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Ii-Actuators zisetyenziswa kuyo yonke indawo kwaye zenza intshukumo elawulwayo ngokusebenzisa amandla okuvuselela okanye i-torque echanekileyo ukwenza imisebenzi eyahlukeneyo kwimveliso nakwi-automation yemizi-mveliso. Imfuneko yee-drives ezikhawulezayo, ezincinci nezisebenzayo ngakumbi kukuqhuba ubuchule kuyilo lwee-drive. Ii-Shape Memory Alloy (SMA) drives zibonelela ngeenzuzo ezininzi kunee-drives eziqhelekileyo, kubandakanya umlinganiselo ophezulu wamandla ukuya kubunzima. Kule dissertation, i-actuator esekwe kwi-SMA eneentsiba ezimbini yaphuhliswa edibanisa iingenelo zemisipha yeentsiba zeenkqubo zebhayoloji kunye neempawu ezizodwa ze-SMAs. Olu phononongo luhlola kwaye lwandisa ii-actuators zangaphambili ze-SMA ngokuphuhlisa imodeli yemathematika ye-actuator entsha ngokusekelwe kulungiselelo lwentambo ye-bimodal SMA kwaye luyivavanye ngokulinga. Xa kuthelekiswa nee-drives ezaziwayo ezisekelwe kwi-SMA, amandla okuvuselela e-drive entsha angaphezulu ngokuphindwe kahlanu (ukuya kuthi ga kwi-150 N). Ukulahleka kobunzima obuhambelanayo malunga ne-67%. Iziphumo zohlalutyo lovakalelo lweemodeli zezibalo ziluncedo ekulungiseni iiparameter zoyilo kunye nokuqonda iiparameter eziphambili. Olu phononongo lubonelela ngakumbi nge-multi-level Nth stage drive enokusetyenziswa ukuphucula ngakumbi ii-dynamics. Ii-actuators ze-dipvalerate muscle ezisekelwe kwi-SMA zineendlela ezahlukeneyo zokusetyenziswa, ukusuka kwi-automation yokwakha ukuya kwiinkqubo zokuhambisa amayeza ngokuchanekileyo.
Iinkqubo zebhayoloji, njengezakhiwo zemisipha zezilwanyana ezincancisayo, zinokuvuselela ii-actuators ezininzi ezifihlakeleyo1. Izilwanyana ezincancisayo zinezakhiwo zemisipha ezahlukeneyo, nganye isebenzela injongo ethile. Nangona kunjalo, uninzi lwesakhiwo sezicubu zemisipha yezilwanyana ezincancisayo lunokwahlulwa lube ziindidi ezimbini ezibanzi. I-Parallel kunye ne-pennate. Kwi-hamstrings nakwezinye ii-flexors, njengoko igama lisitsho, imisipha ehambelanayo inee-muscle fibers ezihambelana ne-central tendon. I-chain ye-muscle fibers ibekwe kwaye idityaniswe ngokusebenzayo yi-connective tissue ezizingqongileyo. Nangona ezi zihlunu kuthiwa zinohambo olukhulu (ipesenti yokunciphisa), amandla azo emisipha iyonke anqongophele kakhulu. Ngokwahlukileyo koko, kwi-triceps calf muscle2 (lateral gastrocnemius (GL)3, medial gastrocnemius (GM)4 kunye ne-soleus (SOL)) kunye ne-extensor femoris (quadriceps)5,6 i-pennate muscle tissue ifumaneka kwi-muscle nganye7. Kwisakhiwo se-pinnate, ii-muscle fibers kwi-bipennate musculature zikhona kumacala omabini e-central tendon kwi-oblique engile (pinnate engile). I-Pennate ivela kwigama lesiLatini elithi "penna", elithetha "ipeni", kwaye, njengoko kubonisiwe kumzobo 1 inembonakalo efana neentsiba. Iifayibha zemisipha ye-pennate zimfutshane kwaye zijike kwi-axis ende yemisipha. Ngenxa yesakhiwo se-pinnate, ukuhamba ngokubanzi kwezi zihlunu kuyancipha, okukhokelela kwiindawo ezinqamlezileyo nezinde zenkqubo yokufinyeza. Kwelinye icala, ukusebenza kwezi zihlunu kukhokelela kumandla aphezulu emisipha ngenxa yendlela indawo ye-cross-sectional elinganiswa ngayo. Ke ngoko, kwindawo ethile ye-cross-sectional, izihlunu ze-pennate ziya kuba namandla kwaye ziya kuvelisa amandla aphezulu kunezihlunu ezineefayibha ezifanayo. Amandla aveliswa ziifayibha nganye avelisa amandla emisipha kwinqanaba le-macroscopic kuloo tissue yemisipha. Ukongeza, ineempawu ezikhethekileyo ezifana nokuncitshiswa ngokukhawuleza, ukukhuselwa kumonakalo wokutsalwa, ukuthomalalisa. Iguqula ubudlelwane phakathi kokufakwa kwefayibha kunye nokukhupha amandla emisipha ngokusebenzisa iimpawu ezizodwa kunye nobunzima bejometri yolungiselelo lwefayibha oluhambelana nemigca yesenzo semisipha.
Kuboniswe imizobo yesicwangciso se-SMA-based actuator designs ekhoyo ngokunxulumene ne-bimodal muscular architecture, umzekelo (a), emele ukusebenzisana kwamandla okuchukumisa apho isixhobo esibunjwe ngesandla esiqhutywa ziintambo ze-SMA sifakwe kwi-robot ehambayo enamavili amabini9,10., (b) I-Robotic orbital prosthesis ene-SMA spring-loaded orbital prosthesis ebekwe ngokuchaseneyo. Indawo yeliso le-prosthetic ilawulwa sisignali evela kwimisipha yeliso11, (c) I-SMA actuators zilungele ukusetyenziswa phantsi kwamanzi ngenxa yempendulo yazo ephezulu kunye ne-bandwidth ephantsi. Kolu qwalaselo, ii-actuators ze-SMA zisetyenziselwa ukwenza intshukumo yamaza ngokulinganisa intshukumo yeentlanzi, (d) ii-actuators ze-SMA zisetyenziselwa ukwenza irobhothi yokuhlola i-micro pipe enokusebenzisa umgaqo wokunyakaza kwe-inch worm, olawulwa yintshukumo yeengcingo ze-SMA ngaphakathi kwetshaneli ye-10, (e) ibonisa indlela yeengcingo zemisipha ezidityanisiweyo kunye nokuvelisa amandla okudityaniswa kwizicubu ze-gastrocnemius, (f) ibonisa iingcingo ze-SMA ezicwangciswe ngendlela yeengcingo zemisipha kwisakhiwo semisipha esijikelezileyo.
Ii-Actuators zibe yinxalenye ebalulekileyo yeenkqubo zoomatshini ngenxa yoluhlu olubanzi lwezicelo zazo. Ke ngoko, imfuneko yee-drives ezincinci, ezikhawulezayo nezisebenzayo iba yinto ebalulekileyo. Nangona ziluncedo, ii-drives zemveli ziye zabonakala zibiza kakhulu kwaye zithatha ixesha ukuzigcina. Ii-actuators ze-hydraulic kunye ne-pneumatic ziyinkimbinkimbi kwaye zibiza kakhulu kwaye zinokuguga, iingxaki zokuthambisa kunye nokusilela kwamacandelo. Ukuphendula imfuno, ingqwalasela ikukuphuhlisa ii-actuators ezingabizi kakhulu, ezilungelelanisiweyo ngobukhulu kunye neziphambili ezisekelwe kwizixhobo ezikrelekrele. Uphando oluqhubekayo lujonga ii-actuators ezinee-shape memory alloy (SMA) ukuze zihlangabezane nale mfuno. Ii-actuators ze-hierarchical zahlukile kuba zidibanisa ii-actuators ezininzi ezahlukeneyo kwiinkqubo ezincinci ze-macro scale ukuze zibonelele ngokusebenza okwandisiweyo nokwandiswayo. Kule meko, izicubu zemisipha yomntu ezichazwe apha ngasentla zibonelela ngomzekelo obalaseleyo we-multilayer ye-multilayer actuation enjalo. Uphononongo lwangoku luchaza i-multi-level SMA drive enezinto ezininzi ze-drive (iintambo ze-SMA) ezihambelana ne-fiber orientations ezikhoyo kwimisipha ye-bimodal, nto leyo ephucula ukusebenza kwe-drive iyonke.
