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A na-eji ihe owuwu Sanwichi eme ihe n'ọtụtụ ụlọ ọrụ n'ihi akụrụngwa akụrụngwa ha dị elu. The interlayer nke ihe owuwu ndị a bụ ihe dị ezigbo mkpa na-achịkwa na melite ha n'ibu Njirimara n'okpuru dị iche iche loading ọnọdụ. Akụkụ concave lattice bụ ndị pụtara ìhè maka ojiji dị ka interlayers na ụdị Sanwichi dị otú ahụ maka ọtụtụ ihe kpatara ya, ya bụ imezi ngbanwe ha (dịka ọmụmaatụ, oke nke Poisson na ụkpụrụ nhịahụ ike) na ductility (dịka ọmụmaatụ, elu elasticity) maka ịdị mfe. A na-enweta ikike nha ike na ịdị arọ site n'ịgbanwe naanị ihe geometric nke mejupụtara cell unit. N'ebe a, anyị na-enyocha nzaghachi mgbanwe nke 3-layer concave core sanwichi panel site na iji nyocha (ntụgharị zigzag tiori), mgbakọ (ya bụ, mmewere njedebe) na ule nnwale. Anyị tụlekwara mmetụta dị iche iche geometric parameters nke concave lattice Ọdịdị (dịka akụkụ, ọkpụrụkpụ, unit cell ogologo na ịdị elu ruru) na mkpokọta n'ibu omume nke Sanwichi Ọdịdị. Anyị achọpụtala na ihe ndị bụ isi nwere omume auxetic (ya bụ, ihe na-adịghị mma Poisson's ratio) na-egosipụta ike mgbanwe dị elu yana nrụrụ aka dị ntakịrị site n'ibe ụgbọ elu ma e jiri ya tụnyere gratings. Ihe nchoputa anyi nwere ike imeghe uzo maka mmepe nke ihe owuwu otutu ihe eji eme ihe nke nwere isi ihe eji eme ihe maka ikuku ikuku na ngwa biomedical.
N'ihi ike ha dị elu na ịdị arọ dị ala, a na-eji ihe owuwu Sanwichi eme ihe n'ọtụtụ ụlọ ọrụ, gụnyere nhazi akụrụngwa na akụrụngwa egwuregwu, mmiri, ikuku ikuku, na injinia biomedical. Ihe owuwu concave lattice bụ otu onye nwere ike na-ewere dị ka isi n'ígwé dị n'ụdị ihe mejupụtara n'ihi ikike mmịnye ike ha dị elu yana ikike ịdị arọ dị elu1,2,3. N'oge gara aga, agbala mbọ dị ukwuu iji chepụta ihe owuwu Sanwichi dị fechaa nwere lattice concave iji meziwanye akụrụngwa akụrụngwa. Ihe atụ nke atụmatụ ndị dị otú ahụ gụnyere ibu nrụgide dị elu n'ime ụgbọ mmiri na ihe na-awụ akpata oyi n'ahụ n'ime ụgbọ ala4,5. Ihe kpatara ihe owuwu concave lattice ji ewu ewu nke ukwuu, pụrụ iche ma dabara adaba maka iwu ụlọ Sanwichi bụ ikike ya ịmegharị akụrụngwa elastomechanical ya n'onwe ya (dịka isi ike na ntụnyere Poisson). Otu ihe na-adọrọ mmasị dị otú ahụ bụ omume auxetic (ma ọ bụ ihe ọjọọ Poisson's ratio), nke na-ezo aka na mgbasawanye mpụta nke ihe owuwu lattice mgbe a na-agbatị ogologo oge. Omume a na-adịghị ahụkebe metụtara nhazi microstructural nke mkpụrụ ndụ elementrị mejupụtara ya7,8,9.
Kemgbe nyocha mbụ ọdọ mmiri mere n'imepụta ụfụfụ auxetic, agbala mbọ dị ukwuu iji wulite ihe owuwu porous nwere oke Poisson na-adịghị mma10,11. Atụpụtala ọtụtụ geometries iji nweta ebumnobi a, dị ka chiral, ọkara siri ike, na sel nkeji na-agbanwe agbanwe,12 niile na-egosipụta omume auxetic. Ọbịbịa nke teknụzụ mgbakwunye (AM, nke a makwaara dị ka mbipụta 3D) emewokwa ka mmejuputa usoro auxetic 2D ma ọ bụ 3D13.
