Matla a fracture ke thepa ea bohlokoa e bapalang karolo ea bohlokoa ho saense ea lintho tse bonahalang le boenjiniere, ho thusa ho tseba hore na thepa e tla sebetsa joang tlas'a khatello ea kelello, haholo-holo ha e hlōleha. E fana ka temohisiso mabapi le khatello e phahameng eo thepa e ka e mamellang pele e robeha, e fa baenjiniere le bo-ramahlale ba lintho tse bonahalang data e hlokahalang ho khetha lisebelisoa tse nepahetseng bakeng sa lits'ebetso tse fapaneng. Sehloohong sena se akaretsang, re tla hlahloba hore na matla a fracture ke eng, bohlokoa ba eona, mekhoa e fapaneng ea ho robeha, le hore na e ka lekoa joang sebakeng sa tlhahiso. Ho feta moo, re tla ikakhela ka setotsoana mathateng a amanang le tlhahlobo ea matla a fracture le bohlokoa ba ho utloisisa lekhalo la khatello ea maikutlo.
Fracture Strength ke eng?
Matla a ho robeha a bolela boholo ba khatello ea maikutlo kapa matla ao thepa e ka a mamellang pele e hlaheloa ke koluoa e kholo, e khetholloang ke ho robeha. Ho hloleha hona ho etsahala ha sebopeho sa ka hare sa thepa se se se sa khone ho sebetsana le mojaro o sebelisitsoeng, e leng se bakang ho ata ha crack hoo qetellong ho lebisang ho robeheng ho felletseng. Ka tloaelo e hlahisoa ka likarolo tsa khatello, joalo kapascals (Pa) or liponto ka inch square (psi), matla a ho robeha ke thepa ea bohlokoa e thusang baenjiniere ho bolela esale pele hore na lisebelisoa li tla sebetsa joang tlas'a maemo a sebele a lefats'e, haholo-holo lits'ebetsong tsa meralo moo ho hlōleha ho ka bang kotsi.
Matla a ho robeha ha thepa a itšetlehile ka lintlha tse 'maloa, ho akarelletsa le eonasebopeho sa kristale lattice, motsoako kapa sebopeho sa motsoako, le homekhoa ea tlhahisoamehang. Lisebelisoa li bonts'a maemo a fapaneng a matla a ho robeha, haholo ka lebaka la tlhophiso ea tsona ea athomo le mofuta oa maqhama lipakeng tsa liathomo.
Mefuta ea Lisebelisoa tse Thehiloeng ho Matla a Ho robeha:
- Lisebelisoa tsa Brittle: Concrete, ceramics, le grey cast iron hangata li matla ha li hatelloa empa li bontša matla a fokolang a ho robeha. Lisebelisoa tsena li khona ho sebetsana le matla a khatello hantle empa li hloleha habonolo tlas'a khatello ea maikutlo kapa ea ho kobeha.
- Lisebelisoa tsa Ductile: Tšepe e bonolo, aluminium, le li-polymer tse ngata ka kakaretso li na le matla a tlase a khatello empa matla a ho robeha a phahameng. Lisebelisoa tsena li ka holofala ka polasetiki pele li hloleha, tsa li lumella ho monya matla le ho mamella likhatello tse kholo ntle le ho phatloha.
Matla a fracture a ka fetoloa haholo kamabaka a ka ntlejoalo ka mocheso, lebelo leo ho jaroang ho etsahalang ka lona, boteng ba mefokolo kapa mefokolo ea thepa, le mofuta oa khatello ea maikutlo e sebelisitsoeng (ebang ke ho tsitsipana, ho hatella, ho kuta, joalo-joalo).
Mekhoa ea ho robeha ha thepa
Ho utloisisa mekhoa e fapaneng ea fracture ho thusa ho tseba hore na boitsebiso bo tla arabela joang tlas'a maemo a fapaneng a khatello ea kelello. Mefuta e atileng haholo ea ho robeha e kenyelletsa ho teneha, ho hatella le ho kobeha fractures. Mokhoa o mong le o mong o kenyelletsa likhakanyo tse fapaneng tsa khatello ea maikutlo le mekhoa ea ho hloleha.
1. Ho robeha ha Tensile:
Ho robeha ha sekhahla ho etsahala ha ntho e kengoa ke matla a kantle a e hulang ho latela axis e le 'ngoe. Mofuta ona oa fracture o atisa ho etsahala ka thepa tlas'a tsitsipano e hloekileng, 'me e khetholloa ka ho arohana kapa ho phatloha ha thepa e tsamaeang le sefofane se pota-potileng mojaro o sebelisoang.