Injongo ephambili ye-actuator kukuvelisa amandla oomatshini afana namandla kunye nokususwa ngokuguqula amandla ombane. Ii-alloys zememori yesimo ziluhlu lwezinto "ezikrelekrele" ezinokubuyisela imo yazo kumaqondo obushushu aphezulu. Phantsi kwemithwalo ephezulu, ukwanda kobushushu bentambo ye-SMA kukhokelela ekubuyiselweni kwesimo, okubangela uxinano olukhulu lwamandla okusebenza xa kuthelekiswa nezinto ezahlukeneyo ezikrelekrele ezidityaniswe ngqo. Kwangaxeshanye, phantsi kwemithwalo yoomatshini, ii-SMA ziba brittle. Phantsi kweemeko ezithile, umthwalo ojikelezayo unokufunxa kwaye ukhulule amandla oomatshini, ubonise utshintsho oluguquguqukayo lwemilo. Ezi mpawu zikhethekileyo zenza i-SMA ibe yeyona ifanelekileyo kwiisensors, ukudambisa ukungcangcazela kwaye ngakumbi ii-actuators12. Ngokucinga oku, kubekho uphando oluninzi kwiidrives ezisekwe kwi-SMA. Kufuneka kuqatshelwe ukuba ii-actuators ezisekwe kwi-SMA zenzelwe ukubonelela ngentshukumo yokuguqula kunye neyokujikeleza kwiintlobo ngeentlobo zezicelo13,14,15. Nangona ezinye ii-actuators ezijikelezayo ziye zaphuhliswa, abaphandi banomdla kakhulu kwii-actuators ezingqalileyo. Ezi actuators ezingqalileyo zinokwahlulwa zibe ziintlobo ezintathu ze-actuators: ii-one-dimensional, displacement kunye ne-differential actuators16. Ekuqaleni, ii-hybrid drives zenziwe ngokudibeneyo ne-SMA kunye nezinye ii-conventional drives. Omnye umzekelo onjalo we-SMA-based hybrid linear actuator kukusetyenziswa kwentambo ye-SMA ene-DC motor ukubonelela ngamandla okukhupha amalunga ne-100 N kunye nokufuduka okubalulekileyo17.
Enye yezinto zokuqala ezenzeka kwiidrives ezisekelwe ngokupheleleyo kwi-SMA yayiyi-SMA parallel drive. Kusetyenziswa iintambo ezininzi ze-SMA, i-SMA-based parallel drive yenzelwe ukwandisa amandla ombane edrive ngokubeka zonke iintambo ze-SMA18 ngendlela efanayo. Uqhagamshelo oluhambelanayo lwee-actuators aludingi nje kuphela amandla angaphezulu, kodwa lukwanciphisa amandla okukhupha ucingo olunye. Enye ingxaki yee-actuators ezisekelwe kwi-SMA kukuhamba okulinganiselweyo ezinokukufezekisa. Ukusombulula le ngxaki, kwenziwa umqadi wekhebula le-SMA oqulathe umqadi oguquguqukayo ojikajikayo ukwandisa ukufuduka kunye nokufezekisa intshukumo ethe tye, kodwa awuzange uvelise amandla aphezulu19. Izakhiwo ezithambileyo eziguquguqukayo kunye namalaphu eerobhothi ezisekelwe kwii-alloys zememori yesimo ziye zaphuhliswa ikakhulu ukuze kuphuculwe impembelelo20,21,22. Kwizicelo apho kufuneka isantya esiphezulu, iipompo eziqhutywayo ezixineneyo ziye zaxelwa kusetyenziswa ii-SMA zefilimu ezithe tyaba kwizicelo eziqhutywa yi-micropump23. Ukuphindaphinda kokuqhuba kwe-membrane yefilimu ethe tyaba ye-SMA yinto ephambili ekulawuleni isantya somqhubi. Ke ngoko, ii-SMA linear motors zinempendulo engcono enamandla kunee-SMA spring okanye rod motors. Iirobhothi ezithambileyo kunye netekhnoloji yokubamba zezinye iindlela ezimbini ezisebenzisa ii-actuators ezisekwe kwi-SMA. Umzekelo, ukuze kuthathelwe indawo i-actuator eqhelekileyo esetyenziswa kwi-25 N space clamp, kwaphuhliswa i-shape memory alloy parallel actuator 24. Kwelinye icala, i-actuator ethambileyo ye-SMA yenziwe ngokusekelwe kwintambo ene-matrix efakwe ngaphakathi ekwaziyo ukuvelisa amandla aphezulu okutsala angama-30 N. Ngenxa yeempawu zazo zoomatshini, ii-SMA zikwasetyenziselwa ukuvelisa ii-actuators ezilinganisa iziganeko zebhayoloji. Olunye uphuhliso olunjalo luquka irobhothi yeeseli ezili-12 eyi-biomimetic yento ephilayo efana ne-earthworm ene-SMA ukuvelisa intshukumo ye-sinusoidal ukuya kutshaya26,27.
Njengoko bekutshiwo ngaphambili, kukho umda kumandla aphezulu anokufunyanwa kwii-actuators ezisekwe kwi-SMA ezikhoyo. Ukujongana nale ngxaki, olu phononongo lubonisa isakhiwo semisipha ye-bimodal ye-biomimetic. Iqhutywa yi-shape memory alloy wire. Ibonelela ngenkqubo yokwahlulahlula equka iintambo ezininzi ze-shape memory alloy. Ukuza kuthi ga ngoku, akukho zi-actuators ezisekwe kwi-SMA ezinesakhiwo esifanayo ezixeliweyo kwiincwadi. Le nkqubo ikhethekileyo nentsha esekelwe kwi-SMA yaphuhliswa ukuze ifunde indlela yokuziphatha kwe-SMA ngexesha lokulungelelaniswa kwemisipha ye-bimodal. Xa kuthelekiswa nee-actuators ezisekwe kwi-SMA ezikhoyo, injongo yolu phononongo yayikukudala i-actuator ye-biomimetic dipvalerate ukuvelisa amandla aphezulu kakhulu ngomthamo omncinci. Xa kuthelekiswa nee-drives ze-stepper motor eziqhutywa yi-stepper ezisetyenziswa kwiinkqubo zolawulo lwe-HVAC, uyilo lwe-bimodal drive olucetywayo lwe-SMA lunciphisa ubunzima be-drive mechanism ngama-67%. Kula magama alandelayo, amagama athi "muscle" kunye "drive" asetyenziswa ngokutshintshana. Olu phononongo luphanda ukulinganisa kwe-multiphysics ye-drive enjalo. Indlela yokuziphatha kweenkqubo ezinjalo ifundwe ngeendlela zovavanyo kunye nohlalutyo. Ukusasazwa kwamandla kunye nobushushu kuphandwe ngakumbi kwi-voltage yokufaka ye-7 V. Emva koko, uhlalutyo lwe-parametric lwenziwa ukuze kuqondwe ngcono ubudlelwane phakathi kweeparameter eziphambili kunye namandla okukhupha. Okokugqibela, ii-actuators ze-hierarchical ziye zabonwa kwaye iziphumo zenqanaba le-hierarchical ziye zacetyiswa njengendawo enokubakho kwixesha elizayo yee-actuators ezingezizo zemagnethi kwizicelo ze-prosthetic. Ngokweziphumo zezifundo ezikhankanyiweyo ngasentla, ukusetyenziswa koyilo lwesigaba esinye kuvelisa amandla ubuncinane amaxesha amane ukuya kwamahlanu aphezulu kunee-actuators ezisekelwe kwi-SMA ezixeliweyo. Ukongeza, amandla okuqhuba afanayo aveliswa yi-multi-level multi-level drive abonakaliswe ukuba angaphezu kwamaxesha alishumi kunee-drives ze-SMA eziqhelekileyo. Olu phononongo emva koko lubika iiparameter eziphambili kusetyenziswa uhlalutyo lovakalelo phakathi koyilo olwahlukeneyo kunye neenguqu zokufaka. Ubude bokuqala bentambo ye-SMA (\(l_0\)), i-pinnate angle (\(\alpha\)) kunye nenani lee-single string (n) kwi-strand nganye nganye zinefuthe elibi kakhulu kubukhulu bamandla okuqhuba, ngelixa i-voltage yokufaka (amandla) ivele yahambelana kakuhle.
