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Ama-Actuator asetshenziswa yonke indawo futhi adale ukunyakaza okulawulwayo ngokusebenzisa amandla okuvuselela noma i-torque efanele ukwenza imisebenzi ehlukahlukene ekukhiqizeni nasekuzenzekeleni kwezimboni. Isidingo sama-drive asheshayo, amancane futhi asebenza kahle kakhulu siqhuba ukusungula izinto ezintsha ekwakhiweni kwama-drive. Ama-drive e-Shape Memory Alloy (SMA) anikeza izinzuzo eziningi ngaphezu kwama-drive avamile, kufaka phakathi isilinganiso esiphezulu samandla-kuya-esisindoni. Kulesi sifundo, i-actuator esekwe ku-SMA enezimpaphe ezimbili yathuthukiswa ehlanganisa izinzuzo zemisipha enama-feather yezinhlelo zezinto eziphilayo kanye nezakhiwo ezihlukile zama-SMA. Lolu cwaningo luhlola futhi lwandise ama-actuator e-SMA angaphambilini ngokuthuthukisa imodeli yezibalo ye-actuator entsha ngokusekelwe kulungiselelo lwentambo ye-SMA ye-bimodal futhi luyihlole ngokuhlola. Uma kuqhathaniswa nama-drive aziwayo asekelwe ku-SMA, amandla okusebenza e-drive entsha okungenani aphezulu ngokuphindwe kahlanu (kufika ku-150 N). Ukulahlekelwa kwesisindo okuhambisanayo cishe kungama-67%. Imiphumela yokuhlaziywa kokuzwela kwamamodeli ezibalo iwusizo ekulungiseni amapharamitha okuklama nokuqonda amapharamitha ayisihluthulelo. Lolu cwaningo luqhubeka nokuveza idrayivu yesigaba se-Nth enamazinga amaningi engasetshenziswa ukuthuthukisa amandla okuguquguquka. Ama-actuator emisipha e-dipvalerate asekelwe ku-SMA anezinhlelo zokusebenza eziningi ezahlukene, kusukela ekwakheni okuzenzakalelayo kuya ezinhlelweni zokulethwa kwemithi ngokunemba.
Izinhlelo zebhayoloji, njengezakhiwo zemisipha yezilwane ezincelisayo, zingasebenzisa ama-actuator amaningi angabonakali1. Izilwane ezincelisayo zinezakhiwo zemisipha ezahlukene, ngasinye sisebenzela injongo ethile. Kodwa-ke, ingxenye enkulu yesakhiwo sezicubu zemisipha yezilwane ezincelisayo ingahlukaniswa ngezigaba ezimbili ezibanzi. Okufanayo nokupena. Ema-hamstrings nakwamanye ama-flexor, njengoba igama lisho, imisipha ehambisanayo inezintambo zemisipha ezihambisana ne-tendon ephakathi. Uchungechunge lwezintambo zemisipha lubekwe eceleni futhi luxhunywe ngokusebenzayo yizicubu ezixhumene ezizungezile. Nakuba le misipha kuthiwa inohambo olukhulu (ukunciphisa iphesenti), amandla ayo emisipha iyonke alinganiselwe kakhulu. Ngokuphambene nalokho, emisipha ye-triceps calf2 (lateral gastrocnemius (GL)3, medial gastrocnemius (GM)4 kanye ne-soleus (SOL)) kanye ne-extensor femoris (quadriceps)5,6 izicubu zemisipha epena zitholakala emisipheni ngayinye7. Esakhiweni esipena, izintambo zemisipha emisipheni epena zitholakala kuzo zombili izinhlangothi ze-tendon ephakathi ngama-angles a-oblique (ama-angles apenati). I-Pennate ivela egameni lesiLatini elithi “penna”, elisho “ipeni”, futhi, njengoba kuboniswe ku-Fig. 1 inokubukeka okufana nokwezimpaphe. Imicu yemisipha ye-pennate imfushane futhi igobile ku-axis ende yemisipha. Ngenxa yesakhiwo se-pinnate, ukuhamba okuphelele kwale misipha kuyancipha, okuholela ezingxenyeni eziphambene nezinde zenqubo yokufinyeza. Ngakolunye uhlangothi, ukusebenza kwale misipha kuholela emandleni aphezulu emisipha ngenxa yendlela indawo ye-cross-sectional elinganiswa ngayo ngokomzimba. Ngakho-ke, endaweni ethile ye-cross-sectional, imisipha ye-pennate izoba namandla futhi izokhiqiza amandla aphezulu kunemisipha enemicu efanayo. Amandla akhiqizwa imicu ngayinye akhiqiza amandla emisipha ezingeni le-macroscopic kuleyo zicubu zemisipha. Ngaphezu kwalokho, inezakhiwo ezihlukile njengokuncipha okusheshayo, ukuvikelwa ekulimaleni kokudonsa, ukuncishiswa. Iguqula ubudlelwano phakathi kokufakwa kwe-fiber kanye nokukhishwa kwamandla emisipha ngokusebenzisa izici ezihlukile kanye nobunzima bejometri bokuhlelwa kwe-fiber okuhambisana nemigqa yesenzo semisipha.
Kuboniswe imidwebo yeskimu yemiklamo ye-actuator esekwe ku-SMA ekhona maqondana nokwakheka kwemisipha ye-bimodal, isibonelo (a), emele ukusebenzisana kwamandla okuthinta lapho idivayisi emise okwesandla eqhutshwa izintambo ze-SMA ifakwe khona kurobhothi elihambayo elizimele elinamasondo amabili9,10. , (b) I-prosthesis ye-orbital ye-robotic ene-prosthesis ye-orbital ebekwe ngendlela ephikisanayo ye-SMA efakwe entwasahlobo. Indawo yeso lokufakelwa ilawulwa yisiginali esivela emsipheni weso11, (c) Ama-actuator e-SMA afanele ukusetshenziswa ngaphansi kwamanzi ngenxa yempendulo yawo yemvamisa ephezulu kanye ne-bandwidth ephansi. Kulokhu kulungiselelwa, ama-actuator e-SMA asetshenziselwa ukudala ukunyakaza kwamagagasi ngokulingisa ukunyakaza kwezinhlanzi, (d) Ama-actuator e-SMA asetshenziselwa ukudala irobhothi yokuhlola ipayipi elincane elingasebenzisa isimiso sokunyakaza kwe-inch worm, esilawulwa ukunyakaza kwezintambo ze-SMA ngaphakathi kwesiteshi 10, (e) sibonisa isiqondiso sezintambo zemisipha yokufinyela futhi sikhiqize amandla okufinyela ezicutshini ze-gastrocnemius, (f) sibonisa izintambo ze-SMA ezihlelwe ngesimo sezintambo zemisipha esakhiweni semisipha e-pennate.
Ama-actuator aseyingxenye ebalulekile yezinhlelo zemishini ngenxa yezinhlelo zawo eziningi. Ngakho-ke, isidingo sama-drive amancane, asheshayo futhi asebenza kahle siba yinto ebalulekile. Naphezu kwezinzuzo zawo, ama-drive endabuko abonakalisile ukuthi ayabiza futhi adla isikhathi ukuwagcina. Ama-actuator e-hydraulic kanye ne-pneumatic ayinkimbinkimbi futhi ayabiza futhi angakwazi ukuguguleka, izinkinga zokugcoba kanye nokwehluleka kwezingxenye. Ukuphendula isidingo, kugxilwe ekuthuthukiseni ama-actuator angabizi kakhulu, alungiselelwe kahle ubukhulu futhi athuthukile asekelwe ezintweni ezihlakaniphile. Ucwaningo oluqhubekayo lubheka ama-actuator anezingqimba ze-shape memory alloy (SMA) ukuze kuhlangatshezwane nalesi sidingo. Ama-actuator e-hierarchical ahlukile ngoba ahlanganisa ama-actuator amaningi ahlukene abe yizinhlelo ezincane ze-macro scale eziyinkimbinkimbi ukuze anikeze ukusebenza okwandisiwe nokwandisiwe. Kulokhu, izicubu zemisipha yomuntu ezichazwe ngenhla zinikeza isibonelo esihle kakhulu esinezingqimba eziningi salolu hlobo lwe-actuation olunezingqimba eziningi. Ucwaningo lwamanje luchaza i-drive ye-SMA enamazinga amaningi enezinto eziningana zokushayela ngazinye (izintambo ze-SMA) ezihambisana nokuqondiswa kwefayibha okukhona emisipheni ye-bimodal, okuthuthukisa ukusebenza kwe-drive iyonke.