Omume auxetic na-enye ihe eji arụ ọrụ pụrụ iche. Dịka ọmụmaatụ, ọdọ mmiri na Elms14 egosila na ụfụfụ auxetic nwere ike mkpụrụ dị elu, ikike nnabata ike dị elu, yana isi ike dị ala karịa ụfụfụ. N'ihe gbasara akụrụngwa na-arụ ọrụ ike nke ụfụfụ auxetic, ha na-egosi nguzogide dị elu n'okpuru ibu na-agbaji ike na elongation dị elu n'okpuru esemokwu dị ọcha15. Tụkwasị na nke ahụ, iji eriri auxetic eme ihe dị ka ihe na-agba ume na ihe ndị mejupụtara ga-emeziwanye ihe arụ ọrụ ha16 na iguzogide mmebi nke eriri eriri na-agbatị17.
Nnyocha egosiwokwa na iji ihe owuwu concave auxetic dị ka isi n'ụdị ihe mejupụtara gbagọrọ agbagọ nwere ike imeziwanye arụmọrụ ha na-anọghị n'ụgbọ elu, gụnyere ike na-agbanwe agbanwe na ike18. N'iji ihe nlere anya, a hụkwara na isi auxetic nwere ike ime ka ike gbajiri agbaji nke panels composite19. Ngwakọta nke nwere eriri auxetic na-egbochikwa ịgbasa mgbape ma e jiri ya tụnyere fibers ochie20.
Zhang et al.21 chepụtara omume nkukota siri ike nke nhazi cell lọta. Ha chọpụtara na enwere ike imeziwanye voltaji na nnabata ike site na ịbawanye akụkụ nke cell auxetic unit, na-ebute grating nwere oke Poisson na-adịghị mma. Ha tụkwara aro na enwere ike iji akụkụ Sanwichi auxetic dị otú ahụ dị ka ihe nchebe megide ibu mmetụta dị elu. Imbalzano et al.22 kwukwara na auxetic composite Ibé akwụkwọ nwere ike igbasa ọzọ ume (ie ugboro abụọ) site plastic deformation na ike ibelata top ọsọ na agbara n'akụkụ site 70% tụnyere otu ply Ibé akwụkwọ.
N'ime afọ ndị na-adịbeghị anya, a na-akwụ ụgwọ nlebara anya nke ukwuu na nyocha ọnụọgụ na nnwale nke ihe owuwu Sanwichi nwere ihe mkpuchi auxetic. Ọmụmụ ihe ndị a na-akọwapụta ụzọ isi meziwanye ihe arụrụ arụ nke ụlọ Sanwichi ndị a. Dịka ọmụmaatụ, ịtụle oyi akwa auxetic zuru oke dị ka isi nke panel Sanwichi nwere ike ịkpata modul na-eto eto dị elu karịa oyi akwa23 siri ike. Na mgbakwunye, enwere ike imeziwanye omume ịgbagọ nke laminated beams 24 ma ọ bụ auxetic core tubes 25 site na njikarịcha algọridim. Enwere ọmụmụ ihe ndị ọzọ gbasara nnwale igwe nke ihe owuwu sanwichi nwere ike ịgbasa n'okpuru ibu dị mgbagwoju anya. Dịka ọmụmaatụ, nnwale mkpakọ nke ihe mejupụtara ihe mejupụtara ya na mkpokọta auxetic, ogwe Sanwichi dị n'okpuru ibu mgbawa27, ịgbagọ tests28 na nnwale mmetụta dị ala29, yana nyocha nke na-ehulata na-abụghị linear nke akụkụ Sanwichi nwere arụ ọrụ dị iche iche auxetic aggregates30.
N'ihi na ịme anwansị kọmputa na nyocha nnwale nke ụdị aghụghọ ndị dị otú ahụ na-ewekarị oge ma na-efu ọnụ, ọ dị mkpa ịmepụta usoro usoro iwu nke nwere ike ịnye ozi nke ọma na nke ọma nke dị mkpa iji chepụta ihe owuwu multilayer auxetic isi n'okpuru ọnọdụ ntinye aka ike. oge ezi uche dị na ya. Agbanyeghị, ụzọ nyocha ọgbara ọhụrụ nwere oke oke. Karịsịa, echiche ndị a ezughị oke iji buru amụma omume nke ihe ndị nwere nnukwu ihe mejupụtara yana nyocha ihe mejupụtara nke ọtụtụ ihe nwere ihe ngbanwe dị iche iche.