Intambo ye-SMA ibonisa isiphumo sememori yesimo (i-SME) esibonwa kusapho lwee-alloys ze-nickel-titanium (i-Ni-Ti). Ngokwesiqhelo, ii-SMA zibonisa izigaba ezibini ezixhomekeke kubushushu: isigaba sobushushu obuphantsi kunye nesigaba sobushushu obuphezulu. Zombini izigaba zineempawu ezizodwa ngenxa yokubakho kwezakhiwo ezahlukeneyo zekristale. Kwisigaba se-austenite (isigaba sobushushu obuphezulu) esikhoyo ngaphezulu kobushushu bokuguqulwa, izinto zibonisa amandla aphezulu kwaye aziguquguquki kakuhle phantsi komthwalo. I-alloy isebenza njengentsimbi engagqwaliyo, ngoko iyakwazi ukumelana noxinzelelo oluphezulu lwe-activation. Isebenzisa olu phawu lwee-alloys ze-Ni-Ti, iingcingo ze-SMA zithe tyaba ukuze zenze i-actuator. Iimodeli ezifanelekileyo zohlalutyo ziyenziwa ukuze kuqondwe indlela esisiseko yokuziphatha kobushushu be-SMA phantsi kwempembelelo yeeparameter ezahlukeneyo kunye neejometri ezahlukeneyo. Kufunyenwe isivumelwano esihle phakathi kweziphumo zovavanyo kunye nohlalutyo.
Kwenziwe uphando lovavanyo kwiprototype eboniswe kwiFig. 9a ukuvavanya ukusebenza kwe-bimodal drive esekelwe kwi-SMA. Ezimbini zezi mpawu, amandla aveliswa yi-drive (amandla emisipha) kunye nobushushu be-SMA wire (ubushushu be-SMA), zilinganiswe ngovavanyo. Njengoko umahluko we-voltage usanda kubude bonke be-wire kwi-drive, ubushushu be-wire buyanda ngenxa yesiphumo sokufudumeza seJoule. I-input voltage isetyenziswe kwimijikelo emibini ye-10-s (eboniswe njengamachaphaza abomvu kwiFig. 2a, b) kunye nexesha lokupholisa le-15-s phakathi komjikelo ngamnye. Amandla okuvimba alinganiswe kusetyenziswa i-piezoelectric strain gauge, kwaye ukusasazwa kobushushu be-SMA wire kwajongwa ngexesha langempela kusetyenziswa ikhamera ye-LWIR ye-high-resolution yesayensi (jonga iimpawu zezixhobo ezisetyenzisiweyo kwiTheyibhile 2). ibonisa ukuba ngexesha le-high voltage, ubushushu be-wire buyanda ngokungaqhelekanga, kodwa xa kungekho mbane ohambayo, ubushushu be-wire buyaqhubeka nokwehla. Kwisetingi yovavanyo yangoku, ubushushu bentambo ye-SMA behle ngexesha lokupholisa, kodwa bebusengaphezulu kobushushu obuqhelekileyo. Kumfanekiso 2e ubonisa umfanekiso weqondo lobushushu kwintambo ye-SMA ethathwe kwikhamera ye-LWIR. Kwelinye icala, kumfanekiso 2a ubonisa amandla okuvimba aveliswa yinkqubo yokuqhuba. Xa amandla emisipha edlula amandla okubuyisela entwasahlobo, ingalo eshukumayo, njengoko kubonisiwe kuMfanekiso 9a, iqala ukuhamba. Kwangoko xa i-activation iqala, ingalo eshukumayo idibana ne-sensor, idala amandla omzimba, njengoko kubonisiwe kumfanekiso 2c, d. Xa ubushushu obuphezulu busondele kwi \(84\,^{\circ}\hbox {C}\), amandla aphezulu abonwayo yi-105 N.
Igrafu ibonisa iziphumo zovavanyo lobushushu bentambo ye-SMA kunye namandla aveliswa yi-actuator ye-bimodal esekwe kwi-SMA ngexesha lemijikelo emibini. I-voltage yokufaka isetyenziswa kwimijikelo emibini yemizuzwana eli-10 (eboniswe njengamachaphaza abomvu) kunye nexesha lokuphola lemizuzwana eli-15 phakathi komjikelo ngamnye. Intambo ye-SMA esetyenzisiweyo kwimijikelo yayiyintambo yeFlexinol enobubanzi obuyi-0.51 mm evela kwi-Dynalloy, Inc. (a) Igrafu ibonisa amandla ovavanyo afunyenwe kwimijikelo emibini, (c, d) ibonisa imizekelo emibini ezimeleyo yesenzo se-actuators zengalo ezihambayo kwi-transducer ye-PACEline CFT/5kN piezoelectric force ye-transducer, (b) igrafu ibonisa ubushushu obuphezulu bentambo ye-SMA yonke ngexesha lemijikelo emibini, (e) ibonisa umfanekiso wobushushu othathwe kwintambo ye-SMA kusetyenziswa ikhamera yesoftware ye-FLIR ResearchIR LWIR. Iiparameter zejometri ezithathelwe ingqalelo kwimijikelo zinikwe kwiTheyibhile yokuqala.
Iziphumo zokulinganisa zemodeli yezibalo kunye neziphumo zovavanyo zithelekiswa phantsi kwemeko yevolthi yokufaka ye-7V, njengoko kubonisiwe kwiFig.5. Ngokweziphumo zohlalutyo lweparametric kunye nokuthintela ukuba kungenzeka ukuba intambo ye-SMA igqithise kakhulu, amandla e-11.2 W anikwe i-actuator. Umbane we-DC ocwangcisiweyo wasetyenziswa ukubonelela nge-7V njengevolthi yokufaka, kwaye umbane we-1.6A walinganiswa kuyo yonke intambo. Amandla aveliswa yi-drive kunye nobushushu be-SDR ayanda xa kusetyenziswa umbane. Ngevolthi yokufaka ye-7V, amandla aphezulu okukhupha afunyenwe kwiziphumo zokulinganisa kunye neziphumo zovavanyo zomjikelo wokuqala yi-78 N kunye ne-96 N, ngokwahlukeneyo. Kumjikelo wesibini, amandla aphezulu okukhupha eziphumo zokulinganisa kunye neziphumo zovavanyo yayiyi-150 N kunye ne-105 N, ngokwahlukeneyo. Umahluko phakathi kokulinganiswa kwamandla okuvala kunye nedatha yovavanyo unokubangelwa yindlela esetyenzisiweyo ukulinganisa amandla okuvala. Iziphumo zovavanyo eziboniswe kwiFig. I-5a ihambelana nokulinganiswa kwamandla okutshixa, okwathi ke kwalinganiswa xa i-drive shaft yayidibana ne-PACEline CFT/5kN piezoelectric force transducer, njengoko kubonisiwe kumfanekiso 2s. Ke ngoko, xa i-drive shaft ingadibananga ne-force sensor ekuqaleni kwendawo yokupholisa, amandla ngoko nangoko aba zero, njengoko kubonisiwe kumfanekiso 2d. Ukongeza, ezinye iiparameter ezichaphazela ukwakheka kwamandla kwimijikelo elandelayo zixabiso lexesha lokupholisa kunye ne-coefficient yokudluliselwa kobushushu obuhambelanayo kumjikelo odlulileyo. Ukusuka kumfanekiso 2b, kunokubonwa ukuba emva kwexesha lokupholisa lemizuzwana eli-15, intambo ye-SMA ayizange ifikelele kubushushu begumbi kwaye ke ngoko yayinobushushu obuphezulu bokuqala (\(40\,^{\circ }\hbox {C}\)) kumjikelo wesibini wokuqhuba xa kuthelekiswa nomjikelo wokuqala (\(25\, ^{\circ}\hbox {C}\)). Ngoko ke, xa kuthelekiswa nomjikelo wokuqala, ubushushu bentambo ye-SMA ngexesha lomjikelo wesibini wokufudumeza bufikelela kubushushu bokuqala be-austenite (\(A_s\)) ngaphambili kwaye buhlala kwixesha lotshintsho ixesha elide, nto leyo ebangela uxinzelelo kunye namandla. Kwelinye icala, ukusasazwa kobushushu ngexesha lomjikelo wokufudumeza nokupholisa ofunyenwe kwiimvavanyo kunye neesimulations kunokufana okuphezulu kwimizekelo evela kuhlalutyo lwe-thermographic. Uhlalutyo oluthelekisayo lwedatha yobushushu bentambo ye-SMA evela kwiimvavanyo kunye neesimulations lubonise ukuhambelana ngexesha lomjikelo wokufudumeza nokupholisa kwaye ngaphakathi kokunyamezelana okwamkelekileyo kwedatha yovavanyo. Ubushushu obuphezulu bentambo ye-SMA, obufunyenwe kwiziphumo zokulinganisa kunye neemvavanyo zomjikelo wokuqala, yi \(89\,^{\circ }\hbox {C}\) kunye \(75\,^{\circ }\hbox {C }\, ngokulandelanayo ), kwaye kumjikelo wesibini ubushushu obuphezulu bentambo ye-SMA yi \(94\,^{\circ }\hbox {C}\) kunye \(83\,^{\circ }\ hbox {C}\). Imodeli ephuhliswe ngokusisiseko iqinisekisa isiphumo sesiphumo sememori yesimo. Indima yokudinwa kunye nokugqithisa kakhulu ayizange iqwalaselwe kolu phononongo. Kwixesha elizayo, imodeli iya kuphuculwa ukuze ibandakanye imbali yoxinzelelo lwentambo ye-SMA, okwenza ifaneleke ngakumbi kwizicelo zobunjineli. Amandla okukhupha idrayivu kunye nezicwangciso zobushushu ze-SMA ezifunyenwe kwibhloko yeSimulink zingaphakathi kokunyamezela okuvumelekileyo kwedatha yovavanyo phantsi kwemeko ye-input voltage pulse ye-7 V. Oku kuqinisekisa ukuchaneka kunye nokuthembeka kwemodeli yezibalo ephuhlisiwe.
