Umdwebo 8
Ukubalwa kwenza kube lula ngokwezinga elithile uma, ngaphandle kokuthathwa kokulingana kwesigaba, kucatshangwa nokuxhumana okwenziwe lula phakathi kwengcindezi nokwelula ngokomfanekiso 8. Khona-ke izingcindezi ngenxa yokugoba, ngemva kokudlula umkhawulo wokugeleza, ziba nokusabalala okuboniswe emfanekisweni 9 futhi i-moment yokugoba iyi:
ngakho-ke ukugobeka komugqa wokugoba kutholakala lapho isibalo (2) sisetshenziswa engxenyeni yesigaba izingcindezi zayo ezisendaweni ye-elastic w’’ = σf / Ez’. Uma ukuma kwesigaba kwaziwa kuzo zonke z’ ezamukelwe, ama-integral angabalwa. Isb. endabeni elula kakhulu yesigaba esiphambanweni esingunxande esinobubanzi b nokuphakama h kuyi
Uma lapha z’ ivezwa ngosizo w’’, kutholakala
Ekuhlanganeni kwe-I-section nakwezinye ezifanayo, ukuhamba kwejika M-w’’ endaweni yepulasitiki kuba maningi kakhulu kuthi i-moment lapho kuqala khona ukugeleza icishe ilingane ne-moment enkulu yokugoba iseksheni engakwazi ukuyithwala nhlobo. Ngakho-ke ukubaluleka kokugoba kwepulasitiki ekwakheni akukhona ekwandiseni i-moment yokugoba iseksheni engayithwala, kodwa kusekutheni ukuguquka okukhulu kwendawo okuvela emkhawulweni wokugeleza kungaholela ekushintsheni okuhle kokusabalalisa kwamandla ezinhlelweni ezinganqunywanga ngokwezibalo.
Umfanekiso 9
Lokhu kungachazwa ngesibonelo sesekelo eliqhubekayo elinemikhakha emibili. Ake isekelo (sl. 10) libe nemikhakha yobude obulinganayo, i-cross-section engashintshi futhi ake lilayishwe ngomthwalo ohlukaniswe ngokulinganayo. Khona-ke ngaphambi kokufinyelela umkhawulo wokuthamba i-moment phezu kwesekelo MB = _pl_2/8. Uma umthwalo p ukhushulwa kangangokuthi i-moment esigabeni sesekelo ifinyelela inani Mf lapho kuqala khona ukuthamba, ngokukhuphuka okwengeziwe komthwalo kuleyo ndawo kuzokhula nokugobeka ngaphandle kokwanda okubonakalayo kwe-moment. Kwakheka okuthiwa i-plastični zglob, okungukuthi isekelo ngaphansi komthwalo owengeziwe siziphatha sengathi phezu kwesekelo esimaphakathi kukhona i-hinge. Umthwalo ungakhushulwa futhi kuze kube yilapho nasendaweni ye-moment enkulu emkhakheni kuqala ukuthamba. Ukukhushulwa okwengeziwe kwe-moment yokugoba akusakwazi futhi amandla okuthwala esekelo aphelelwe. Umthwalo lapho kuvela khona lesi simo ubizwa ngokuthi umthwalo womkhawulo.
Fig. 10
Ngokuvamile kungalindeleka ukuthi ohlelweni olulodwa olunezinqumo ezimile ezingaziwa n kufanele kuvele ama-hinge epulasitiki (n+1) ngaphambi kokuba uhlelo lube nokunyakazeka futhi ngaleyo ndlela lufinyelele umkhawulo walo wokuthwala umthwalo. Nokho, lo mthetho unokwahlukile kuzo zombili izinhlangothi. Njengoba isibonelo esishiwo sibonisa, emkhawulweni wokuthwala umthwalo kungavela ngesikhathi esisodwa ama-hinge amabili amasha epulasitiki (ezinkampanini zombili), ukuze uhlelo ebelusenganyakazi kuze kube khona luguquke ngokuzumayo lube uhlelo olunamadigri amabili enkululeko. Ngakolunye uhlangothi kungenzeka ukuthi ngisho nangaphansi kwe-(n+1) ama-hinge epulasitiki umthwalo usuphelile endaweni ethile, isib. uma kugatsha olulodwa kuphela kubhuloho eliqhubekayo luyavumela. Fig. 11 libonisa ukuthi lokhu kungenzeka kanjani ohlelweni olulodwa olunezinqumo ezimile ezingaziwa kabili olune n=2 ama-hinge epulasitiki. Uma ohlangothini lwesokudla lwebhuloho kwengezwa nesigaba sesine, ibhuloho liba ngokwezinqumo ezimile kathathu lingaziwa, ngakho kwanele ama-hinge epulasitiki (n-1) ukuze isigaba sokunxele sodwa sifinyelelwe emkhawulweni wokuthwala umthwalo.