Ebe ọ bụ na ụdị nyocha ndị a dabere na ibu etinyere na ọnọdụ oke, ebe a anyị ga-elekwasị anya na omume mgbanwe nke akụkụ Sanwichi auxetic. Ntụle otu oyi akwa nke a na-eji maka nyocha ndị dị otú ahụ enweghị ike ịkọ n'ụzọ ziri ezi nhụsianya shear na axial na laminates na-adịghị mma nke ukwuu na ngwakọta Sanwichi na-agafeghị oke. Ọzọkwa, na ụfọdụ echiche (dịka ọmụmaatụ, na tiori Layered), ọnụ ọgụgụ nke mgbanwe kinematic (dịka ọmụmaatụ, mbugharị, ọsọ ọsọ, wdg) dabere na ọnụ ọgụgụ nke ọkwa. Nke a pụtara na enwere ike ịkọwa mpaghara mmegharị nke oyi akwa ọ bụla n'onwe ya, ebe ọ na-eju ụfọdụ ihe mgbochi anụ ahụ. Ya mere, nke a na-eduga n'ịtụle ọnụ ọgụgụ dị ukwuu nke mgbanwe dị na ihe nlereanya ahụ, nke na-eme ka usoro a dị oke ọnụ. Iji merie mmachi ndị a, anyị na-atụ aro ka usoro dabere na zigzag tiori, otu obere subclass nke tiori multilevel. Ozizi a na-enye ọga n'ihu nke nrụgide ịkwa akwa n'ogologo nke laminate ahụ, na-ewere usoro zigzag nke nchụpụ n'ime ụgbọ elu. Ya mere, ozizi zigzag na-enye otu ọnụ ọgụgụ nke mgbanwe kinematic n'agbanyeghị ọnụ ọgụgụ nke ọkwa dị na laminate.
Iji gosi ike nke usoro anyị n'ịkọ omume nke ogwe osisi Sanwichi nwere cores concave n'okpuru ibu na-ehulata, anyị jiri nsonaazụ anyị tụnyere echiche oge gboo (ya bụ, ụzọ anyị si na ụdị mgbakọ na mwepụ (ya bụ ihe nwere njedebe) na data nnwale (ya bụ nchikota isi atọ) 3D e biri ebi Sanwichi panel) .N'ihi nke a, anyị na-ebu ụzọ nweta mmekọrịta nchụpụ dabeere na zigzag tiori, wee nweta ihe mejupụtara equations site na iji ụkpụrụ Hamilton ma dozie ha site na iji usoro Galerkin. Nsonaazụ nwetara bụ ngwá ọrụ dị ike maka imewe kwekọrọ ekwekọ. akụkụ geometric nke akụkụ Sanwichi nwere ihe nrụnye auxetic, na-eme ka ịchọọ ihe owuwu nwere akụrụngwa akụrụngwa ka mma.
Tụlee otu panel Sanwichi nke okpukpu atọ (Fig 1). Akụkụ imewe geometric: elu oyi akwa \({h}_{t}\), oyi akwa etiti \({h}_{c}\) na oyi akwa ala \({h}_{ b}\) ọkpụrụkpụ. Anyị na-eche na isi ihe nhazi ahụ nwere nhazi lattice nwere oghere. Ihe owuwu ahụ nwere mkpụrụ ndụ elementrị edobere n'akụkụ ibe ya n'usoro iwu. Site n'ịgbanwe usoro geometric nke ihe owuwu concave, ọ ga-ekwe omume ịgbanwe ihe eji arụ ọrụ ya (ya bụ, ụkpụrụ nke oke Poisson na isi ike). Egosiri akụkụ geometrical nke cell elementrị na fig. 1 gụnyere akụkụ (θ), ogologo (h), ịdị elu (L) na kọlụm ọkpụrụkpụ (t).