Imodeli yezibalo yaphuhliswa kwindawo yeMathWorks Simulink R2020b kusetyenziswa ii-equation ezisisiseko ezichazwe kwicandelo leeNdlela. Kumzobo 3b ubonisa umzobo webhloko wemodeli yezibalo yeSimulink. Imodeli yenziwe ngendlela ye-7V input voltage pulse njengoko kubonisiwe kuMzobo 2a, b. Amaxabiso eeparameter ezisetyenzisiweyo kumbumbulu adweliswe kwiTheyibhile 1. Iziphumo zombumbulu weenkqubo zexesha elifutshane ziboniswe kuMzobo 1 no-1. Imifanekiso 3a no-4. Kumzobo 4a, b ubonisa i-voltage ebangelwayo kwi-SMA wire kunye namandla aveliswa yi-actuator njengomsebenzi wexesha. Ngexesha lokuguqulwa okungasemva (ukufudumeza), xa ubushushu bentambo ye-SMA, \(T < A_s^{\prime}\) (ubushushu bokuqala kwesigaba se-austenite esiguqulweyo nguxinzelelo), izinga lotshintsho lweqhekeza lomthamo we-martensite (\(\dot{\xi }\)) liya kuba zero. Ngexesha lokuguqulwa okungasemva (ukufudumeza), xa ubushushu bentambo ye-SMA, \(T < A_s^{\prime}\) (ubushushu bokuqala kwesigaba se-austenite esiguqulweyo nguxinzelelo), izinga lotshintsho lweqhekeza lomthamo we-martensite (\(\dot{\ xi }\)) liya kuba zero. Во время обратного превращения (нагрева), когда температура проволоки SMA, \(T < A_s^{\prime}\) (температура начала аустенитной модинация напряжением), скорость изменения объемной доли мартенсита (\(\dot{\ xi }\)) будет равно нулю. Ngexesha lokuguqulwa okungasemva (ukufudumeza), xa ubushushu bentambo ye-SMA, \(T < A_s^{\prime}\) (ubushushu bokuqala be-austenite obuguqulweyo nguxinzelelo), izinga lotshintsho lweqhekeza lomthamo we-martensite (\(\dot{\ xi }\ )) liya kuba ngu-zero.在反向转变（加热）过程中，当SMA 线温度\(T < A_s^{\inkulu}\)（应力修正奥氏体相起始温度）时，马氏体体积分数的变化率（\(\xi\)在 反向 转变 （加热） 中, 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. Ngexesha lokuguqulwa okungasemva (ukufudumeza) kubushushu bentambo ye-SMA \(T < A_s^{\prime}\) (ubushushu be-nucleation yesigaba se-austenite, esilungisiweyo ngenxa yoxinzelelo), izinga lotshintsho kwiqhezu levolumu ye-martensite (\( \dot{\ xi }\)) liya kulingana no-zero.Ngoko ke, izinga lotshintsho loxinzelelo (\(\dot{\sigma}\)) liza kuxhomekeka kwizinga loxinzelelo (\(\dot{\epsilon}\)) kunye ne-gradient yobushushu (\(\dot{T} \) ) kuphela ngokusebenzisa i-equation (1). Nangona kunjalo, njengoko intambo ye-SMA isanda kubushushu kwaye iwela (\(A_s^{\prime}\)), isigaba se-austenite siqala ukwakheka, kwaye (\(\dot{\xi}\)) sithathwa njengexabiso elinikiweyo le-equation (3). Ke ngoko, izinga lotshintsho lwe-voltage (\(\dot{\sigma}\)) lilawulwa ngokudibeneyo yi-\(\dot{\epsilon}, \dot{T}\) kunye ne-\(\dot{\xi}\) zilingana ne-equation (1). Oku kuchaza utshintsho lwe-gradient olubonwa kwiimephu zoxinzelelo ezitshintsha-tshintsha ixesha kunye namandla ngexesha lomjikelo wobushushu, njengoko kubonisiwe kwiFig. 4a, b.
(a) Isiphumo sokulinganisa esibonisa ukusasazwa kobushushu kunye nobushushu bokuhlangana obubangelwa luxinzelelo kwi-actuator ye-divalerate esekwe kwi-SMA. Xa ubushushu bentambo buwela ubushushu botshintsho lwe-austenite kwisigaba sokufudumeza, ubushushu botshintsho lwe-austenite oluguquliweyo buqala ukwanda, kwaye ngokufanayo, xa ubushushu bentambo buwela ubushushu botshintsho lwe-martensitic kwisigaba sokuphola, ubushushu botshintsho lwe-martensitic buyancipha. I-SMA yokubonisa uhlalutyo lwenkqubo yokuqalisa. (Ukuze ufumane umbono oneenkcukacha wenkqubo nganye engaphantsi yemodeli yeSimulink, jonga icandelo lesihlomelo kwifayile eyongezelelweyo.)
Iziphumo zohlalutyo lokusasazwa kweeparameter ezahlukeneyo ziboniswa kwimijikelo emibini ye-voltage yokufaka ye-7V (imijikelo yokufudumeza yemizuzwana eli-10 kunye nemijikelo yokuphola yemizuzwana eli-15). Ngelixa u-(ac) kunye no-(e) bebonisa usasazo ngokuhamba kwexesha, kwelinye icala, (d) kunye no-(f) bebonisa usasazo kunye nobushushu. Kwiimeko zokufaka ezifanelekileyo, uxinzelelo oluphezulu olubonwayo yi-106 MPa (ngaphantsi kwe-345 MPa, amandla okukhupha intambo), amandla yi-150 N, ukuhanjiswa okuphezulu yi-270 µm, kwaye iqhekeza elincinci le-martensitic volume yi-0.91. Kwelinye icala, utshintsho kuxinzelelo kunye notshintsho kwiqhekeza levolumu ye-martensite kunye nobushushu ziyafana neempawu ze-hysteresis.