- Phetoho ea Pele: Boitsebiso bo qalaelastic deformation, moo lintho tse bonahalang li lelefatsa ka lehlakoreng la mojaro o kentsoeng. Deformation e ka khutlisoa, ho bolelang hore thepa e khutlela sebopehong sa eona sa pele hang ha matla a tlosoa.
- Necking: Ha mojaro o ntse o eketseha, sebaka sa libaka se qala ho holofala haholo. Mokhahlelo ona, o tsejoang e lemolaleng, e baka ho fokotseha ha sebaka sa sefapano sebakeng sa khatello ea maikutlo e kholo. Thepa ea atoloha, 'me meeli ea eona ea kristale ea thella.
- Ultimate Tensile Strength (UTS): Matla a ho qetela a matla a bolela boholo ba khatello ea kelello eo thepa e ka e mamellang pele sebaka sa molala se e-ba sa bohlokoa, se etsang hore ho robeha ho ata ka potlako ho pholletsa le karolo eohle ea sefapano.
2. Compressive Fracture:
Ho robeha ha khatello ho etsahala ha thepa e tlas'a matla a e sutumelletsang hammoho ho latela axis ea mojaro. Mofuta ona oa ho robeha o fella kabulging, ho thuba, lekarohanotsa thepa. Ho robeha ha khatello hangata ho fella ka ho robeha hangata ha thepa e ntse e sokola ho hanela khatello ea khatello e sebelisoang.
- Elastic Deformation: Karolong ea pele, boitsebiso bo ntse bo tsoela peleelastic deformation, e ka hlaphoheloa hang ha mojaro o tlosoa. Leha ho le joalo, ha mojaro o ntse o eketseha, thepa e kena karolong ea deformation ea polasetiki.
- Plastiki Deformation le Bulging: Ka thepa ea ductile, meroalo e hatellang e baka deformation ea polasetiki, e bonahalang e le bulging perpendicular ho mojaro o sebelisitsoeng. Lisebelisuoa tse brittle, ka lehlakoreng le leng, hangata lia robeha hang ha moeli oa elastic o fetisitsoe, kaha ha li na bokhoni ba ho etsa deformation ea bohlokoa ea polasetiki.
- Matla a ho qetela: Ha boitsebiso bo fihla ho eonamatla a ho qetela, mapheo a mangata a ka ba teng, a lebisang ho arohana kapa ho oa ha thepa tlas'a mojaro o sebelisitsoeng.
3. Ho Kobeha Fracture:
Ho robeha ho kobeha ho etsahala ha thepa e le tlas'a khatello e matla le e hatellang, ka lebaka la matla a kobehang a kantle. Ho robeha ho tloaelehileng ho kobeha ho hlaha ka lehlakoreng le thata, moo thepa e utloang bolelele, 'me e ata ka botenya ba thepa.
- Mathata le Mathata a Khatello: Likhoele tse ka ntle tsa thepa (ka lehlakoreng le jereng) li na le khatello ea maikutlo, ha likhoele tse ka hare (tse khahlanong le mojaro o sebelisitsoeng) li ba le khatello ea maikutlo. Likhatello tsena li baka ho hloleha ho lehlakoreng la tsitsipano, moo ho ka bang teng ho phatloha kapa ho senyeha.
- Phatlalatso ea Crack: Ha matla a kobehang a sebelisoang a ntse a eketseha, mapetsong a qala ka lehlakoreng le tsitsitseng 'me a ka' na a ata ka ho feletseng ka botenya ba thepa, e leng se lebisang ho hlōleha.
Liteko tsa ho Fumana Matla a Fracture
Ho na le liteko tse 'maloa tse tloaelehileng tse sebelisetsoang ho fumana matla a ho robeha ha thepa. Liteko tsena li bohlokoa ho utloisisa hore na thepa e tla sebetsa joang tlas'a maemo a fapaneng a ho laela. Liteko tse tloaelehileng tsa matla a robehileng li kenyelletsa liteko tsa khatello, khatello ea maikutlo, le liteko tsa phello.
1. Teko ea Teko:
Tekong ea tensile, sampole e emeng e nang le amolala (ntja bone)sebopeho se behiloe ho axial loading ka tsitsipano e hloekileng. Teko ena e thusa ho lekola hore na thepa e arabela joang ho tsitsipano, ho fana ka lintlha ho eonamekhahlelo ea elastic le polasetiki, matla a ho qetela (UTS), leho lelefatsa nakong ya kgefutso.