Ozizi zigzag na-enye amụma ziri ezi nke nrụrụ aka na omume nhụsianya nke ihe owuwu jikọtara ọnụ nke oke oke. Ntugharị ihe owuwu na tiori zigzag nwere akụkụ abụọ. Akụkụ nke mbụ na-egosi omume nke panel Sanwichi n'ozuzu ya, ebe akụkụ nke abụọ na-eleba anya na omume dị n'etiti ọkwa iji hụ na nrụgide nrụgide na-aga n'ihu (ma ọ bụ ihe a na-akpọ ọrụ zigzag). Na mgbakwunye, ihe zigzag na-apụ n'anya n'elu elu nke laminate, ọ bụghị n'ime oyi akwa a. Ya mere, ọrụ zigzag na-eme ka o doo anya na oyi akwa ọ bụla na-enye aka na mkpokọta nrụrụ nke akụkụ obe. Ọdịiche a dị mkpa na-enye nkesa anụ ahụ nke ezi uche dị na ya nke ọrụ zigzag ma e jiri ya tụnyere ọrụ zigzag ndị ọzọ. Ụdị zigzag emezigharịrị ugbu a anaghị enye ọga n'ihu nrụgide shiee n'akụkụ oyi akwa etiti. Ya mere, enwere ike dee ubi nchụpụ nke dabere na tiori zigzag dị ka ndị a31.
na nha nha. (1), k=b, c na t na-anọchi anya ala, etiti na elu elu, n'otu n'otu. Ebe mgbagharị nke ụgbọ elu pụtara n'akụkụ axis Cartesian (x, y, z) bụ (u, v, w), na ntụgharị ntụgharị n'ime ụgbọ elu banyere (x, y) axis bụ \ ({\uptheta} _ {x}\) na \ ({\uptheta}_{y}\). \({\psi}_{x}\) na \({\psi}_{y}\) bụ ọnụọgụ nke ntụgharị zigzag, na \({\phi}_{x}^{k}\ aka ekpe z \right)\) na \({\phi}_{y}^{k} ekpe(z\right)\) bụ ọrụ zigzag.
Ngosipụta nke zigzag bụ ọrụ vector nke nzaghachi n'ezie nke efere ahụ na ibu etinyere. Ha na-enye nhazi ọkwa kwesịrị ekwesị nke ọrụ zigzag, si otú ahụ na-achịkwa onyinye zuru oke nke zigzag na nchụpụ na ụgbọ elu. Ọkpụkpụ n'ofe efere efere nwere ihe abụọ mejupụtara. Akụkụ nke mbụ bụ akụkụ nke shear, edo n'ofe oke nke laminate ahụ, akụkụ nke abụọ bụ ọrụ na-arụ ọrụ oge niile, otu n'ofe oke nke oyi akwa nke ọ bụla. Dị ka ọrụ ndị a na-arụ ọrụ oge niile si dị, ọrụ zigzag nke oyi akwa ọ bụla nwere ike dee dị ka:
na nha nha. (2), \({c}_{11}^{k}\) na \({c}_{22}^{k}\) bụ ihe na-agbanwe agbanwe nke oyi akwa ọ bụla, na h bụ ngụkọta ọkpụrụkpụ nke oyi akwa ọ bụla. diski ahụ. Na mgbakwunye, \({G}_{x}\) na \({G}_{y}\) bụ ọnụọgụ ngụsị ike nke shear siri ike, nke akọpụtara dị ka 31:
Ọrụ njupụta zigzag abụọ (Nha nhata (3)) na mgbanwe kinematic ise fọdụrụnụ (Nha nhata (2)) nke usoro izizi nrụrụ nke mbụ bụ usoro nke kinematics asaa jikọtara ya na mgbanwe mgbanwe nke efere zigzag a gbanwere. N'iburu n'uche ịdabere n'ahịrị nke nrụrụ ahụ ma na-eburu n'uche echiche zigzag, enwere ike nweta mpaghara nrụrụ na sistemụ nhazi Cartesian dị ka:
ebe \({\varepsilon}_{yy}\) na \({\varepsilon}_{xx}\) bụ ndakpọ nkịtị, na \({\gamma}_{yz},{\gamma}_{xz} \ ) na \({\gamma}_{xy}\) bụ nrụrụ nke shear.
N'iji iwu Hooke na-echebara echiche zigzag echiche, enwere ike nweta mmekọrịta dị n'etiti nrụgide na nsogbu nke efere orthotropic nke nwere nhazi concave lattice site na nhazi (1). (5)32 ebe \({c}_{ij}\) bụ ihe na-agbanwe agbanwe nke matriks nrụgide nrụgide.
ebe a na-egbutu \({G}_{ij}^{k}\), \({E}_{ij}^{k}\) na \({v}_{ij}^{k}\) ike bụ modul n'ụzọ dị iche iche, modul nke Young na Poisson's ratio. Ọnụọgụ ndị a hà nhata n'akụkụ niile maka oyi akwa isotopic. Na mgbakwunye, maka nuclei nke lattice na-alọghachi, dị ka egosiri na Fig. 1, enwere ike idegharị ihe ndị a dị ka 33.