Inhloso eyinhloko ye-actuator ukukhiqiza amandla omshini njengomfutho kanye nokususwa ngokuguqula amandla kagesi. Ama-alloy enkumbulo yokwakheka ayiklasi lezinto "ezihlakaniphile" ezingabuyisela isimo sazo emazingeni okushisa aphezulu. Ngaphansi kwemithwalo ephezulu, ukwanda kwezinga lokushisa kwentambo ye-SMA kuholela ekubuyiselweni kwesimo, okuholela ekumisweni kwamandla okusebenza okuphezulu uma kuqhathaniswa nezinto ezahlukahlukene ezihlakaniphile eziboshwe ngqo. Ngesikhathi esifanayo, ngaphansi kwemithwalo yomshini, ama-SMA aba brittle. Ngaphansi kwezimo ezithile, umthwalo ojikelezayo ungamunca futhi ukhulule amandla omshini, ubonise izinguquko zesimo esiguquguqukayo. Lezi zakhiwo eziyingqayizivele zenza i-SMA ifaneleke kakhulu kuma-sensor, ukudambisa ukudlidliza kanye ikakhulukazi ama-actuator12. Ngalokhu engqondweni, kube nocwaningo oluningi kuma-drive asekelwe ku-SMA. Kufanele kuqashelwe ukuthi ama-actuator asekelwe ku-SMA aklanyelwe ukunikeza ukunyakaza kokuhumusha kanye nokujikeleza kwezinhlelo zokusebenza ezahlukahlukene13,14,15. Nakuba amanye ama-actuator ajikelezayo ethuthukisiwe, abacwaningi banesithakazelo esikhulu kuma-actuator aqondile. Lawa ma-actuator aqondile angahlukaniswa abe izinhlobo ezintathu zama-actuator: ama-actuator anobukhulu obubodwa, ama-displacement kanye nama-differential 16. Ekuqaleni, ama-hybrid drive adalwa ngokuhlanganiswa ne-SMA kanye namanye ama-drive avamile. Esinye isibonelo esinjalo se-actuator eqondile ye-hybrid esekelwe ku-SMA ukusetshenziswa kwentambo ye-SMA enenjini ye-DC ukuhlinzeka ngamandla okukhipha angaba ngu-100 N kanye nokufuduka okuphawulekayo17.
Enye yentuthuko yokuqala kuma-drive asekelwe ngokuphelele ku-SMA kwakuyi-SMA parallel drive. Kusetshenziswa izintambo eziningi ze-SMA, i-SMA-based parallel drive yenzelwe ukwandisa amandla kagesi e-drive ngokubeka zonke izintambo ze-SMA18 ngendlela efanayo. Ukuxhumeka kwe-parallel kwama-actuator akudingi nje amandla engeziwe, kodwa futhi kukhawulela amandla okukhipha ucingo olulodwa. Okunye okubi kwama-actuator asekelwe ku-SMA ukuhamba okulinganiselwe abangakufeza. Ukuxazulula le nkinga, kwadalwa i-SMA cable beam equkethe i-flexible beam ephambukile ukuze kwandiswe ukuhamba nokufeza ukunyakaza okuqondile, kodwa ayizange ikhiqize amandla aphezulu19. Izakhiwo ezithambile nezindwangu eziguquguqukayo zamarobhothi asekelwe kuma-alloy ememori yesimo zakhiwe ngokuyinhloko ukuze kukhuliswe umthelela20,21,22. Ezinhlelweni zokusebenza lapho kudingeka khona isivinini esikhulu, amaphampu aqhutshwa yi-compact abikwe kusetshenziswa ama-SMA efilimu encane yezinhlelo zokusebenza eziqhutshwa yi-micropump23. Imvamisa yokushayela ye-thin film SMA membrane iyisici esibalulekile ekulawuleni isivinini somshayeli. Ngakho-ke, ama-SMA linear motors anempendulo engcono kakhulu kune-SMA spring noma rod motors. Amarobhothi athambile kanye nobuchwepheshe bokubamba ezinye izinhlelo zokusebenza ezimbili ezisebenzisa ama-actuator asekelwe ku-SMA. Isibonelo, ukuze kuthathelwe indawo i-actuator ejwayelekile esetshenziswa ku-25 N space clamp, kwasungulwa i-shape memory alloy parallel actuator 24. Kwesinye isimo, i-actuator ethambile ye-SMA yakhiwa ngokusekelwe ocingweni olune-matrix ehlanganisiwe ekwazi ukukhiqiza amandla aphezulu okudonsa angu-30 N. Ngenxa yezakhiwo zawo zemishini, ama-SMA asetshenziswa futhi ukukhiqiza ama-actuator alingisa izenzakalo zebhayoloji. Enye intuthuko enjalo ifaka irobhothi elinamaseli ayi-12 eliyi-biomimetic yento efana ne-earthworm ene-SMA ukukhiqiza ukunyakaza kwe-sinusoidal ukuya ekushayweni26,27.
Njengoba kushiwo ngaphambili, kunomkhawulo wamandla aphezulu angatholakala kuma-actuator asekelwe ku-SMA akhona. Ukuze kuxazululwe le nkinga, lolu cwaningo luveza isakhiwo semisipha ye-bimodal ye-biomimetic. Iqhutshwa ucingo lwe-alloy yememori yesimo. Luhlinzeka ngesistimu yokuhlukanisa ehlanganisa izintambo eziningana ze-alloy yememori yesimo. Kuze kube manje, azikho i-actuator ezisekelwe ku-SMA ezinokwakheka okufanayo ezibikiwe ezincwadini. Lolu hlelo oluyingqayizivele nolusha olusekelwe ku-SMA lwathuthukiswa ukuze lufunde ukuziphatha kwe-SMA ngesikhathi sokulungiswa kwemisipha ye-bimodal. Uma kuqhathaniswa nama-actuator asekelwe ku-SMA akhona, umgomo walolu cwaningo kwakuwukudala i-actuator ye-dipvalerate ye-biomimetic ukuze ikhiqize amandla aphezulu kakhulu ngevolumu encane. Uma kuqhathaniswa nama-drive aqhutshwa yi-stepper motor avamile asetshenziswa ku-automation yokwakha ye-HVAC kanye nezinhlelo zokulawula, umklamo we-bimodal drive ohlongozwayo we-SMA unciphisa isisindo sendlela yokushayela ngo-67%. Okulandelayo, amagama athi “muscle” kanye “drive” asetshenziswa ngokushintshana. Lolu cwaningo luhlola ukulingiswa kwe-multiphysics kwe-drive enjalo. Ukuziphatha kwemishini kwezinhlelo ezinjalo kuye kwafundwa ngezindlela zokuhlola nezokuhlaziya. Ukusatshalaliswa kwamandla kanye nokushisa kwahlolwa kabanzi nge-voltage yokufaka engu-7 V. Ngemva kwalokho, kwenziwa ukuhlaziywa kwe-parametric ukuze kuqondwe kangcono ubudlelwano phakathi kwamapharamitha ayisihluthulelo kanye namandla okukhipha. Okokugcina, ama-actuator asezingeni eliphezulu aye acatshangelwa futhi imiphumela yezinga eliphezulu iphakanyisiwe njengendawo yesikhathi esizayo engaba khona yama-actuator angewona ama-magnetic ezinhlelo zokusebenza zokufakelwa. Ngokusho kwemiphumela yezifundo ezishiwo ngenhla, ukusetshenziswa kokwakheka kwesigaba esisodwa kukhiqiza amandla okungenani aphindwe kane kuya kahlanu kunama-actuator asekelwe ku-SMA abikiwe. Ngaphezu kwalokho, amandla okushayela afanayo akhiqizwa yi-drive yamazinga amaningi amaningi aboniswe ukuthi angaphezu kwezikhathi eziyishumi kunama-drive asekelwe ku-SMA avamile. Ucwaningo lube selubika amapharamitha ayisihluthulelo kusetshenziswa ukuhlaziywa kokuzwela phakathi kwemiklamo ehlukene kanye neziguquguquko zokufaka. Ubude bokuqala bentambo ye-SMA (\(l_0\)), i-angle ye-pinnate (\(\alpha\)) kanye nenani lezintambo ezilodwa (n) ku-strand ngayinye ngayinye kunomthelela omubi kakhulu ngobukhulu bamandla okushayela, kuyilapho i-voltage yokufaka (amandla) ivele ihlobene kahle.