Ingcaciso efanayo isebenza kutshintsho oluthe ngqo (ukupholisa) ukusuka kwisigaba se-austenite ukuya kwisigaba se-martensite, apho ubushushu be-SMA wire (T) kunye nobushushu bokugqibela besigaba se-martensite esiguqulweyo ngoxinzelelo (\(M_f^{\prime}\ )) bubalasele kakhulu. Kumfanekiso 4d,f ubonisa utshintsho kuxinzelelo olubangelwayo (\(\sigma\)) kunye nenxalenye yevolumu ye-martensite (\(\xi\)) kwintambo ye-SMA njengomsebenzi wotshintsho kubushushu bentambo ye-SMA (T), kuzo zombini iijikelo zokuqhuba. Kumfanekiso 3a ubonisa utshintsho kubushushu bentambo ye-SMA ngokuhamba kwexesha kuxhomekeke kwi-introl voltage pulse. Njengoko kunokubonwa kumfanekiso, ubushushu bentambo buyaqhubeka nokwanda ngokubonelela ngomthombo wobushushu kwi-zero voltage kunye nokupholisa okulandelayo kwe-convective. Ngexesha lokufudumeza, ukuguqulwa kwakhona kwe-martensite ukuya kwisigaba se-austenite kuqala xa ubushushu be-SMA wire (T) buwela ubushushu be-austenite nucleation obulungiswe ngoxinzelelo (\(A_s^{\prime}\)). Ngeli nqanaba, intambo ye-SMA iyacinezelwa kwaye i-actuator ivelisa amandla. Kwakhona ngexesha lokuphola, xa ubushushu be-SMA wire (T) buwela ubushushu be-nucleation besigaba se-martensite esiguqulwe ngoxinzelelo (\(M_s^{\prime}\)) kukho utshintsho oluhle ukusuka kwisigaba se-austenite ukuya kwisigaba se-martensite. Amandla okuqhuba ayancipha.
Izinto eziphambili ezisemgangathweni ze-bimodal drive ezisekelwe kwi-SMA zinokufunyanwa kwiziphumo zokulinganisa. Kwimeko yokufaka i-voltage pulse, ubushushu bentambo ye-SMA buyanda ngenxa yesiphumo sokufudumeza seJoule. Ixabiso lokuqala le-martensite volume fraction (\(\xi\)) limiselwe kwi-1, kuba izinto ziqala zikwisigaba se-martensitic ngokupheleleyo. Njengoko intambo iqhubeka nokufudumala, ubushushu bentambo ye-SMA budlula ubushushu be-austenite nucleation obulungisiweyo ngoxinzelelo \(A_s^{\prime}\), okubangela ukwehla kwe-martensite volume fraction, njengoko kubonisiwe kuMfanekiso 4c. Ukongeza, kumzobo 4e kubonisa ukusasazwa kwe-strokes ye-actuator ngexesha, nakumzobo 5 - amandla okuqhuba njengomsebenzi wexesha. Inkqubo enxulumeneyo yee-equation ibandakanya ubushushu, i-martensite volume fraction, kunye noxinzelelo oluvela kwintambo, okubangela ukushwabana kwentambo ye-SMA kunye namandla aveliswa yi-actuator. Njengoko kubonisiwe kumzobo. Utshintsho lwe-voltage lwe-4d,f, olunobushushu kunye notshintsho lwe-martensite volume fraction olunobushushu luhambelana neempawu ze-hysteresis ze-SMA kwimeko elinganisiweyo kwi-7 V.
Uthelekiso lweeparamitha zokuqhuba lufunyenwe ngovavanyo kunye nokubala okuhlalutyayo. Iintambo zifakwe kwi-pulsed input voltage ye-7 V imizuzwana eli-10, zaze zapholiswa imizuzwana eli-15 (isigaba sokupholisa) kwimijikelo emibini. I-angle ye-pinnate imiselwe kwi-\(40^{\circ}\) kwaye ubude bokuqala bentambo ye-SMA kumlenze ngamnye we-pin bumiselwe kwi-83mm. (a) Ukulinganisa amandla okuqhuba ngeseli yomthwalo (b) Ukujonga ubushushu bentambo ngekhamera ye-thermal infrared.
Ukuze kuqondwe impembelelo yeeparameters zomzimba kumandla aveliswa yi-drive, kwenziwe uhlalutyo lovakalelo lwemodeli yezibalo kwiiparameters zomzimba ezikhethiweyo, kwaye iiparameters zahlelwa ngokwempembelelo yazo. Okokuqala, isampuli yeeparameters zemodeli yenziwe kusetyenziswa imigaqo yoyilo lovavanyo elandela usasazo olufanayo (jonga iCandelo elongezelelweyo kuHlalutyo loBuchule). Kule meko, iiparameters zemodeli ziquka i-input voltage (\(V_{in}\)), ubude bentambo ye-SMA yokuqala (\(l_0\)), i-triangle angle (\(\alpha\)), i-bias spring constant (\( K_x\ )), i-convective heat transfer coefficient (\(h_T\)) kunye nenani lamasebe e-unimodal (n). Kwinyathelo elilandelayo, amandla emisipha encotsheni akhethwe njengemfuneko yoyilo lwesifundo kwaye iziphumo ze-parametric zeseti nganye yeenguqu kumandla zafunyanwa. Iiploti ze-tornado zohlalutyo lobuntununtunu zafunyanwa kwii-coefficients zolwalamano kwiparameter nganye, njengoko kuboniswe kwiFig. 6a.
(a) Amaxabiso e-coefficient yokuhambelana kweeparamitha zemodeli kunye nempembelelo yazo kumandla aphezulu okukhupha amaqela angama-2500 ahlukileyo kwiiparamitha zemodeli engentla aboniswe kwiploti yenkanyamba. Igrafu ibonisa ukuhambelana kwerenki kwezalathisi ezininzi. Kucacile ukuba \(V_{in}\) yeyona parameter kuphela enolwalamano oluhle, kwaye \(l_0\) yiparameter enolwalamano olubi oluphezulu. Impembelelo yeeparamitha ezahlukeneyo kwiindidi ezahlukeneyo kumandla emisipha ephezulu iboniswe kwi (b, c). \(K_x\) isusela kwi-400 ukuya kwi-800 N/m kwaye i-n isusela kwi-4 ukuya kwi-24. I-Voltage (\(V_{in}\)) itshintshile ukusuka kwi-4V ukuya kwi-10V, ubude bentambo (\(l_{0} \)) itshintshile ukusuka kwi-40 ukuya kwi-100 mm, kwaye i-angle yomsila (\ (\alpha \)) yahluka ukusuka kwi \ (20 - 60 \, ^ {\circ }\).
Kumfanekiso 6a ubonisa iploti yenkanyamba yee-coefficients ezahlukeneyo zokunxibelelana kwiparameter nganye eneemfuno zoyilo lwamandla okuqhuba okuphezulu. Ukusuka kumfanekiso 6a kunokubonwa ukuba iparameter ye-voltage (\(V_{in}\)) inxulumene ngokuthe ngqo namandla aphezulu okukhupha, kwaye i-coefficient yokudlulisa ubushushu eguqukayo (\(h_T\)), i-flame angle (\( \alpha\)), i-displacement spring constant ( \(K_x\)) inxulumene kakubi namandla okukhupha kunye nobude bokuqala (\(l_0\)) bentambo ye-SMA, kwaye inani lamasebe e-unimodal (n) libonisa ulwalamano oluchaseneyo oluqinileyo Kwimeko yolwalamano oluthe ngqo Kwimeko yexabiso eliphezulu le-coefficient yolwalamano lwe-voltage (\(V_ {in}\)) ibonisa ukuba le parameter inefuthe elikhulu kwimveliso yamandla. Olunye uhlalutyo olufanayo lulinganisa amandla e-peak ngokuvavanya isiphumo seeparameter ezahlukeneyo kwiindibaniselwano ezahlukeneyo zeendawo ezimbini zokubala, njengoko kubonisiwe kuMfanekiso 6b, c. \(V_{in}\) kunye \(l_0\), \(\alpha\) kunye \(l_0\) zinepateni ezifanayo, kwaye igrafu ibonisa ukuba \(V_{in}\) kunye \(\alpha\ ) kunye \(\alpha\) zinepateni ezifanayo. Amaxabiso amancinci e \(l_0\) abangela amandla aphezulu encochoyi. Ezinye iiploti ezimbini ziyahambelana noMfanekiso 6a, apho u-n kunye \(K_x\) zidibene kakubi kwaye \(V_{in}\) zidibene kakuhle. Olu hlalutyo lunceda ukuchaza nokulungisa iiparameter ezichaphazelayo apho amandla okukhupha, istroke kunye nokusebenza kakuhle kwenkqubo yedrayivu zinokuhlengahlengiswa ngokweemfuno kunye nokusetyenziswa.