- Sephetho: Boleng ba UTS bo emela khatello ea maikutlo eo thepa e tla robeha ho eona. Teko ea tensile e boetse e fana ka tlhahisoleseling mabapi le ductility le monyetla oa deformation ea polasetiki.
2. Teko ea Compression:
Teko ea khatello e kenyelletsa ho kenya block block e emeng ea liteko ka axially ka matla a hloekileng a khatello. Teko ena e lekola bokhoni ba thepa ea ho hanela khatello mme e fana ka data ho eonamatla a hatellanglecompression module.
- Sephetho: Teko e thusa ho tseba ntlha eo thepa e ke keng ea hlola e mamella matla a khatello mme e qala ho holofala ka polasetiki kapa ho hloleha.
3. Teko ea Tšusumetso:
Teko ea phello e etsoa ho lekola bokhoni ba thepa ea ho mamella meroalo ea tšohanyetso, e matla. Mohlala, hangatanotchedho ntšetsa pele ho qalisoa ha crack, e angoa ke sehlahisoa sa lebelo le holimo. Matla a monyetsoeng nakong ea tšusumetso kapa boholo ba ho robeha hoa lekanngoa.
- Sephetho: Teko ena e thusa ho tseba thepa e kangmatla a tshusumetsoleboimana, tse bohlokoa bakeng sa lisebelisoa tse pepesehetseng maemo a matla kapa a ts'oenyehileng.
Melemo ea ho Lekola Matla a Fracture ho Tlhahiso
Ho lekola matla a ho robeha ho fana ka lintlha tsa bohlokoa tse tataisang khetho ea lisebelisoa bakeng sa lits'ebetso tse ikhethileng. Melemo e meng ea bohlokoa e kenyelletsa:
- Ho Khetholla Mefokolo: Teko e lumella bahlahisi ho bona mefokolo kapa bofokoli ba thepa e ka lebisang ho hloleheng pele ho nako tlasa maemo a itseng.
- Khetho ea Lintho: Lisebelisoa tse fapaneng li bonts'a matla a fapaneng a ho robeha, 'me ho utloisisa boitšoaro bona ho thusa baenjiniere ho khetha lisebelisoa tse ka mamellang likhatello tse lebelletsoeng lits'ebetsong tse ikhethileng.
- Ntlafatso ea Moqapi: Teko ea matla a ho robeha e thusa ho tseba likhatello tsa khatello ea maikutlo kapa lintlha tse fokolang moralong, e lumellang baenjiniere ho ntlafatsa khetho ea thepa le moralo oa geometry bakeng sa ts'ebetso e ntle.
- Polokeho: Ho etsa liteko tsa matla a ho robeha ho thusa ho tseba lisebelisoa tse ka hlolehang tlas'a maemo a khethehileng a ho roala, ho fokotsa likotsi lits'ebetsong tsa bohlokoa tse kang sefofane, likoloi le lisebelisoa tsa bongaka.
Mathata a ho Leka Matla a Fracture ho Tlhahiso
Leha e le bohlokoa, ho leka matla a ho robeha ha ho etsoa ho hlahisa mathata a 'maloa:
- Phapang ea Lintho: Esita le ka har'a beche e tšoanang ea tlhahiso, thepa ea thepa e ka fapana, e lebisang ho se lumellane ho liphetho tsa tlhahlobo ea matla a fracture. Joalo ka sekala sa tlhahiso, thekiso ea thepa e ka hlahisa phapang e patehileng.
- Boholo ba Mohlala le Geometry: Boholo le sebōpeho sa sampole ea teko li ama haholo liphetho tsa matla a ho robeha. Mehlala e nyane ea liteko e kanna ea se emele ka nepo boitšoaro ba likarolo tse kholo, haholo ha ho ameha lijeometri tse rarahaneng.
- Loading Conditions: Matla a ho robeha a ka fapana ho itšetlehile ka boemo ba ho laela, ho etsa hore ho be thata ho etsisa maemo a sebele a khatello ea kelello litekong tsa laboratori.
- Lintlha tsa Tikoloho: Lintho tse kang mocheso, mongobo le ho pepesehela lik'hemik'hale li ka ama matla a ho robeha ha thepa. Ho etsa liteko tlas'a maemo a laoloang a tikoloho ho hloka lisebelisoa tse khethehileng.