Intambo ye-SMA ikhombisa umphumela wememori yesimo (i-SME) obonakala emndenini wama-alloy e-nickel-titanium (i-Ni-Ti). Ngokuvamile, ama-SMA abonisa izigaba ezimbili ezincike ekushiseni: isigaba sokushisa esiphansi kanye nesigaba sokushisa okuphezulu. Zombili izigaba zinezakhiwo ezihlukile ngenxa yokuba khona kwezakhiwo ezahlukene zekristalu. Esigabeni se-austenite (isigaba sokushisa okuphezulu) esikhona ngaphezu kokushisa kokuguqulwa, izinto ezibonakalayo zibonisa amandla aphezulu futhi azikhuli kahle ngaphansi komthwalo. Ingxube iziphatha njengensimbi engagqwali, ngakho iyakwazi ukumelana nezingcindezi eziphezulu zokucindezela. Isebenzisa lesi sici sama-alloy e-Ni-Ti, izintambo ze-SMA zigobile ukuze zakhe i-actuator. Amamodeli afanele okuhlaziya athuthukiswa ukuze aqonde indlela eyisisekelo yokuziphatha kokushisa kwe-SMA ngaphansi kwethonya lamapharamitha ahlukahlukene kanye namajiyometri ahlukahlukene. Kutholakale ukuvumelana okuhle phakathi kwemiphumela yokuhlola kanye nokuhlaziya.
Kwenziwe ucwaningo lokuhlola ku-prototype eboniswe ku-Fig. 9a ukuhlola ukusebenza kwe-bimodal drive esekelwe ku-SMA. Ezimbili zalezi zakhiwo, amandla akhiqizwa yi-drive (amandla emisipha) kanye nokushisa kwentambo ye-SMA (ukushisa kwe-SMA), kwalinganiswa ngokuhlola. Njengoba umehluko we-voltage ukhuphuka kulo lonke ubude bentambo ku-drive, izinga lokushisa lentambo liyakhuphuka ngenxa yomphumela wokushisa we-Joule. I-voltage yokufaka yasetshenziswa emijikelezweni emibili yamasekhondi ayi-10 (eboniswe njengamachashazi abomvu ku-Fig. 2a, b) enesikhathi sokupholisa samasekhondi ayi-15 phakathi komjikelezo ngamunye. Amandla okuvimba alinganiswa kusetshenziswa i-piezoelectric strain gauge, kanti ukusatshalaliswa kwezinga lokushisa kwentambo ye-SMA kwaqashwa ngesikhathi sangempela kusetshenziswa ikhamera ye-LWIR yezinga eliphezulu lesayensi (bheka izici zemishini esetshenziswe kuThebula 2). kukhombisa ukuthi ngesikhathi sesigaba se-voltage ephezulu, izinga lokushisa lentambo liyakhuphuka ngokuzumayo, kodwa lapho kungekho mandla agelezayo, izinga lokushisa lentambo liyaqhubeka nokwehla. Ekusethweni kwamanje kokuhlola, izinga lokushisa lentambo ye-SMA lehle ngesikhathi sesigaba sokupholisa, kodwa lalisengaphezu kwezinga lokushisa elizungezile. Kumfanekiso 2e kukhombisa isithombe sezinga lokushisa kuntambo ye-SMA ethathwe kukhamera ye-LWIR. Ngakolunye uhlangothi, kumfanekiso 2a kukhombisa amandla okuvimba akhiqizwa uhlelo lokushayela. Lapho amandla emisipha edlula amandla okubuyisela entwasahlobo, ingalo eshukumayo, njengoba kuboniswe kuMfanekiso 9a, iqala ukuhamba. Lapho nje ukusebenza kuqala, ingalo eshukumayo ixhumana nenzwa, idale amandla omzimba, njengoba kuboniswe kumfanekiso 2c, d. Lapho izinga lokushisa eliphezulu liseduze ne-\(84\,^{\circ}\hbox {C}\), amandla aphezulu abonwayo angama-105 N.
Igrafu ikhombisa imiphumela yokuhlola yezinga lokushisa lentambo ye-SMA kanye namandla akhiqizwa yi-actuator ye-bimodal esekelwe ku-SMA phakathi kwemijikelezo emibili. I-voltage yokufaka isetshenziswa emijikelezweni emibili yemizuzwana eyi-10 (eboniswe njengamachashazi abomvu) kanye nesikhathi sokupholisa semizuzwana eyi-15 phakathi komjikelezo ngamunye. Intambo ye-SMA esetshenziswe kulezi zivivinyo kwakuyintambo ye-Flexinol engu-0.51 mm ububanzi evela ku-Dynalloy, Inc. (a) Igrafu ikhombisa amandla okuhlola atholwe ngemijikelezo emibili, (c, d) ikhombisa izibonelo ezimbili ezizimele zesenzo se-actuator yengalo ehambayo ku-transducer ye-PACEline CFT/5kN piezoelectric force ye-transducer, (b) igrafu ikhombisa izinga lokushisa eliphezulu lentambo ye-SMA yonke ngesikhathi semijikelezo emibili, (e) ikhombisa isithombe sokushisa esithathwe kuntambo ye-SMA kusetshenziswa ikhamera yesofthiwe ye-FLIR ResearchIR LWIR. Amapharamitha ejometri acatshangelwayo kuzivivinyo anikezwe kuThebula. lokuqala.
Imiphumela yokulingisa yemodeli yezibalo kanye nemiphumela yokuhlola iqhathaniswa ngaphansi kwesimo se-voltage yokufaka engu-7V, njengoba kuboniswe ku-Fig.5. Ngokwemiphumela yokuhlaziywa kwe-parametric kanye nokugwema amathuba okushisa ngokweqile kwentambo ye-SMA, amandla angu-11.2 W anikezwa i-actuator. Ukunikezwa kwamandla kagesi e-DC okuhleliwe kwasetshenziswa ukuhlinzeka nge-7V njenge-voltage yokufaka, kanti ugesi ongu-1.6A walinganiswa kuyo yonke intambo. Amandla akhiqizwa yi-drive kanye nokushisa kwe-SDR kuyanda lapho ugesi usetshenziswa. Nge-voltage yokufaka engu-7V, amandla aphezulu okukhipha atholakala emiphumeleni yokulingisa kanye nemiphumela yokuhlola yomjikelezo wokuqala ngu-78 N no-96 N, ngokulandelana. Emjikelezweni wesibili, amandla aphezulu okukhipha okulingisa kanye nemiphumela yokuhlola yayingu-150 N no-105 N, ngokulandelana. Umehluko phakathi kokulinganiswa kwamandla okuvala kanye nedatha yokuhlola kungenzeka ngenxa yendlela esetshenziswa ukukala amandla okuvala. Imiphumela yokuhlola eboniswe ku-fig. I-5a ihambisana nokulinganiswa kwamandla okukhiya, okwalinganiswa lapho i-drive shaft ixhumana ne-PACEline CFT/5kN piezoelectric force transducer, njengoba kuboniswe ku-Fig. 2s. Ngakho-ke, lapho i-drive shaft ingaxhumani ne-force sensor ekuqaleni kwendawo yokupholisa, amandla aba yi-zero ngokushesha, njengoba kuboniswe ku-Fig. 2d. Ngaphezu kwalokho, amanye amapharamitha athinta ukwakheka kwamandla emijikelezweni elandelayo amanani esikhathi sokupholisa kanye ne-coefficient yokudluliselwa kokushisa okuguquguqukayo emjikelezweni odlule. Kusukela ku-Fig. 2b, kungabonakala ukuthi ngemva kwesikhathi sokupholisa semizuzwana eyi-15, intambo ye-SMA ayizange ifinyelele izinga lokushisa legumbi ngakho-ke yayinezinga lokushisa eliphakeme lokuqala (\(40\,^{\circ }\hbox {C}\)) emjikelezweni wesibili wokushayela uma kuqhathaniswa nomjikelezo wokuqala (\(25\, ^{\circ}\hbox {C}\)). Ngakho-ke, uma kuqhathaniswa nomjikelezo wokuqala, izinga lokushisa lentambo ye-SMA ngesikhathi somjikelezo wesibili wokushisa lifinyelela izinga lokushisa lokuqala le-austenite (\(A_s\)) ngaphambili futhi lihlala esikhathini sokuguquka isikhathi eside, okuholela ekucindezelekeni nasekuqineni. Ngakolunye uhlangothi, ukusatshalaliswa kwezinga lokushisa ngesikhathi somjikelezo wokushisa nokupholisa okutholwe ekuhlolweni nasekulingiseni kunokufana okuphezulu kwekhwalithi nezibonelo ezivela ekuhlaziyweni kwe-thermographic. Ukuhlaziywa kokuqhathanisa kwedatha yokushisa yentambo ye-SMA kusukela ekuhlolweni nasekulingiseni kubonise ukuvumelana ngesikhathi somjikelezo wokushisa nokupholisa futhi ngaphakathi kokubekezelelana okwamukelekayo kwedatha yokuhlola. Izinga lokushisa eliphezulu lentambo ye-SMA, elitholwe emiphumeleni yokulingisa nokuhlola komjikelezo wokuqala, lingu-\(89\,^{\circ }\hbox {C}\) kanye no-\(75\,^{\circ }\hbox {C }\, ngokulandelana ), kanti emjikelezweni wesibili izinga lokushisa eliphezulu lentambo ye-SMA lingu-\(94\,^{\circ }\hbox {C}\) kanye no-\(83\,^{\circ }\ hbox {C}\). Imodeli ethuthukiswe ngokuyisisekelo iqinisekisa umphumela womphumela wememori yesimo. Indima yokukhathala nokushisa ngokweqile ayizange icatshangelwe kulokhu kubuyekezwa. Esikhathini esizayo, imodeli izothuthukiswa ukuze ifake umlando wokucindezeleka wentambo ye-SMA, okwenza ifaneleke kakhulu kuzinhlelo zokusebenza zobunjiniyela. Amandla okukhipha idrayivu kanye nezindawo zokushisa ze-SMA ezitholwe kubhulokhi ye-Simulink zingaphakathi kokubekezelelana okuvumelekile kwedatha yokuhlola ngaphansi kwesimo se-voltage yokufaka engu-7 V. Lokhu kuqinisekisa ukunemba nokuthembeka kwemodeli yezibalo ethuthukisiwe.