Umsebenzi wophando lwangoku uzisa kwaye uphanda ii-hierarchical drives ezine-N levels. Kwi-hierarchy yamanqanaba amabini, njengoko kubonisiwe kwiFig. 7a, apho endaweni ye-SMA nganye ye-actuator yenqanaba lokuqala, kufezekiswa ulungiselelo lwe-bimodal, njengoko kubonisiwe kwiFig. 9e. KwiFig. 7c ibonisa indlela i-SMA wire ejikelezwe ngayo ingalo eshukumayo (ingalo encedisayo) ehamba kuphela kwicala elide. Nangona kunjalo, ingalo eshukumayo ephambili iyaqhubeka nokuhamba ngendlela efanayo nengalo eshukumayo ye-1st stage multi-stage actuator. Ngokwesiqhelo, i-N-stage drive yenziwa ngokutshintsha i-\(N-1\) stage SMA wire nge-first-stage drive. Ngenxa yoko, isebe ngalinye lixelisa i-first stage drive, ngaphandle kwesebe elibambe i-wire ngokwayo. Ngale ndlela, izakhiwo ezifakwe iindlwane zinokwenziwa ezidala amandla amakhulu amaxesha amaninzi kune-primary drives. Kolu phononongo, kwinqanaba ngalinye, ubude be-SMA wire obusebenzayo obuyi-1 m buthathelwe ingqalelo, njengoko kubonisiwe kwifomathi yetafile kwiFig. 7d. Umbane ohamba ngentambo nganye kuyilo ngalunye lwe-unimodal kunye ne-prestress kunye ne-voltage ephumayo kwicandelo ngalinye le-SMA wire ziyafana kwinqanaba ngalinye. Ngokwemodeli yethu yohlalutyo, amandla okukhupha ahambelana kakuhle nenqanaba, ngelixa ukufuduka kunxulumene kakubi. Kwangaxeshanye, bekukho ukurhweba phakathi kokufuduka kunye namandla emisipha. Njengoko kubonwe kumzobo 7b, ngelixa amandla aphezulu efezekiswa kwinani elikhulu leeleya, ukufuduka okukhulu kubonwa kwileya esezantsi. Xa inqanaba le-hierarchy limiselwe kwi-\(N=5\), amandla emisipha aphezulu angama-2.58 kN afunyenwe ngemivimbo emibini ebonwe \(\upmu\)m. Kwelinye icala, i-drive yesigaba sokuqala ivelisa amandla angama-150 N kwi-stroke engama-277 \(\upmu\)m. Ii-actuators zamanqanaba amaninzi ziyakwazi ukulinganisa izihlunu zebhayoloji zokwenyani, apho izihlunu zokwenziwa ezisekwe kwi-alloys zememori yesimo ziyakwazi ukuvelisa amandla aphezulu kakhulu ngeentshukumo ezichanekileyo nezicothayo. Imida yale design incinci kukuba njengoko uluhlu lwemisebenzi lukhula, intshukumo iyancipha kakhulu kwaye ubunzima benkqubo yokuvelisa i-drive buyanda.
(a) Inkqubo ye-actuator ye-layered shape alloy linear actuator enamanqanaba amabini (\(N=2\)) iboniswa kulungiselelo lwe-bimodal. Imodeli ecetywayo ifezekiswa ngokutshintsha ucingo lwe-SMA kwi-actuator enemigangatho yesigaba sokuqala ngesinye i-actuator enemigangatho yesigaba esinye. (c) Ulwakhiwo oluguquguqukileyo lwe-actuator yesigaba sesibini esinemigangatho emininzi. (b) Ukusasazwa kwamandla kunye nokuhanjiswa ngokuxhomekeke kwinani lamanqanaba kuchaziwe. Kufunyenwe ukuba amandla aphezulu e-actuator ahambelana kakuhle nenqanaba lesikali kwigrafu, ngelixa i-stroke ihambelana kakubi nenqanaba lesikali. I-current kunye ne-pre-voltage kwintambo nganye zihlala zingaguquki kuzo zonke iinqanaba. (d) Itheyibhile ibonisa inani lee-taps kunye nobude bentambo ye-SMA (ifayibha) kwinqanaba ngalinye. Iimpawu zeentambo ziboniswe yi-index 1, kwaye inani lamasebe esibini (elinye eliqhagamshelwe kumlenze oyintloko) liboniswa linani elikhulu kwi-subscript. Umzekelo, kwinqanaba lesi-5, \(n_1\) ibhekisa kwinani leentambo ze-SMA ezikhoyo kwisakhiwo ngasinye se-bimodal, kwaye \(n_5\) ibhekisa kwinani leemilenze ezincedisayo (enye iqhagamshelwe kumlenze oyintloko).
Iindlela ezahlukeneyo ziye zacetyiswa ngabaphandi abaninzi ukuze babonise indlela yokuziphatha kwe-SMAs ngememori yesimo, exhomekeke kwiipropati ze-thermomechanical ezihamba notshintsho olukhulu kwisakhiwo sekristale oluhambelana notshintsho lwesigaba. Ukwenziwa kweendlela zokwakha kuyinkimbinkimbi ngokwemvelo. Eyona modeli ye-phenomenological esetyenziswa kakhulu icetywayo yiTanaka28 kwaye isetyenziswa kakhulu kwizicelo zobunjineli. Imodeli ye-phenomenological ecetywayo yiTanaka [28] icinga ukuba iqhekeza levolumu ye-martensite ngumsebenzi we-exponential wobushushu kunye noxinzelelo. Kamva, uLiang noRogers29 kunye noBrinson30 bacetyisa imodeli apho i-phase transition dynamics yayithathwa njengomsebenzi we-cosine we-voltage kunye nobushushu, kunye notshintsho oluncinci kwimodeli. UBecker noBrinson bacebise imodeli ye-kinetic esekelwe kwidayagram yesigaba ukubonakalisa indlela yokuziphatha kwezixhobo ze-SMA phantsi kweemeko zokulayisha ezingacwangciswanga kunye notshintsho oluncinci. UBanerjee32 usebenzisa indlela ye-Bekker kunye ne-Brinson31 phase diagram dynamics ukulinganisa i-degree enye ye-freedom manipulator eyenziwe ngu-Elahinia kunye no-Ahmadian33. Iindlela zeKinetic ezisekelwe kwizazobe zesigaba, eziqwalasela utshintsho olungelulo lwe-monotonic kwi-voltage kunye nobushushu, kunzima ukuzisebenzisa kwizicelo zobunjineli. I-Elakhinia kunye ne-Ahmadian zitsalela ingqalelo kwezi ntsilelo zeemodeli ze-phenomenological ezikhoyo kwaye zicebisa imodeli ye-phenomenological eyandisiweyo yokuhlalutya nokuchaza indlela yokuziphatha kwememori yesimo phantsi kwayo nayiphi na imeko enzima yokulayisha.
Imodeli yolwakhiwo lwentambo ye-SMA inika uxinzelelo (\(\sigma\)), uxinzelelo (\(\epsilon\)), ubushushu (T), kunye nenxalenye yevolumu ye-martensite (\(\xi\)) yentambo ye-SMA. Imodeli ye-phenomenological constitutive yaqala ukucetyiswa nguTanaka28 kwaye kamva yamkelwe nguLiang29 kunye noBrinson30. I-derivative ye-equation inesimo:
apho i-E yi-modulus ye-SMA Young exhomekeke kwisigaba efunyenwe kusetyenziswa i-\(\displaystyle E=\xi E_M + (1-\xi )E_A\) kunye ne-\(E_A\) kunye ne-\(E_M\) emele i-modulus kaYoung zii-austenitic kunye ne-martensitic phases, ngokulandelelana, kwaye i-coefficient of thermal expansion imelwe yi-\(\theta _T\). I-phase transition contribution factor yi-\(\Omega = -E \epsilon _L\) kunye ne-\(\epsilon _L\) yeyona ngxaki iphezulu enokufumaneka kwi-SMA wire.
I-phase dynamics equation ihambelana nomsebenzi we-cosine owaphuhliswa nguLiang29 waza kamva wamkelwe nguBrinson30 endaweni yomsebenzi we-exponential owaphakanyiswa nguTanaka28. Imodeli yenguqu yesigaba lulwandiso lwemodeli ecetywayo ngu-Elakhinia kunye no-Ahmadian34 kwaye yaguqulwa ngokusekelwe kwiimeko zenguqu yesigaba ezinikwe nguLiang29 kunye noBrinson30. Iimeko ezisetyenzisiweyo kule modeli yenguqu yesigaba zisebenza phantsi kwemithwalo enzima ye-thermomechanical. Ngawo onke amaxesha, ixabiso leqhekeza levolumu ye-martensite libalwa xa kuqhutywa imodeli ye-constitutive equation.