Ngwa nke ụkpụrụ Hamilton na nha nha nke ngagharị nke efere multilayer nwere concave lattice core na-enye usoro nha anya maka nhazi ahụ. Enwere ike dee ụkpụrụ Hamilton dịka:
N'ime ha, δ na-anọchite anya onye na-arụ ọrụ dị iche iche, U na-anọchi anya ike ike dị ike, na W na-anọchite anya ọrụ nke ike mpụga na-arụ. A na-enweta mkpokọta ike nsogbu site na iji nha anya. (9), ebe A bụ mpaghara ụgbọ elu etiti.
N'ịtụle ngwa ngwa nke ibu (p) na ntụziaka z, ọrụ nke ike mpụga nwere ike nweta site na usoro a:
Dochie nha nha nha (4) na (5) (9) ma dochie nha nha. (9) na (10) (8) na ijikọta n'elu ọkpụrụkpụ efere, akara: (8) nwere ike idegharị dịka:
Ndekọ aha \(\phi\) na-anọchi anya ọrụ zigzag, \({N}_{ij}\) na \({Q}_{iz}\) bụ ike na-abanye na n'ime ụgbọelu, \({M}) _{ij }\) na-anọchi anya oge na-ehulata, na usoro ngụkọ bụ nke a:
Itinye ntinye aka site na akụkụ na nha anya. N'ịgbanwe n'ime usoro (12) na ịgbakọ ọnụọgụ nke mgbanwe, enwere ike nweta nhazi nhazi nke panel Sanwichi n'ụdị usoro (12). (13).
A na-edozi nha nha njikwa dị iche iche maka efere oyi akwa atọ akwadoro n'efu site na usoro Galerkin. N'okpuru echiche nke ọnọdụ quasi-static, ọrụ amaghị ama ka a na-ewere dị ka nha anya: (14).
\({u}_{m,n}\), \({v}_{m,n}\), \({w}_{m,n}\),\({{\uptheta}_ {\mathrm {x}}}_{\mathrm {m} \text{,n}}\),\({{\uptheta }_{\mathrm {y}}}_{\mathrm {m} \text {,n}}\), \({{\uppsi}_{\mathrm{x}}}_{\mathrm{m}\text{,n}}\) na \({{\uppsi}_{ \mathrm{y}}}_{\mathrm{m}\text{,n}}\) bụ ihe a na-amaghị ama nke enwere ike nweta site na ibelata njehie ahụ. \(\overline{\overline{u}} \ekpe({x{\text{,y}}} \right)\), \(\overline{\overline{v}} \ekpe({x{\text) {,y}}} \n'aka nri)\), \(\overline{\overline{w}} \ekpe( {x{\text{,y}}} \right)\), \(\overline{\overline {{\uptheta}_{x}}} \ ekpe( {x{\text{,y}}} \right)\), \(\overline{\overline{{\uptheta}_{y} }}} \n'aka ekpe( {x{\text{,y}}} \n'aka nri)\), \(\overline{\overline{{\psi_{x}}}} \ ekpe( {x{\text{, y}}} \right)\) na \(\overline {\overline {{ \psi_{y} }}} \ ekpe( {x{\text{,y}}} \right)\) bụ ọrụ ule, nke ga-egbo oke opekempe dị mkpa. Maka naanị ọnọdụ oke akwadoro, enwere ike ịgbakọ ọrụ nnwale ahụ dịka:
Dochie nha nha na-enye nha nhata algebra. (14) na nha nha na-achị achị, nke nwere ike iduga inweta ọnụọgụgụ amaghi ama na nha anya (14). (14).