Imodeli yezibalo yathuthukiswa endaweni yeMathWorks Simulink R2020b kusetshenziswa izibalo eziyisisekelo ezichazwe esigabeni sezindlela. Ku-fig. 3b kukhombisa umdwebo webhlokhi wemodeli yezibalo yeSimulink. Imodeli yalingiswa nge-7V input voltage pulse njengoba kuboniswe ku-Fig. 2a, b. Amanani amapharamitha asetshenziswe ekulingiseni abhalwe kuThebula 1. Imiphumela yokulingisa izinqubo zesikhashana ivezwe ku-Fig. 1 no-1. Izibalo 3a no-4. Ku-fig. 4a, b kukhombisa i-voltage ebangelwayo ku-SMA wire kanye namandla akhiqizwa yi-actuator njengomsebenzi wesikhathi. Ngesikhathi sokuguqulwa okuphambene (ukushisa), lapho izinga lokushisa lentambo ye-SMA, \(T < A_s^{\prime}\) (izinga lokushisa lokuqala kwesigaba se-austenite elishintshiwe ngokucindezeleka), izinga lokushintsha kwengxenye yevolumu ye-martensite (\(\dot{\xi }\)) lizoba yi-zero. Ngesikhathi sokuguqulwa okuphambene (ukushisa), lapho izinga lokushisa lentambo ye-SMA, \(T < A_s^{\prime}\) (izinga lokushisa lokuqala kwesigaba se-austenite elishintshiwe ngokucindezeleka), izinga lokushintsha kwengxenye yevolumu ye-martensite (\(\dot{\ xi }\)) lizoba yi-zero. Во время обратного превращения (нагрева), когда температура проволоки SMA, \(T < A_s^{\prime}\) (температура начала аустенитной модинция, напряжением), скорость изменения объемной доли мартенсита (\(\dot{\ xi }\)) будет равно нулю. Ngesikhathi sokuguqulwa okuphambene (ukushisa), lapho izinga lokushisa lentambo ye-SMA, \(T < A_s^{\prime}\) (izinga lokushisa lokuqala le-austenite elishintshiwe ngokucindezeleka), izinga lokushintsha kwengxenye yevolumu ye-martensite (\(\dot{\ xi }\ )) lizoba yi-zero.在反向转变（加热）过程中，当SMA 线温度\(T < A_s^{\prime}\)（应力修正奥氏体相起始温度）时，马氏体体积分数的变化率（\(\xi}\)為在 反向 转变 (加热) 中 , 当 当 当 线 温度 \ (t При обратном превращении (нагреве) при температуре проволоки СПФ \(T < A_s^{\prime}\) изменения объемной доли мартенсита (\( \dot{\ xi }\)) будет равно нулю. Ngesikhathi sokuguqulwa okuphambene (ukushisa) ekushiseni kwentambo ye-SMA \(T < A_s^{\prime}\) (izinga lokushisa le-nucleation yesigaba se-austenite, elilungisiwe ngenxa yokucindezeleka), izinga lokushintsha engxenyeni yevolumu ye-martensite (\( \dot{\ xi }\)) lizoba ngu-zero.Ngakho-ke, izinga lokushintsha kokucindezeleka (\(\dot{\sigma}\)) lizoncika esilinganisweni sokucindezeleka (\(\dot{\epsilon}\)) kanye ne-gradient yokushisa (\(\dot{T} \) ) kuphela ngokusebenzisa i-equation (1). Kodwa-ke, njengoba intambo ye-SMA ikhula ekushiseni futhi iwela (\(A_s^{\prime}\)), isigaba se-austenite siqala ukwakheka, futhi (\(\dot{\xi}\)) sithathwa njengenani elinikeziwe le-equation (3). Ngakho-ke, izinga lokushintsha kwe-voltage (\(\dot{\sigma}\)) lilawulwa ngokubambisana yi-\(\dot{\epsilon}, \dot{T}\) kanye ne-\(\dot{\xi}\) elilingana nelinikezwe kufomula (1). Lokhu kuchaza izinguquko ze-gradient ezibonwe kumamephu okucindezeleka ashintshashintshayo ngesikhathi kanye namandla ngesikhathi somjikelezo wokushisa, njengoba kuboniswe ku-Fig. 4a, b.
(a) Umphumela wokulingisa obonisa ukusatshalaliswa kwezinga lokushisa kanye nokushisa kwe-junction okubangelwa ukucindezeleka ku-actuator ye-divalerate esekelwe ku-SMA. Lapho izinga lokushisa lentambo lidlula izinga lokushisa lokuguquka kwe-austenite esigabeni sokushisa, izinga lokushisa lokuguquka kwe-austenite eliguquliwe liqala ukwanda, futhi ngokufanayo, lapho izinga lokushisa lenduku yentambo lidlula izinga lokushisa lokuguquka kwe-martensitic esigabeni sokupholisa, izinga lokushisa lokuguquka kwe-martensitic liyancipha. I-SMA yokulinganisa okuhlaziya inqubo yokusebenza. (Ukuze uthole umbono oningiliziwe wesistimu ngayinye engaphansi yemodeli ye-Simulink, bheka isigaba sesithasiselo sefayela elingeziwe.)
Imiphumela yokuhlaziywa kokusatshalaliswa kwamapharamitha ahlukene iboniswa emijikelezweni emibili ye-voltage yokufaka engu-7V (imijikelezo yokufudumeza yemizuzwana eyi-10 kanye nemijikelezo yokuphola yemizuzwana eyi-15). Ngenkathi u-(ac) no-(e) bebonisa ukusatshalaliswa ngokuhamba kwesikhathi, ngakolunye uhlangothi, u-(d) no-(f) bebonisa ukusatshalaliswa ngokushisa. Ezimweni zokufaka ezifanele, ukucindezeleka okuphezulu okubonwe yi-106 MPa (ngaphansi kuka-345 MPa, amandla okukhiqiza intambo), amandla angama-150 N, ukufuduka okuphezulu kungu-270 µm, kanti ingxenye encane yevolumu ye-martensitic ingu-0.91. Ngakolunye uhlangothi, ushintsho ekucindezelekeni kanye noshintsho engxenyeni yevolumu ye-martensite ngokushisa kufana nezici ze-hysteresis.