I-equation yokuguqulwa kwakhona elawulayo, ebonakaliswa kukuguqulwa kwe-martensite ibe yi-austenite phantsi kweemeko zokufudumeza, yile ilandelayo:
apho \(\xi\) liqhezu levolumu ye-martensite, \(\xi _M\) liqhezu levolumu ye-martensite efunyenwe ngaphambi kokufudumeza, \(\displaystyle a_A = \pi /(A_f – A_s)\), \ ( \displaystyle b_A = -a_A/C_A\) kunye \(C_A\) – iiparameter zokusondela kwe-curve, ubushushu bentambo ye-T – SMA, \(A_s\) kunye \(A_f\) – ukuqala nokuphela kwesigaba se-austenite, ngokulandelelana, ubushushu.
I-equation yokulawula utshintsho oluthe ngqo, emelwe lutshintsho lwesigaba se-austenite ukuya kwi-martensite phantsi kweemeko zokupholisa, yile:
apho \(\xi _A\) liqhezu levolumu ye-martensite efunyenwe ngaphambi kokuba iphole, \(\displaystyle a_M = \pi /(M_s – M_f)\), \(\displaystyle b_M = -a_M/C_M\) kunye \ (C_M \) – iiparameter zokulinganisa ijika, ubushushu bentambo ye-T – SMA, \(M_s\) kunye \(M_f\) – ubushushu bokuqala nobokugqibela be-martensite, ngokulandelelana.
Emva kokuba ii-equations (3) kunye ne-(4) zahlulwe, ii-equations zenguqu ezichaseneyo nezithe ngqo zenziwa lula kule ndlela ilandelayo:
Ngexesha lokuguqulwa kwe-forward ne-backward \(\eta _{\sigma}\) kunye ne-\(\eta _{T}\) zithatha amaxabiso ahlukeneyo. Ii-equation ezisisiseko ezinxulumene ne-\(\eta _{\sigma}\) kunye ne-\(\eta _{T}\) zifunyenwe kwaye zaxoxwa ngokweenkcukacha kwicandelo elongezelelweyo.
Amandla obushushu afunekayo ukunyusa ubushushu bentambo ye-SMA avela kwisiphumo sokufudumeza seJoule. Amandla obushushu afunxwa okanye akhutshwa yintambo ye-SMA amelwa bubushushu obufihlakeleyo bokuguquka. Ukulahleka kobushushu kwintambo ye-SMA kungenxa yokunyanzeliswa kwe-convection, kwaye ngenxa yesiphumo esincinci semitha, i-equation yebhalansi yamandla obushushu yile ilandelayo:
Apho \(m_{wire}\) bubunzima obupheleleyo bentambo ye-SMA, \(c_{p}\) bubukhulu bobushushu obuthile be-SMA, \(V_{in}\) yi-voltage esetyenziswa kwintambo, \(R_{ohm} \ ) – ukumelana okuxhomekeke kwisigaba SMA, echazwa njenge; \(R_{ohm} = (l/A_{cross})[\xi r_M + (1-\xi )r_A]\ ) apho \(r_M\ ) kunye \(r_A\) zii-resistivity zesigaba se-SMA kwi-martensite kunye ne-austenite, ngokwahlukeneyo, \(A_{c}\) yindawo engaphezulu yentambo ye-SMA, \(\Delta H \) yi-alloy yememori yesimo. Ubushushu obufihlakeleyo botshintsho lwentambo, u-T kunye no-\(T_{\infty}\) bubushushu bentambo ye-SMA kunye nokusingqongileyo, ngokwahlukeneyo.
Xa ucingo lwe-shape memory alloy luqhutywa, ucingo luyaxinwa, ludala amandla kwisebe ngalinye loyilo lwe-bimodal olubizwa ngokuba yi-fiber force. Amandla eefayibha kwintambo nganye yocingo lwe-SMA kunye enza amandla emisipha ukuba asebenze, njengoko kubonisiwe kwiFig. 9e. Ngenxa yokubakho kwentwasahlobo evulelekileyo, amandla emisipha iyonke ye-Nth multilayer actuator yile:
Ukufaka i-\(N = 1\) kwi-equation (7), amandla emisipha ye-prototype ye-bimodal drive yesigaba sokuqala anokufunyanwa ngolu hlobo lulandelayo:
apho u-n linani lemilenze ye-unimodal, \(F_m\) ngamandla emisipha aveliswa yi-drive, \​(F_f\) ngamandla efayibha kwi-SMA wire, \(K_x\) bukuqina kwe-bias. intwasahlobo, \(\alpha\) yi-engile yenxantathu, \(x_0\) yindlela yokuqala yentwasahlobo ye-bias yokubamba intambo ye-SMA kwindawo ebekwe ngaphambili, kwaye \(\Delta x\) yindlela yokuhamba ye-actuator.
Ukuhanjiswa okanye intshukumo iyonke yedrive (\(\Delta x\)) kuxhomekeke kwivoltage (\(\sigma\)) kunye noxinzelelo (\(\epsilon\)) kwi-SMA wire yesigaba seNth, idrive imiselwe (jonga iFig. inxalenye eyongezelelweyo yemveliso):
Ii-kinematic equations zinika ubudlelwane phakathi kokuguqulwa kwe-drive (\(\epsilon\)) kunye nokususwa okanye ukufuduka (\(\Delta x\)). Ukuguqulwa kwentambo ye-Arb njengomsebenzi wobude bokuqala bentambo ye-Arb (\(l_0\)) kunye nobude bentambo (l) nangaliphi na ixesha i-t kwisebe elinye le-unimodal yile ilandelayo:
apho \(l = \sqrt{l_0^2 +(\Delta x_1)^2 – 2 l_0 (\Delta x_1) \cos \alpha _1}\) ifunyanwa ngokusebenzisa ifomula ye-cosine kwi \(\Delta\)ABB ', njengoko kubonisiwe kuMfanekiso 8. Kwidrayivu yokuqala yesigaba (\(N = 1\)), \(\Delta x_1\) yi \(\Delta x\), kwaye \(\alpha _1\) yi \(\alpha \) njengoko kubonisiwe kuMfanekiso 8, ngokwahlula ixesha kwi-Equation (11) kunye nokufaka ixabiso lika-l endaweni yalo, izinga loxinzelelo lingabhalwa ngolu hlobo:
apho \(l_0\) bubude bokuqala bentambo ye-SMA, u-l bubude bentambo nangaliphi na ixesha u-t kwisebe elinye le-unimodal, \(\epsilon\) kukuguqulwa okuphuhliswe kwintambo ye-SMA, kwaye \(\alpha \) yi-engile yenxantathu, \(\Delta x\) yi-drive offset (njengoko kubonisiwe kuMfanekiso 8).
Zonke izakhiwo ze-n ezine-single-peak (\(n=6\) kulo mfanekiso) ziqhagamshelwe kuthotho lwe-\(V_{in}\) njenge-input voltage. Isigaba I: Umzobo we-Schematic we-SMA wire kwi-bimodal configuration phantsi kweemeko ze-zero voltage Isigaba II: Isakhiwo esilawulwayo siboniswa apho i-SMA wire icinezelwe ngenxa yokuguqulwa okuchaseneyo, njengoko kuboniswe ngumgca obomvu.
Njengobungqina bengcamango, i-SMA-based bimodal drive yaphuhliswa ukuze kuvavanywe ukufunyanwa okulinganisiweyo kwee-equations ezingaphantsi kunye neziphumo zovavanyo. Imodeli yeCAD ye-bimodal linear actuator iboniswe kumzobo 9a. Kwelinye icala, kumzobo 9c ibonisa uyilo olutsha olucetywayo lonxibelelwano lwe-rotary prismatic kusetyenziswa i-actuator esekwe kwi-SMA ene-plane ezimbini enesakhiwo se-bimodal. Iinxalenye ze-drive zenziwe kusetyenziswa ukwenziwa kwe-additive kwiprinta ye-Ultimaker 3 Extended 3D. Izinto ezisetyenziselwa ukuprinta kwe-3D kwezinto yi-polycarbonate efanelekileyo kwizixhobo ezimelana nobushushu njengoko inamandla, ihlala ixesha elide kwaye inobushushu obuphezulu be-transition yeglasi (110-113 \(^{\circ }\) C). Ukongeza, i-Dynalloy, Inc. Flexinol shape memory alloy wire yasetyenziswa kwizilingo, kwaye iipropati zezinto ezihambelana ne-Flexinol wire zasetyenziswa kwi-simulations. Iintambo ezininzi ze-SMA zicwangciswe njengeefayibha ezikhoyo kulungiselelo lwezihlunu olune-bimodal ukuze kufumaneke amandla aphezulu aveliswa zii-actuators ezine-multilayer, njengoko kubonisiwe kwiFig. 9b, d.