Anyị na-eji ihe nlegharị anya nke mmecha (FEM) iji kọmpụta na-eme ka ehulata panel Sanwichi a na-akwadoghị nke ọma nwere usoro lattice concave dị ka isi. Emere nyocha ahụ na koodu mmecha mmecha azụmahịa (dịka ọmụmaatụ, ụdị Abaqus 6.12.1). A na-eji 3D hexahedral solid element (C3D8R) na ntinye dị mfe mee ihe iji ṅomie elu na ala ala, na linear tetrahedral element (C3D4) na-eji ihe nlereanya nke etiti (concave) lattice nhazi. Anyị mere nyocha nhịahụ nhịahụ iji nwalee njikọ nke ntupu wee kwubie na nsonaazụ mbugharị ahụ gbakọtara na nha njirimara kacha nta n'etiti ọkwa atọ ahụ. A na-ebufe efere Sanwichi site na iji ọrụ ibu sinusoidal, na-eburu n'uche ọnọdụ ókèala na-akwado kpamkpam na nsọtụ anọ. A na-ahụta omume igwe na-agbanwe ahịrị ahịrị dị ka ihe nlereanya nke ekenyere n'ígwé niile. Enweghị kọntaktị a kapịrị ọnụ n'etiti akwa akwa, ha jikọtara ọnụ.
Anyị na-eji usoro obibi akwụkwọ 3D mepụta ụdị prototype anyị (ya bụ, akụkụ atọ a na-ebipụta auxetic core sanwichi) yana nhazi nnwale dabara adaba iji tinye ọnọdụ mgbagha yiri (ibu p n'akụkụ z-direction) na ọnọdụ oke (ntụgharị naanị akwadoro). chere na usoro nyocha anyị (Fig 1).
Ogwe Sanwichi a na-ebipụta na ngwa nbipute 3D nwere skins abụọ (nke dị elu na nke ala) na isi lattice concave, nke egosiri akụkụ ya na Tebụl 1, wee rụpụta ya na ngwa nbipute Ultimaker 3 3D (Italy) site na iji usoro nkwụnye ego (Italy). FDM). a na-eji teknụzụ eme ihe na usoro ya. Anyị 3D ebipụtara isi efere na isi auxetic lattice Ọdịdị ọnụ, na-ebipụta n'elu oyi akwa iche iche. Nke a na-enyere aka izere nsogbu ọ bụla n'oge usoro iwepụ nkwado ma ọ bụrụ na a ga-ebipụta ihe niile n'usoro n'otu oge. Mgbe mbipụta 3D gasịrị, a na-ejikọta akụkụ abụọ dị iche iche site na iji superglue. Anyị ji polylactic acid (PLA) bipụta ihe ndị a na njupụta njupụta kachasị elu (ya bụ 100%) iji gbochie ntụpọ obibi akwụkwọ mpaghara ọ bụla.
Usoro njigide omenala na-eṅomi otu ọnọdụ ókèala nkwado dị mfe anabatara n'ụdị nyocha anyị. Nke a pụtara na usoro njide ahụ na-egbochi bọọdụ ịgagharị n'akụkụ akụkụ ya na ntụzịaka x na y, na-enye ohere ka akụkụ ndị a na-atụgharị kpamkpam gburugburu axes x na y. A na-eme nke a site n'ịtụle fillets na radius r = h / 2 na nsọtụ anọ nke usoro gripping (Fig 2). Usoro nkedo a na-ahụkwa na a na-ebufe ibu nke etinyere n'ụzọ zuru ezu site na igwe nyocha na panel ma kwekọọ na etiti etiti panel (fig 2). Anyị jiri teknụzụ mbipụta 3D ọtụtụ jet (ObjetJ735 Connex3, Stratasys® Ltd., USA) na resins azụmahịa siri ike (dị ka usoro Vero) iji bipụta sistemụ njide.
Eserese atụmatụ nke sistemu gripping omenala 3D na mgbakọ ya nwere panel sanwichi ebipụtara 3D nwere isi auxetic.
Anyị na-eme ule mkpakọ quasi-static nke ngagharị na-achịkwa site na iji bench ule igwe (Lloyd LR, load cell = 100 N) ma na-anakọta ndị agha igwe na mbugharị n'ogo nlele nke 20 Hz.
Akụkụ a na-egosi ọmụmụ ọnụọgụgụ nke usoro Sanwichi a chọrọ. Anyị na-eche na elu na ala n'ígwé na-mere nke carbon epoxy resin, na lattice Ọdịdị nke concave isi bụ nke polima. Egosiputa ihe eji arụ ọrụ nke ihe eji eme ihe na nyocha a na Tebụl 2. Tụkwasị na nke ahụ, a na-egosipụta oke enweghị oke nke nsonaazụ mbugharị na mpaghara nrụgide na tebụl 3.