Incazelo efanayo isebenza ekuguqulweni okuqondile (ukupholisa) kusuka esigabeni se-austenite kuya esigabeni se-martensite, lapho izinga lokushisa lentambo ye-SMA (T) kanye nezinga lokushisa lokugcina lesigaba se-martensite esishintshiwe ngokucindezeleka (\(M_f^{\prime}\ )) lihle kakhulu. Ku-fig. 4d,f ukhombisa ushintsho ekucindezelekeni okubangelwayo (\(\sigma\)) kanye nengxenye yevolumu ye-martensite (\(\xi\)) kuntambo ye-SMA njengomsebenzi woshintsho ekushiseni kwentambo ye-SMA (T), kuzo zombili imijikelezo yokushayela. Ku-fig. Fig. 3a ukhombisa ushintsho ekushiseni kwentambo ye-SMA ngokuhamba kwesikhathi kuye ngokuthi i-voltage yokufaka ishaya kanjani. Njengoba kungabonakala esithombeni, izinga lokushisa lentambo liyaqhubeka nokukhula ngokuhlinzeka ngomthombo wokushisa ku-zero voltage kanye nokupholisa okulandelayo kwe-convective. Ngesikhathi sokushisa, ukuguqulwa kabusha kwe-martensite ibe yisigaba se-austenite kuqala lapho izinga lokushisa le-SMA wire (T) liwela izinga lokushisa le-nucleation le-austenite elilungisiwe ngokucindezeleka (\(A_s^{\prime}\)). Phakathi nalesi sigaba, intambo ye-SMA iyacindezelwa futhi i-actuator ikhiqiza amandla. Futhi ngesikhathi sokupholisa, lapho izinga lokushisa lentambo ye-SMA (T) liwela izinga lokushisa le-nucleation lesigaba se-martensite esishintshiwe ngokucindezeleka (\(M_s^{\prime}\)) kuba noshintsho oluhle kusuka esigabeni se-austenite kuya esigabeni se-martensite. Amandla okushayela ayancipha.
Izici eziyinhloko zekhwalithi yedrayivu ye-bimodal esekelwe ku-SMA zingatholakala emiphumeleni yokulingisa. Uma kwenzeka ukufakwa kwe-voltage pulse, izinga lokushisa lentambo ye-SMA liyakhuphuka ngenxa yomphumela wokushisa we-Joule. Inani lokuqala lengxenye yevolumu ye-martensite (\(\xi\)) lisethwe ku-1, njengoba izinto ziqala esigabeni se-martensitic ngokugcwele. Njengoba intambo iqhubeka nokushisa, izinga lokushisa lentambo ye-SMA lidlula izinga lokushisa le-austenite nucleation elilungisiwe ngokucindezeleka \(A_s^{\prime}\), okuholela ekunciphiseni kwengxenye yevolumu ye-martensite, njengoba kuboniswe kuMfanekiso 4c. Ngaphezu kwalokho, kuMfanekiso 4e kukhombisa ukusatshalaliswa kwemivimbo ye-actuator ngesikhathi, nakuMfanekiso 5 - amandla okushayela njengomsebenzi wesikhathi. Uhlelo oluhlobene lwezibalo luhlanganisa izinga lokushisa, ingxenye yevolumu ye-martensite, kanye nokucindezeleka okuthuthuka kuntambo, okuholela ekuncipheni kwentambo ye-SMA kanye namandla akhiqizwa yi-actuator. Njengoba kuboniswe kuMfanekiso. Ukwehluka kwe-voltage okungu-4d, f, okunezinga lokushisa kanye nokwehluka kwengxenye yevolumu ye-martensite okunezinga lokushisa kufana nezici ze-hysteresis ze-SMA esimweni esilingisiwe ku-7 V.
Ukuqhathaniswa kwamapharamitha okushayela kutholakale ngokuhlola kanye nokubala kokuhlaziya. Izintambo zifakwe ku-voltage yokufaka evunguziwe engu-7 V imizuzwana eyi-10, bese zipholiswa imizuzwana eyi-15 (isigaba sokupholisa) ngemijikelezo emibili. I-angle ye-pinnate isethwe ku-\(40^{\circ}\) kanti ubude bokuqala bentambo ye-SMA emlenzeni ngamunye wephini busethwe ku-83mm. (a) Ukulinganisa amandla okushayela ngeseli yomthwalo (b) Ukuqapha izinga lokushisa lentambo ngekhamera ye-infrared yokushisa.
Ukuze kuqondwe ithonya lamapharamitha angokomzimba emandleni akhiqizwa yidrayivu, kwenziwa ukuhlaziywa kokuzwela kwemodeli yezibalo kumapharamitha akhethiwe angokomzimba, futhi amapharamitha ahlelwa ngokwethonya lawo. Okokuqala, ukusampula kwamapharamitha emodeli kwenziwa kusetshenziswa izimiso zokuklama zokuhlola ezilandela ukusatshalaliswa okufanayo (bheka Isigaba Esingeziwe Sokuhlaziywa Kokuzwela). Kulesi simo, amapharamitha emodeli afaka i-voltage yokufaka (\(V_{in}\)), ubude bentambo ye-SMA yokuqala (\(l_0\)), i-angle kanxantathu (\(\alpha\)), i-bias spring constant (\( K_x\ )), i-convective heat transfer coefficient (\(h_T\)) kanye nenani lamagatsha e-unimodal (n). Esinyathelweni esilandelayo, amandla emisipha aphezulu akhethwa njengemfuneko yokuklama isifundo futhi imiphumela ye-parametric yesethi ngayinye yeziguquguquko emandleni yatholakala. Imidwebo yesiphepho sokuhlaziywa kokuzwela yatholakala kuma-coefficients okuhlobana kwepharamitha ngayinye, njengoba kuboniswe ku-Fig. 6a.
(a) Amanani e-coefficient yokuhambisana kwamapharamitha emodeli kanye nomthelela wawo emandleni aphezulu okukhipha amaqembu ahlukile angu-2500 wamapharamitha emodeli angenhla aboniswe ku-plot yesiphepho. Igrafu ikhombisa ukuhambisana kwezinga lezinkomba eziningana. Kusobala ukuthi i-\(V_{in}\) iyona kuphela ipharamitha enokuxhumana okuhle, kanti i-\(l_0\) iyipharamitha enokuxhumana okubi okuphezulu. Umphumela wamapharamitha ahlukahlukene ezinhlanganisweni ezahlukene emandleni emisipha ephezulu uboniswa ku-(b, c). I-\(K_x\) isukela ku-400 kuya ku-800 N/m kanti i-n isukela ku-4 kuya ku-24. I-Voltage (\(V_{in}\)) ishintshe kusuka ku-4V kuya ku-10V, ubude bentambo (\(l_{0} \)) ishintshe kusuka ku-40 kuya ku-100 mm, kanye ne-engeli yomsila (\ (\alpha \)) ishintshe kusuka ku-\ (20 - 60 \, ^ {\circ }\).
Ku-fig. 6a kukhombisa i-tornado plot yama-coefficient ahlukahlukene okuhlobana kwepharamitha ngayinye enezidingo zomklamo wamandla okushayela aphezulu. Kusukela ku-fig. 6a kungabonakala ukuthi ipharamitha ye-voltage (\(V_{in}\)) ihlobene ngqo namandla okukhipha aphezulu, kanye ne-coefficient yokudlulisa ukushisa okuguquguqukayo (\(h_T\)), i-flame angle (\( \alpha\)), i-displacement spring constant ( \(K_x\)) ihlobene kabi namandla okukhipha kanye nobude bokuqala (\(l_0\)) bentambo ye-SMA, kanye nenani lamagatsha e-unimodal (n) libonisa ukuxhumana okunamandla okuphambene Endabeni yokuxhumana okuqondile Endabeni yenani eliphakeme le-coefficient yokuhlobana kwe-voltage (\(V_ {in}\)) libonisa ukuthi le pharamitha inomphumela omkhulu kakhulu ekuphumeni kwamandla. Okunye ukuhlaziywa okufanayo kulinganisa amandla aphezulu ngokuhlola umphumela wamapharamitha ahlukene ekuhlanganisweni okuhlukene kwezikhala ezimbili zokubala, njengoba kuboniswe ku-Fig. 6b, c. \(V_{in}\) kanye \(l_0\), \(\alpha\) kanye \(l_0\) zinamaphethini afanayo, futhi igrafu ikhombisa ukuthi \(V_{in}\) kanye \(\alpha\) kanye \(\alpha\) zinamaphethini afanayo. Amanani amancane ka-\(l_0\) aholela emandleni aphezulu aphezulu. Ezinye izigcawu ezimbili zihambisana noMfanekiso 6a, lapho u-n kanye no-\(K_x\) behlobene kabi kanye no-\(V_{in}\) behlobene kahle. Lokhu kuhlaziya kusiza ukuchaza nokulungisa amapharamitha anethonya lapho amandla okukhipha, ukushaya kanye nokusebenza kahle kwesistimu yokushayela kungashintshwa khona ukuze kuhambisane nezidingo kanye nokusetshenziswa.