Umdwebo 11
Amandla okushelela lapho kugotshwa
Ukubala okuyisisekelo
Fig. 12
Ukucindezeleka okujwayelekile σ, okungukuthi ukucindezeleka okuvela empeleni ngenxa yokugoba akusona sodwa ukucindezeleka endukwini egobile, kodwa kanye nakho kuvela nokucindezeleka kokugunda ngenxa yomthelela wamandla atraverse. Njengoba isici esiyinhloko sethiyori yobunjiniyela bokugoba kuwukuthi ukuguquka okubangelwa ukucindezeleka kokugunda akunakwa, lokhu kunganqunywa kuphela esimweni sokulingana. Ukuze lokhu kumiswe, ingxenye yebhimu dx iyasikwa, njengoba kuboniswe ku-sl. 12, ngendiza eqondile ibe izingxenye ezimbili, bese kumiswa isimo sokulingana samandla avundlile asebenza engxenyeni engezansi. Ngakwesobunxele lawa ngamandla angaphakathi avezwe yizicindezelo σ ngenxa yokugoba, okufanele kuhlanganiswe kusukela ku- z’ = z kuya ku- z’ = h2
Ohlangothini lwesokudla kusebenza izingcindezi ezifanayo, kodwa ezikhulisiwe nge-differential ngokuvumelana nomzuzu wokugoba ofanele M + dM. Umehluko phakathi kwamandla ezinhlangothini zombili zento kufanele ube sebhalansini namandla abangelwa izingcindezi zokugunda τ ezisebenza endaweni yokusikwa evundlile t dx:
Lapha i-integral imele umzuzu omile wengxenye yesigaba esiphambene ehlukaniswe indiza ephambene evundlile maqondana ne-eksisi yesikhungo sesigaba. Iphawulwa ngo S. Kusukela ku dM/dx = Q ngaphansi kwesimo sokulingana kutholakala:
τ = QS/It. (8)
Ngokombono wokuhlangana kwezingcindezi zokusika, lokhu ngesikhathi esifanayo kuwubukhulu bokucindezeleka okuqondile kokusika okusebenza endaweni yesigaba esinqamulelayo futhi okuthi, kanye no-S kanye no-t, kube umsebenzi ka-z.
Fig. 13
Umf. 13.1
Isibalo (8) sinikeza imininingwane ethembekile kuzo zonke izigaba ezinezindonga ezincane uma indiza yokusika ingabekwa ngokuhambisana ne-axisi engathathi hlangothi, kodwa ibekwe ngokuqondile ngobukhulu bodonga. Ngakho-ke i-I-profile isikwa ngokunqamula eceleni kwewebhu nangokunqamula eceleni kwe-flange, okuthola ukusatshalaliswa kwengcindezi okuboniswe ku-sl. 13.1. Esigabeni esiyindilinga (sl. 13) izingcindezi zokugunda zisatshalaliswa ngokulinganayo maqondana nobubanzi obumile futhi kwesokunxele nakwesokudla kulayini ongathathi hlangothi zifinyelela ubukhulu obuphezulu
τ = Q / πrt.
Uma isigaba sinqunywa endaweni ephakeme kakhulu noma ephansi kakhulu, ukusatshalaliswa kwengcindezi eshedayo akuguquki; nokho, uma sinqunywa ekugcineni kwesokudla kobubanzi obuvundlile (sl. 14), ingcindezi eshedayo kuleyo ndawo ilingana noziro, kuyilapho inani layo liphindeka kabili ekugcineni kwesobunxele kwalowo bubanzi ofanayo.
Umf. 14
Izigaba eziqinile
Ezingxenyeni eziqinile zesimo esingahleliwe inkinga yezingcindezi zokushefa ixhumene kakhulu nenkinga ye-torsion. Isibalo esiyisisekelo (8) kulokhu asisathembekile. Engxenyeni eyindilinga enobubanzi obungu r isibalo (8) sinikeza
τ = 4Q / 3__πr2
njengenani eliphakathi lokucindezeleka kokugunda eduze kwe-eksisi engathathi hlangothi, kanti inani langempela likhulu kuphela ngamaphesenti ambalwa.