- Strain Rate Sensitivity: Lisebelisoa tse ling li bonts'a thepa ea ho robeha e itšetlehileng ka sekhahla, ho bolelang hore matla a ho robeha a ka fapana ho latela hore na mojaro o sebelisoa ka potlako hakae, ho thatafatsa liphetho tsa liteko.
The Stress-Strain Curve le Matla a Ho robeha
Thekhatello ea maikutlo-mokokotloka litšoantšo e emela kamano lipakeng tsa khatello ea maikutlo le khatello e hlahisoang ke ntho e itseng. E fana ka leseli la bohlokoa mabapi le hore na thepa e holofala joang ha e le tlas'a mojaro, 'me e thusa baenjiniere ho utloisisa boits'oaro ba mochini oa thepa, haholoholo ho latela matla a eona a ho robeha.
- Elastic Deformation: Karolong ea pele ea ho jara, thepa e ba le deformation elastic, moo khatello ea maikutlo le khatello e lekanang. Ha o tlosa moroalo, thepa e khutlela sebopeho sa eona sa pele.
- Phetoho ea polasetiki: Ha khatello ea kelello e ntse e eketseha, thepa e kena sebakeng sa deformation ea polasetiki, moo boitsebiso bo nang le liphetoho tse sa feleng tsa sebopeho.
- Matla a ho qetela le Ntlha ea ho robeha: Ntlha eo thepa e ke keng ea hlola e mamella mojaro o sebelisitsoeng e tsejoa e le ntlha ea ho robeha, hangata e hlalosoang ka mokokotlo oa khatello ea kelello e lematla a ho qetela (UTS).
Litšobotsi le Mefuta ea Ho robeha
Litšobotsi tsa ho robeha li ka fana ka temohisiso ea bohlokoa mabapi le boitšoaro ba thepa tlas'a khatello. Lintlha tsa bohlokoa li kenyelletsa:
- Lifofane tsa Cleavage: Lifofane tse boreleli, tse bataletseng tseo thepa e senyehang ka tsona, hangata ho ea ka meeli ea kristale.
- Dimples: Ho sithabela ho pota-pota holim'a bokaholimo ba ho robeha, ho bonts'a ho robeha ha ductile le ho monya matla.
- Beola Melomo: Bokaholimo bo robehileng bo bonts'ang masela a fibrous kapa a phofshoana, sebopeho sa micro-void coalescence.
- Hackles: Lipaterone tsa Chevron sebakeng se robehileng se bontšang tsela ea ho ata ha crack.
Matla a Fracture ea Ceramics le Glass
Lisebelisoa tse kangli-ceramicslekhalase ea inorganicbonts'a mekhoa e fapaneng ea ho robeha ka lebaka la sebopeho sa bona sa athomo.
- Li-ceramics: Li tsejoa ka matla a tsona a phahameng le ho satalla, li-ceramics le tsona li brittle haholo. Li na le litlamo tse matla tsa athomo empa li na le matla a fokolang a ho holofala ka polasetiki, e leng se etsang hore li sekamele ho robeha ha tšohanyetso ha li le maemong a mahlonoko a khatello ea maikutlo.
- Khalase ea Inorganic: Ho fapana le li-ceramics, khalase ea inorganic (mohlala, khalase ea silica) e na le sebopeho sa amorphous, se lebisang ho ajoa ka mokhoa o ts'oanang oa khatello ea maikutlo. Le hoja e na le matla a phahameng a ho robeha ho feta li-ceramics, e boetse e na le maikutlo a matla haholo ho bokooa bo ka holimo bo ka fokotsang matla a eona haholo.
Qetello
Matla a ho robeha ke thepa ea bohlokoa eo baenjiniere le bo-ramahlale ba lintho tse bonahalang ba lokelang ho e ela hloko ha ba rala likarolo kapa meaho e tla ba le khatello ea maikutlo e kholo. Ho utloisisa matla a ho robeha ha thepa le mabaka a e susumetsang ho ka thusa ho ntlafatsa khetho ea thepa, ho ntlafatsa polokeho ea sehlahisoa, le ho ntlafatsa katleho ea moralo. Ebang ke ka liteko tse thata, tse hatellang, kapa tsa tšusumetso, tlhahlobo e nepahetseng ea matla a ho robeha e bohlokoa bakeng sa ho netefatsa ho ts'epahala le ho tšoarella ha lihlahisoa liindastering ho tloha sebakeng sa sefofane ho isa lisebelisoa tsa bongaka.
Nako ea poso: Jan-25-2025