Umsebenzi wocwaningo wamanje wethula futhi uphenya amadrayivu asezingeni eliphezulu anamazinga e-N. Kuhlelo lwezinga ezimbili, njengoba kuboniswe ku-Fig. 7a, lapho esikhundleni sentambo ngayinye ye-SMA ye-actuator yezinga lokuqala, kufezwa ukuhlelwa kwe-bimodal, njengoba kuboniswe ku-Fig. 9e. Ku-Fig. 7c kukhombisa ukuthi intambo ye-SMA izungezwe kanjani ingalo enyakazayo (ingalo eyisizayo) ehamba kuphela ohlangothini olude. Kodwa-ke, ingalo enyakazayo eyinhloko iyaqhubeka nokuhamba ngendlela efanayo nengalo enyakazayo ye-actuator yesigaba sokuqala esinezigaba eziningi. Ngokuvamile, idrayivu yesigaba se-N idalwa ngokufaka esikhundleni sentambo yesigaba se-\(N-1\) ye-SMA ngedrayivu yesigaba sokuqala. Ngenxa yalokho, igatsha ngalinye lilingisa idrayivu yesigaba sokuqala, ngaphandle kwegatsha elibamba intambo uqobo. Ngale ndlela, izakhiwo ezifakwe izidleke zingakhiwa ezidala amandla amakhulu kaningana kunamandla amadrayivu ayinhloko. Kulolu cwaningo, ezingeni ngalinye, ubude bentambo ye-SMA esebenza kahle obuyi-1 m bucatshangelwe, njengoba kuboniswe kufomethi yethebula ku-Fig. 7d. Ugesi odlula ku-wire ngayinye kumklamo ngamunye we-unimodal kanye ne-prestress kanye ne-voltage ephumayo ku-wire ngayinye ye-SMA kuyafana ku-level ngayinye. Ngokusho kwemodeli yethu yokuhlaziya, amandla okukhipha ahlobene kahle ne-level, kuyilapho ukufuduka kuhlobene kabi. Ngesikhathi esifanayo, kwaba nokuhwebelana phakathi kokufuduka namandla emisipha. Njengoba kubonwe ku-Fig. 7b, ngenkathi amandla aphezulu etholakala enanini elikhulu lezendlalelo, ukufuduka okukhulu kuyabonakala ku-layer ephansi kakhulu. Lapho izinga lokuqondisa lisethelwe ku-\(N=5\), amandla emisipha aphezulu angu-2.58 kN atholakala ngemivimbo emibili ebonwe \(\upmu\)m. Ngakolunye uhlangothi, idrayivu yesigaba sokuqala ikhiqiza amandla angu-150 N ku-stroke engu-277 \(\upmu\)m. Ama-actuator asezingeni eliningi ayakwazi ukulingisa imisipha yangempela yezinto eziphilayo, lapho imisipha yokwenziwa esekelwe kuma-alloys enkumbulo yesimo ikwazi ukukhiqiza amandla aphezulu kakhulu ngokunyakaza okuqondile nokucophelelayo. Imikhawulo yalo mklamo omncane ukuthi njengoba uhla lwezinhlelo lukhula, ukunyakaza kunciphisa kakhulu futhi ubunzima benqubo yokukhiqiza idrayivu buyanda.
(a) Uhlelo lwe-actuator olunezigaba ezimbili (\(N=2\)) olunezingqimba zememori ye-alloy linear actuator luboniswa ekucushweni kwe-bimodal. Imodeli ehlongozwayo ifinyelelwa ngokufaka esikhundleni sentambo ye-SMA ku-actuator enezingqimba zesigaba sokuqala ngesinye i-actuator enezingqimba zesigaba esisodwa. (c) Ukucushwa okushintshiwe kwe-actuator yesigaba sesibili enezingqimba eziningi. (b) Ukusatshalaliswa kwamandla kanye nokushintshana kuye ngenani lamazinga kuchaziwe. Kutholakale ukuthi amandla aphezulu e-actuator ahlobene kahle nezinga lesikali kugrafu, kuyilapho ukushaywa kuhlobene kabi nezinga lesikali. I-current kanye ne-pre-voltage kuntambo ngayinye zihlala zingaguquki kuzo zonke amazinga. (d) Ithebula libonisa inani lama-taps kanye nobude bentambo ye-SMA (i-fiber) ezingeni ngalinye. Izici zezintambo zikhonjiswa yi-index 1, kanti inani lamagatsha esibili (elixhunywe kumlenze oyinhloko) likhonjiswa ngenombolo enkulu kunazo zonke ku-subscript. Isibonelo, ezingeni lesi-5, i-\(n_1\) ibhekisela enanini lezintambo ze-SMA ezikhona esakhiweni ngasinye se-bimodal, kanti i-\(n_5\) ibhekisela enanini lemilenze esekelayo (eyodwa exhunywe emlenzeni oyinhloko).
Izindlela ezahlukahlukene ziye zaphakanyiswa abacwaningi abaningi ukuze babonise ukuziphatha kwama-SMA ngenkumbulo yesimo, okuncike ezimpawini ze-thermomechanical ezihambisana nezinguquko ezinkulu esakhiweni sekristalu ezihambisana noshintsho lwesigaba. Ukwakhiwa kwezindlela zokwakha kuyinkimbinkimbi ngokwemvelo. Imodeli ye-phenomenological esetshenziswa kakhulu iphakanyiswa yiTanaka28 futhi isetshenziswa kabanzi ezinhlelweni zobunjiniyela. Imodeli ye-phenomenological ephakanyisiwe yiTanaka [28] icabanga ukuthi ingxenye yevolumu ye-martensite iwumsebenzi wokubonisa izinga lokushisa nokucindezeleka. Kamuva, uLiang noRogers29 noBrinson30 baphakamise imodeli lapho i-phase transition dynamics yayithathwa njengomsebenzi we-cosine we-voltage nokushisa, ngokuguqulwa okuncane kumodeli. UBecker noBrinson baphakamise imodeli ye-kinetic esekelwe ku-phase diagram ukuze babonise ukuziphatha kwezinto ze-SMA ngaphansi kwezimo zokulayisha ezingahleliwe kanye noshintsho oluyingxenye. UBanerjee32 usebenzisa indlela ye-Bekker ne-Brinson31 phase diagram dynamics ukuze alingise i-manipulator eyodwa yenkululeko eyathuthukiswa ngu-Elahinia no-Ahmadian33. Izindlela ze-Kinetic ezisekelwe kuma-phase diagram, ezicabangela ushintsho lwe-voltage olungeyona i-monotonic oluhambisana nokushisa, kunzima ukuzisebenzisa ezinhlelweni zobunjiniyela. I-Elakhinia ne-Ahmadian zidonsela ukunaka kulezi ziphutha zamamodeli e-phenomenological akhona futhi ziphakamisa imodeli ye-phenomenological ende ukuhlaziya nokuchaza ukuziphatha kwememori yesimo ngaphansi kwanoma yiziphi izimo zokulayisha eziyinkimbinkimbi.
Imodeli yesakhiwo sentambo ye-SMA inikeza ukucindezeleka (\(\sigma\)), uhlobo (\(\epsilon\)), izinga lokushisa (T), kanye nengxenye yevolumu ye-martensite (\(\xi\)) yentambo ye-SMA. Imodeli yesakhiwo se-phenomenological yahlongozwa okokuqala yi-Tanaka28 futhi kamuva yamukelwa yi-Liang29 kanye ne-Brinson30. I-derivative ye-equation inesimo:
lapho u-E kuyi-modulus ye-SMA Young encike esigabeni etholakale kusetshenziswa i-\(\displaystyle E=\xi E_M + (1-\xi )E_A\) kanye ne-\(E_A\) kanye ne-\(E_M\) emele i-modulus ka-Young iyi-austenitic kanye ne-martensitic phases, ngokulandelana, kanti i-coefficient of thermal expansion imelelwa yi-\(\theta _T\). Isici somnikelo wokuguquka kwesigaba yi-\(\Omega = -E \epsilon _L\) kanye ne-\(\epsilon _L\) iwuhlobo lokucindezeleka okukhulu okutholakalayo ku-SMA wire.
I-phase dynamics equation ihambisana nomsebenzi we-cosine owathuthukiswa nguLiang29 futhi kamuva wamukelwa nguBrinson30 esikhundleni somsebenzi we-exponential ophakanyiswe nguTanaka28. Imodeli yokuguqulwa kwesigaba iyisandiso semodeli ephakanyiswe ngu-Elakhinia no-Ahmadian34 futhi yaguqulwa ngokusekelwe ezimweni zokuguqulwa kwesigaba ezinikezwe nguLiang29 noBrinson30. Izimo ezisetshenziswe kule modeli yokuguqulwa kwesigaba zisebenza ngaphansi kwemithwalo eyinkimbinkimbi ye-thermomechanical. Ngesikhathi ngasinye, inani lengxenye yevolumu ye-martensite libalwa lapho kwenziwa imodeli ye-constitutive equation.