Njengoko kubonisiwe kuMfanekiso 9a, i-acute angle eyenziwe yi-movable arm SMA wire ibizwa ngokuba yi-angle (\(\alpha\)). Ngee-terminal clamps ezinamathele kwii-clamps zasekhohlo nasekunene, i-SMA wire ibanjwe kwi-bimodal angle efunekayo. Isixhobo se-bias spring esibanjwe kwi-spring connector senzelwe ukulungisa amaqela ahlukeneyo e-bias spring extension ngokwenani (n) lee-SMA fibers. Ukongeza, indawo yeendawo ezihambayo yenzelwe ukuba i-SMA wire ivezwe kwindawo yangaphandle ukuze ipholise nge-convection. Iipleyiti eziphezulu nezisezantsi ze-detachable assembly zinceda ukugcina i-SMA wire ipholile ngee-extruded cutouts ezenzelwe ukunciphisa ubunzima. Ukongeza, zombini iziphelo ze-CMA wire zinamathele kwi-terminals zasekhohlo nasekunene, ngokulandelelana, ngokusebenzisa i-crimp. I-plunger iqhotyoshelwe kwelinye icala le-movable assembly ukugcina indawo phakathi kweepleyiti eziphezulu nezisezantsi. I-plunger ikwasetyenziselwa ukusebenzisa amandla okuvimba kwi-sensor nge-contact ukulinganisa amandla okuvimba xa i-SMA wire iyasebenza.
Isakhiwo semisipha ye-bimodal i-SMA siqhagamshelwe ngombane ngochungechunge kwaye sisebenza nge-input pulse voltage. Ngexesha lomjikelo we-voltage pulse, xa kusetyenziswa i-voltage kwaye i-SMA wire ishushu ngaphezu kobushushu bokuqala be-austenite, ubude be-wire kwi-strand nganye buyafinyezwa. Oku kurhoxiswa kuvula i-subassembly yengalo eshukumayo. Xa i-voltage yayibekwe kwi-zero kumjikelo ofanayo, i-SMA wire eshushu yayipholiswa ngaphantsi kobushushu bomphezulu we-martensite, ngaloo ndlela ibuyela kwindawo yayo yokuqala. Phantsi kweemeko zoxinzelelo lwe-zero, i-SMA wire iqale yolulwe nge-bias spring ukuze ifikelele kwimeko ye-martensitic eqhekekileyo. I-screw, apho i-SMA wire idlula khona, ihamba ngenxa yoxinzelelo oludalwe kukusebenzisa i-voltage pulse kwi-SMA wire (i-SPA ifikelela kwi-austenite phase), ekhokelela ekusebenzeni kwe-movable lever. Xa i-SMA wire irhoxiswa, i-bias spring idala amandla achaseneyo ngokusolula i-spring ngakumbi. Xa uxinzelelo kwi-voltage ye-impulse luba zero, intambo ye-SMA iyanwebeka kwaye itshintshe imo yayo ngenxa yokupholisa ngenkani i-convection, ifikelela kwisigaba se-martensitic esiphindwe kabini.
Inkqubo ye-actuator esekwe kwi-SMA ecetywayo inesimo se-bimodal apho iingcingo ze-SMA zibekwe khona. (a) ibonisa imodeli ye-CAD yeprototype, ekhankanya ezinye zezixhobo kunye neentsingiselo zazo zeprototype, (b, d) imele iprototype yovavanyo ephuhlisiweyo35. Ngelixa (b) ibonisa umbono ophezulu weprototype kunye noqhagamshelo lombane kunye nezipringi ze-bias kunye neegauge zoxinzelelo ezisetyenzisiweyo, (d) ibonisa umbono wombono wokuseta. (e) Umzobo wenkqubo ye-actuation ethe ngqo eneengcingo ze-SMA ezibekwe kabini nangaliphi na ixesha t, ebonisa indlela kunye nendlela yefayibha kunye namandla emisipha. (c) Uqhagamshelo lwe-prismatic olujikelezayo lwe-2-DOF lucetyisiwe lokusebenzisa i-actuator esekwe kwi-SMA yeplani ezimbini. Njengoko kubonisiwe, ikhonkco lidlulisela intshukumo ethe ngqo ukusuka kwi-drive esezantsi ukuya kwingalo ephezulu, okwenza uqhagamshelo olujikelezayo. Kwelinye icala, intshukumo yesibini seeprism iyafana nentshukumo ye-multilayer first stage drive.
Kwenziwe uphando lovavanyo kwiprototype eboniswe kwiFig. 9b ukuvavanya ukusebenza kwe-bimodal drive esekelwe kwi-SMA. Njengoko kubonisiwe kwiFig. 10a, ukuseta kovavanyo kwakuquka umbane we-DC ocwangcisiweyo ukubonelela nge-input voltage kwiintambo ze-SMA. Njengoko kubonisiwe kwiFig. 10b, i-piezoelectric strain gauge (PACEline CFT/5kN) yasetyenziswa ukulinganisa amandla okuvimba kusetyenziswa i-Graphtec GL-2000 data logger. Idatha irekhodwa yi-host ukuze ifundwe ngakumbi. Ii-Strain gauges kunye nee-charge amplifiers zifuna umbane oqhubekayo ukuvelisa isignali ye-voltage. Izibonakaliso ezihambelanayo ziguqulwa zibe yimveliso yamandla ngokwemvakalelo ye-piezoelectric force sensor kunye nezinye iiparameter njengoko kuchaziwe kwiTheyibhile 2. Xa kusetyenziswa i-voltage pulse, ubushushu be-SMA wire buyanda, nto leyo ebangela ukuba i-actuator ivelise amandla. Iziphumo zovavanyo zokuphuma kwamandla emisipha yi-input voltage pulse ye-7 V ziboniswe kwiFig. 2a.
(a) Inkqubo ye-actuator esekwe kwi-SMA yamiselwa kolu vavanyo ukulinganisa amandla aveliswa yi-actuator. Iseli yomthwalo ilinganisa amandla okuvimba kwaye iqhutywa ngumbane we-24 V DC. Ukuhla kwe-voltage ye-7 V kwasetyenziswa kubude bonke bentambo kusetyenziswa umbane we-GW Instek ocwangcisiweyo we-DC. Intambo ye-SMA iyancipha ngenxa yobushushu, kwaye ingalo eshukumayo iqhagamshelana neseli yomthwalo kwaye isebenzisa amandla okuvimba. Iseli yomthwalo iqhagamshelwe kwi-data logger ye-GL-2000 kwaye idatha igcinwa kwi-host ukuze iqhubeke nokucutshungulwa. (b) Umzobo obonisa uthotho lwezinto zeseti yovavanyo lokulinganisa amandla emisipha.
Ii-alloys zememori yemilo ziyavuselelwa ngamandla obushushu, ngoko ke ubushushu buba yiparameter ebalulekileyo yokufunda isiganeko sememori yemilo. Ngokwenzululwazi, njengoko kubonisiwe kwiFig. 11a, ukulinganisa ubushushu kunye nokulinganisa ubushushu kwenziwe kwi-actuator ye-SMA-based divalerate. Umthombo we-DC ocwangcisiweyo usebenzise i-input voltage kwiintambo ze-SMA kwisetingi yovavanyo, njengoko kubonisiwe kwiFig. 11b. Utshintsho lobushushu lwentambo ye-SMA lulinganiswe ngexesha langempela kusetyenziswa ikhamera ye-LWIR enesisombululo esiphezulu (FLIR A655sc). Umsingathi usebenzisa isoftware ye-ResearchIR ukurekhoda idatha ukuze iqhubeke nokucutshungulwa. Xa kusetyenziswa i-voltage pulse, ubushushu bentambo ye-SMA buyanda, nto leyo ebangela ukuba intambo ye-SMA inciphe. Kwifig. Umfanekiso 2b ubonisa iziphumo zovavanyo lobushushu bentambo ye-SMA xa kuthelekiswa nexesha le-input voltage pulse ye-7V.