Isikhungo sokushefa
Uma izingcindezi zokugunda zibalwa ku-U-section ngendlela echazwe ngenhla, kutholakala ukusatshalaliswa kwezingcindezi okukhonjiswe ku-sl. 15. Umphumela wamandla angaphakathi ahambisanayo amandla aphesheya Q. Esithombeni kungabonakala indawo yawo maqondana nesiphambano, okusho ukuthi awudluli phakathi nendawo yokukhanga kwesiphambano, futhi awuhlali endizeni yombambo. Uma amandla aphesheya abalwe ngokusekelwe emandleni angaphandle engenayo indawo eboniswe ku-sl. 15, umthwali awulayishwa kuphela ekugobeni, kodwa nasekujikeni (torsion).
Uma kunqunywa i-resultanti efanayo kuleyo ngxenye yesiphambano, ehambisana nezingcindezi zokugunda zomthwalo othile ovundlile, kutholakala umugqa wokusebenza wamandla e-transversal avundlile. Ekuphambaneni kwale migqa emibili yokusebenza kutholakala iphuzu eliyisici lale ngxenye yesiphambano, elibizwa ngokuthi isikhungo sokugunda M. Ku-beam akukho zingcindezi ezivela ekusonteni lapho izikhungo zokugunda zazo zonke izingxenye zesiphambano zilele emgqeni owodwa, futhi yonke imithwalo eqondile ku-axis yenduku idlula kulowo mugqa. Ngaphandle kwalokho, i-moment yomthwalo ngamunye maqondana nomugqa ohlanganisa izikhungo zokugunda imele ukugunda kokusonta.
Umdwebo 15
Umthelela wamandla e-transversal ekugobeni
Ithiyori yobunjiniyela yokugoba isekelwe ekunganakeni ukukhubazeka okubangelwa izingcindezi zokushefa. Ngakho-ke ingasetshenziswa ngempela ezindukwini ezincane nezinde, lapho lokhu kunganakwa kufanelekile futhi lapho amandla e-transversal engenawo umthelela obonakalayo ekugobeni.
Nokho, ulwazi selukhombisile ukuthi umbono wobuchwepheshe wokugoba ungase, ngezinga elithile lempumelelo, usetshenziswe nakubathwali abafushane, abade, okungesiwo umgomo wawo empeleni. Lapho-ke kuvela isidingo sokuthi umthelela wokuguquka ngenxa yezingcindezi zokugunda, ongashiwongo kulombono, uthathwe, okungenani ngokusondela, kucatshangwe kamuva.
Njengoba kunjalo nangengcindezi zokugunda τ ngenxa yamandla e-transverse kanye nokushelela okuhambisanayo γ_’ =_ τ_/G_ kusatshalaliswa ngokungalingani kusigaba. Ngakho-ke kufakwa inani labo elimaphakathi γ, elinqunywa ngendlela yokuthi amandla e-transverse kulesi silinganiso esimaphakathi sokuguquka enze emcimbini webhimu dx umsebenzi wokuguquka olingana nalowo obungatholakala ngokuhlanganisa imisebenzi yezingcindezi zokugunda ezingxenyeni ezithile zevolumu ezakha ingxenye ebonwayo yebhimu:
lapho kuvela khona
I-integral ingabalwa lapho sekwaziwa ukusatshalaliswa kwezingcindezi zokugunda esigabeni. Njengoba zonke izingcindezi zokugunda zilinganiselwe no-Q/F, inani layo lilinganisela no-Q2/F2 * F, ngakho uma kubekwa ukuthi lingu-κ__Q2/F, kutholakala
γ = κ__Q / GF.
Ukonstanta κ lubizwa nge-coeff. yokusabalala kwezingcindezi zokugunda. Kumaqhawe angunxande κ=1,2.
Fig. 16
Uma i-coeff. κ, futhi ngalokho nokuslayida okuphakathi γ, sekwaziwa, kungabalwa ukugoba okwengeziwe wQ, okubangelwe amandla e-transverse, okufanele kwengezwe ekugobeni w: ngoba ngokwesith. 16 kuyi
ngakho-ke ngenxa ye-Q = dM/dx:
lapho khona i-constant yokuhlanganisa itholakala esimweni esisodwa somkhawulo.