I-equation yokuguqulwa kabusha ebusayo, evezwa ukuguqulwa kwe-martensite ibe yi-austenite ngaphansi kwezimo zokushisa, ilandelayo:
lapho \(\xi\) kuyingxenyana yevolumu ye-martensite, \(\xi _M\) iyingxenyana yevolumu ye-martensite etholwe ngaphambi kokushisa, \(\displaystyle a_A = \pi /(A_f – A_s)\), \ ( \displaystyle b_A = -a_A/C_A\) kanye \(C_A\) – amapharamitha okulinganisa ijika, izinga lokushisa lentambo ye-T – SMA, \(A_s\) kanye \(A_f\) – ukuqala nokuphela kwesigaba se-austenite, ngokulandelana, izinga lokushisa.
I-equation yokulawula ukuguqulwa okuqondile, emelelwa ukuguqulwa kwesigaba se-austenite ibe yi-martensite ngaphansi kwezimo zokupholisa, yile:
lapho \(\xi _A\) kuyingxenyana yevolumu ye-martensite etholwe ngaphambi kokupholisa, \(\displaystyle a_M = \pi /(M_s – M_f)\), \(\displaystyle b_M = -a_M/C_M\) kanye \ (C_M \) – amapharamitha okufaka ijika, izinga lokushisa lentambo ye-T – SMA, \(M_s\) kanye \(M_f\) – izinga lokushisa lokuqala nelokugcina le-martensite, ngokulandelana.
Ngemva kokwehlukaniswa kwezibalo (3) kanye (4), izibalo zokuguqulwa okuphambene nokuqondile zenziwa zibe lula ngendlela elandelayo:
Ngesikhathi sokuguqulwa phambili nangemuva \(\eta _{\sigma}\) kanye \(\eta _{T}\) kuthatha amanani ahlukene. Izibalo eziyisisekelo ezihlobene ne-\(\eta _{\sigma}\) kanye ne-\(\eta _{T}\) zithathwe futhi zaxoxwa ngokuningiliziwe esigabeni esengeziwe.
Amandla okushisa adingekayo ukuphakamisa izinga lokushisa lentambo ye-SMA avela kumphumela wokushisa we-Joule. Amandla okushisa amuncwa noma akhishwa yintambo ye-SMA amelelwa ukushisa okucashile kokuguqulwa. Ukulahleka kokushisa entanjeni ye-SMA kungenxa yokuguqulwa okuphoqelelwe, futhi uma kubhekwa umphumela omncane wokukhanya, i-equation yebhalansi yamandla okushisa ilandelayo:
Lapho i-\(m_{wire}\) iyisisindo esiphelele sentambo ye-SMA, \(c_{p}\) ingumthamo wokushisa othize we-SMA, \(V_{in}\) ingumthamo osetshenziswa kuntambo, \(R_{ohm} \ ) – ukumelana okuncike esigabeni i-SMA, okuchazwa ngokuthi; \(R_{ohm} = (l/A_{cross})[\xi r_M + (1-\xi )r_A]\ ) lapho i-\(r_M\ ) kanye ne-\(r_A\) kungukumelana kwesigaba se-SMA ku-martensite kanye ne-austenite, ngokulandelana, \(A_{c}\) yindawo engaphezulu yentambo ye-SMA, \(\Delta H \) iyi-alloy yememori yesimo. Ukushisa okucashile kokuguquka kwentambo, i-T kanye ne-\(T_{\infty}\) amazinga okushisa entambo ye-SMA kanye nendawo ezungezile, ngokulandelana.
Uma ucingo lwe-alloy yememori yesimo luqhutshwa, ucingo luyacindezelwa, ludale amandla egatsheni ngalinye lomklamo we-bimodal obizwa ngokuthi i-fiber force. Amandla emicu entanjeni ngayinye yocingo lwe-SMA ndawonye adala amandla emisipha ukuze asebenze, njengoba kuboniswe ku-Fig. 9e. Ngenxa yokuba khona kwentwasahlobo ehlukanisayo, amandla emisipha ephelele ye-Nth multilayer actuator yile:
Ukufaka i-\(N = 1\) ku-equation (7), amandla emisipha yesigaba sokuqala se-bimodal drive prototype angatholakala kanje:
lapho u-n kuyinombolo yemilenze eyodwa, \(F_m\) amandla emisipha akhiqizwa yi-drive, \​(F_f\) amandla e-fiber ku-SMA wire, \(K_x\) ukuqina kwe-bias. intwasahlobo, \(\alpha\) yi-engeli kanxantathu, \(x_0\) ukususwa kokuqala kwentwasahlobo ye-bias ukubamba ikhebula le-SMA endaweni ecindezelwe ngaphambili, kanye \(\Delta x\) ukuhamba kwe-actuator.
Ukufuduka okuphelele noma ukunyakaza kwedrayivu (\(\Delta x\)) kuye ngokuthi i-voltage (\(\sigma\)) kanye nobunzima (\(\epsilon\)) ku-SMA wire yesigaba se-Nth, idrayivu isethwe ku-(bheka Fig. ingxenye eyengeziwe yomphumela):
Izibalo ze-kinematic zinikeza ubudlelwano phakathi kokuguqulwa kwedrayivu (\(\epsilon\)) kanye nokususwa noma ukufuduka (\(\Delta x\)). Ukuguqulwa kwentambo ye-Arb njengomsebenzi wobude bentambo ye-Arb yokuqala (\(l_0\)) kanye nobude bentambo (l) nganoma yisiphi isikhathi i-t kwelinye igatsha le-unimodal kanje:
lapho \(l = \sqrt{l_0^2 +(\Delta x_1)^2 – 2 l_0 (\Delta x_1) \cos \alpha _1}\) itholakala ngokusebenzisa ifomula ye-cosine ku-\(\Delta\)ABB ', njengoba kuboniswe kuMfanekiso 8. Kwidrayivu yesigaba sokuqala (\(N = 1\)), \(\Delta x_1\) ingu-\(\Delta x\), kanye \(\alpha _1\) ingu-\(\alpha \) njengoba kuboniswe kuMfanekiso 8, ngokuhlukanisa isikhathi ku-Equation (11) nokufaka inani lika-l, izinga lokucindezeleka lingabhalwa kanje:
lapho i-\(l_0\) ingubude bokuqala bentambo ye-SMA, i-l ingubude bentambo nganoma yisiphi isikhathi i-t kwelinye igatsha le-unimodal, i-\(\epsilon\) ingukuguquguquka okuthuthukiswe kuntambo ye-SMA, kanye ne-\(\alpha \) ingu-engeli kanxantathu, i-\(\Delta x\) ingu-drive offset (njengoba kuboniswe kuMfanekiso 8).
Zonke izakhiwo ze-n ezine-single-peak (\(n=6\) kulesi sibalo) zixhunywe ochungechungeni nge-\(V_{in}\) njenge-voltage yokufaka. Isigaba I: Umdwebo we-schematic wentambo ye-SMA ekucushweni kwe-bimodal ngaphansi kwezimo ze-voltage zero Isigaba II: Isakhiwo esilawulwayo siboniswa lapho intambo ye-SMA icindezelwa khona ngenxa yokuguqulwa okuphambene, njengoba kuboniswe umugqa obomvu.
Njengobufakazi bomqondo, idrayivu ye-bimodal esekelwe ku-SMA yathuthukiswa ukuze kuhlolwe ukutholwa okulingisiwe kwezibalo ezingaphansi ngemiphumela yokuhlola. Imodeli ye-CAD ye-bimodal linear actuator iboniswe ku-fig. 9a. Ngakolunye uhlangothi, ku-fig. 9c ikhombisa umklamo omusha ohlongozwayo woxhumano lwe-prismatic olujikelezayo kusetshenziswa i-actuator esekelwe ku-SMA enezindilinga ezimbili enesakhiwo se-bimodal. Izingxenye zedrayivu zenziwe kusetshenziswa ukukhiqizwa okungeziwe kuphrinta ye-Ultimaker 3 Extended 3D. Izinto ezisetshenziselwa ukuphrinta kwe-3D kwezingxenye yi-polycarbonate efanelekile ezintweni ezingamelana nokushisa njengoba iqinile, ihlala isikhathi eside futhi inokushisa okuphezulu kwengilazi yokuguquka (110-113 \(^{\circ }\) C). Ngaphezu kwalokho, intambo ye-alloy yememori yesimo se-Flexinol ye-Dynalloy, Inc. yasetshenziswa ekuhlolweni, futhi izakhiwo zezinto ezihambisana nentambo ye-Flexinol zasetshenziswa ekulingiseni. Izintambo eziningi ze-SMA zihlelwe njengezintambo ezikhona ekuhlelweni kwemisipha ye-bimodal ukuze kutholakale amandla aphezulu akhiqizwa yi-actuators yezendlalelo eziningi, njengoba kuboniswe ku-Fig. 9b, d.
Njengoba kuboniswe kuMfanekiso 9a, i-acute angle eyakhiwe yintambo ye-SMA yengalo eshukumayo ibizwa ngokuthi i-angle (\(\alpha\)). Ngama-terminal clamps anamathele kuma-clamps angakwesokunxele nakwesokudla, intambo ye-SMA ibanjwa nge-engeli ye-bimodal efiselekayo. Idivayisi ye-bias spring ebanjwe esixhumini sentwasahlobo iklanyelwe ukulungisa amaqembu ahlukene e-bias spring extension ngokwenani (n) lezintambo ze-SMA. Ngaphezu kwalokho, indawo yezingxenye ezihambayo iklanyelwe ukuze intambo ye-SMA ivezwe endaweni yangaphandle ukuze kuphole ngenkani. Amapuleti aphezulu naphansi enhlangano esuswayo asiza ukugcina intambo ye-SMA ipholile ngama-cutouts akhishwe aklanyelwe ukunciphisa isisindo. Ngaphezu kwalokho, zombili iziphetho zentambo ye-CMA zinamathele kuma-terminals angakwesokunxele nakwesokudla, ngokulandelana, nge-crimp. I-plunger inamathiselwe kolunye uhlangothi lwenhlangano eshukumayo ukuze kugcinwe igebe phakathi kwamapuleti aphezulu naphansi. I-plunger isetshenziselwa futhi ukusebenzisa amandla okuvimba ku-sensor ngokuxhumana ukuze kulinganiswe amandla okuvimba lapho intambo ye-SMA iqhutshwa.
Isakhiwo semisipha ye-bimodal i-SMA sixhunywe ngogesi ngokulandelana futhi sinikwa amandla yi-input pulse voltage. Ngesikhathi somjikelezo we-voltage pulse, lapho kusetshenziswa i-voltage futhi i-SMA wire ishiswa ngaphezu kokushisa kokuqala kwe-austenite, ubude bentambo ku-strand ngayinye buyafinyezwa. Lokhu kuhoxiswa kusebenzisa i-subassembly yengalo eshukumayo. Lapho i-voltage ibekwe ku-zero kumjikelezo ofanayo, intambo ye-SMA efudumele yayipholiswa ngaphansi kokushisa kobuso be-martensite, ngaleyo ndlela ibuyela endaweni yayo yokuqala. Ngaphansi kwezimo zokucindezeleka okungu-zero, intambo ye-SMA iqale yelulwe kancane ngesiphethu se-bias ukuze ifinyelele esimweni se-martensitic esihlukanisiwe. Isikulufu, lapho intambo ye-SMA idlula khona, sihamba ngenxa yokucindezelwa okudalwe ngokusebenzisa i-voltage pulse kuntambo ye-SMA (i-SPA ifinyelela esigabeni se-austenite), okuholela ekusebenzeni kwe-movable lever. Lapho intambo ye-SMA ihoxiswa, intwasahlobo ye-bias idala amandla aphikisayo ngokunweba intwasahlobo. Uma ukucindezeleka ku-voltage ye-impulse kuba yi-zero, intambo ye-SMA iyanwebeka futhi ishintshe ukuma kwayo ngenxa yokupholisa okuphoqelelwe kwe-convection, ifinyelele esigabeni se-martensitic esiphindwe kabili.
Uhlelo lwe-actuator oluqondile olusekelwe ku-SMA lune-bimodal configuration lapho izintambo ze-SMA zibekwe khona. (a) lubonisa imodeli ye-CAD ye-prototype, ekhuluma ngezinye zezingxenye kanye nezincazelo zazo ze-prototype, (b, d) imelela i-prototype yokuhlola ethuthukisiwe35. Ngenkathi (b) ikhombisa umbono ophezulu we-prototype enokuxhumeka kukagesi kanye neziphethu ze-bias kanye nama-strain gauge asetshenzisiwe, (d) ikhombisa umbono wombono wokusetha. (e) Umdwebo wesistimu ye-actuation eqondile enezintambo ze-SMA ezibekwe nge-bimodal nganoma yisiphi isikhathi t, okubonisa isiqondiso kanye nenkambo ye-fiber kanye namandla emisipha. (c) Kuphakanyiswe uxhumano lwe-prismatic olujikelezayo lwe-2-DOF lokufaka i-actuator esekelwe ku-SMA enamapulangwe amabili. Njengoba kuboniswe, isixhumanisi sidlulisela ukunyakaza okuqondile kusuka kudrayivu engezansi kuya engalweni ephezulu, kudala uxhumano olujikelezayo. Ngakolunye uhlangothi, ukunyakaza kwama-prism amabili kufana nokunyakaza kwedrayivu yesigaba sokuqala esinezingqimba eziningi.
Kwenziwe ucwaningo lokuhlola ku-prototype eboniswe ku-Fig. 9b ukuhlola ukusebenza kwe-bimodal drive esekelwe ku-SMA. Njengoba kuboniswe ku-Fig. 10a, ukusethwa kokuhlola kwakuqukethe ukunikezwa kwamandla e-DC okuhleliwe ukuze kunikezwe i-voltage yokufaka ezintanjeni ze-SMA. Njengoba kuboniswe ku-Fig. 10b, i-piezoelectric strain gauge (PACEline CFT/5kN) yasetshenziswa ukukala amandla okuvimba kusetshenziswa i-Graphtec GL-2000 data logger. Idatha iqoshwa yi-host ukuze kuqhutshekwe nocwaningo. Ama-Strain gauges nama-charge amplifiers adinga ukunikezwa kwamandla okuqhubekayo ukuze kukhiqizwe isignali ye-voltage. Izimpawu ezihambisanayo ziguqulwa zibe yimiphumela yamandla ngokuya ngokuzwela kwe-piezoelectric force sensor kanye neminye imingcele njengoba kuchaziwe kuThebula 2. Lapho kusetshenziswa i-voltage pulse, izinga lokushisa le-SMA wire liyakhuphuka, okubangela ukuthi i-SMA wire icindezeleke, okubangela ukuthi i-actuator ikhiqize amandla. Imiphumela yokuhlola yokukhishwa kwamandla emisipha nge-input voltage pulse engu-7 V iboniswe ku-Fig. 2a.
(a) Uhlelo lwe-actuator oluqondile olusekelwe ku-SMA lwasungulwa kulolu vivinyo ukuze kulinganiswe amandla akhiqizwa yi-actuator. Iseli lomthwalo lilinganisa amandla okuvimba futhi linikwa amandla yi-24 V DC. Ukwehla kwamandla kagesi angu-7 V kwasetshenziswa kulo lonke ubude bekhebula kusetshenziswa ugesi we-GW Instek ohleliwe we-DC. Intambo ye-SMA iyancipha ngenxa yokushisa, futhi ingalo eshukumayo ixhumana neseli lomthwalo futhi inamandla okuvimba. Iseli lomthwalo lixhunywe ku-data logger ye-GL-2000 futhi idatha igcinwa ku-host ukuze icutshungulwe kabanzi. (b) Umdwebo okhombisa uchungechunge lwezingxenye zesethaphu sokuhlola sokulinganisa amandla emisipha.
Ama-alloy enkumbulo yokwakheka avuselelwa amandla okushisa, ngakho-ke izinga lokushisa liba yipharamitha ebalulekile yokufunda isenzakalo senkumbulo yokwakheka. Ngokuhlola, njengoba kuboniswe ku-Fig. 11a, ukulinganisa ukushisa kanye nokulinganisa izinga lokushisa kwenziwa ku-actuator ye-SMA-based divalerate. Umthombo we-DC ohlelekayo usebenzise i-voltage yokufaka ezintanjeni ze-SMA ekusethweni kokuhlola, njengoba kuboniswe ku-Fig. 11b. Ukushintsha kwezinga lokushisa kwentambo ye-SMA kwalinganiswa ngesikhathi sangempela kusetshenziswa ikhamera ye-LWIR enesinqumo esiphezulu (FLIR A655sc). I-host isebenzisa isofthiwe ye-ResearchIR ukurekhoda idatha ukuze icutshungulwe ngemva kokuqhubeka. Lapho kusetshenziswa i-voltage pulse, izinga lokushisa lentambo ye-SMA liyakhuphuka, okubangela ukuthi intambo ye-SMA inciphe. Ku-Fig. 2b ibonisa imiphumela yokuhlola yokushisa kwentambo ye-SMA uma kuqhathaniswa nesikhathi se-voltage yokufaka ye-7V.