Atụnyere nchụpụ kacha kwụ ọtọ na-enweghị akụkụ kwụ ọtọ nke efere akwadoro n'otu n'otu na nsonaazụ enwetara site na ụzọ dị iche iche (Table 4). Enwere ezigbo nkwekọrịta n'etiti echiche a na-atụ aro, usoro mmewere dị oke na nkwenye nnwale.
Anyị tụlere ntughari kwụ ọtọ nke zigzag theory (RZT) gbanwetụrụ na 3D elasticity theory (Pagano), usoro izizi shear deformation theory (FSDT), na nsonaazụ FEM (lee Fig. 3). Ozizi shear nke mbụ, dabere na eserese ngosi nke nnukwu efere multilayer, dị iche na ngwọta ngbanwe. Agbanyeghị, tiori zigzag gbanwetụrụ na-ebu amụma nsonaazụ ziri ezi. Tụkwasị na nke ahụ, anyị tụlekwara nrụgide ịkwa ụda na-apụ apụ na ụgbọ elu nkịtị nke echiche dị iche iche, n'ime nke zigzag tiori nwetara nsonaazụ ziri ezi karịa FSDT (Fig 4).
Ntụle ụdị kwụ ọtọ gbakọrọ site na iji echiche dị iche iche na y = b/2.
Mgbanwe na nrụgide shear (a) na nrụgide nkịtị (b) n'ofe oke nke panel Sanwichi, gbakọọ site na iji echiche dị iche iche.
Ọzọ, anyị nyochaa mmetụta nke geometric parameters nke unit cell na concave isi n'ozuzu n'ibu Njirimara nke Sanwichi panel. Akụkụ cell unit bụ ihe kacha mkpa geometric n'ime nhazi nke reentrant lattice structures34,35,36. Ya mere, anyị gbakọọ mmetụta nke unit cell akụkụ, nakwa dị ka ọkpụrụkpụ n'èzí isi, na ngụkọta deflection nke efere (Fig. 5). Ka ọkpụkpụ nke oyi akwa etiti na-abawanye, ngbanwe nke enweghị akụkụ na-ebelata. Ike mgbagọ nke ikwu na-abawanye maka akwa isi dị oke na mgbe \(\frac{{h}_{c}}{h}=1\) (ya bụ, mgbe enwere otu oyi akwa concave). Oghere Sanwichi nwere cell auxetic unit (ie (\theta =70^\circ\)) nwere nchụpụ ndị kacha nta (Fig 5). Nke a na-egosi na ike na-ehulata nke isi auxetic dị elu karịa nke isi auxetic a na-emekarị, mana ọ naghị arụ ọrụ nke ọma ma nwee oke Poisson dị mma.
Ntugharị kacha elu nke mkpanaka concave nwere akụkụ cell dị iche iche yana ọkpụrụkpụ nke na-apụ apụ.
Ọkpụrụkpụ nke isi nke grating auxetic na akụkụ akụkụ (ie \(\theta=70^\circ\)) na-emetụta nchụpụ kacha elu nke efere Sanwichi (ọgụgụ 6). Enwere ike ịhụ na ntụgharị kachasị elu nke efere ahụ na-abawanye na h / l na-abawanye. Tụkwasị na nke ahụ, ịba ụba nke isi auxetic na-ebelata porosity nke ihe owuwu concave, si otú ahụ na-amụba ike na-ehulata nke ihe owuwu ahụ.
Mgbanwe kachasị nke akụkụ Sanwichi kpatara site na ihe owuwu lattice nwere isi auxetic nke ọkpụrụkpụ na ogologo dị iche iche.
Ọmụmụ nke mpaghara nrụgide bụ mpaghara na-adọrọ mmasị nke enwere ike inyocha site na ịgbanwe akụkụ geometric nke otu cell iji mụọ ụdị ọdịda ọdịda (dịka ọmụmaatụ, delamination) nke ihe owuwu multilayer. Oke Poisson na-enwe mmetụta dị ukwuu n'ọhịa nke nrụgide ịkwa ụda n'èzí karịa nrụgide nkịtị (lee foto 7). Tụkwasị na nke a, mmetụta a bụ inhomogeneous na ntụziaka dị iche iche n'ihi orthotropic Njirimara nke ihe ndị a gratings. Akụkụ geometric ndị ọzọ, dị ka ọkpụrụkpụ, ịdị elu, na ogologo nke ihe owuwu concave, enwechaghị mmetụta na mpaghara nrụgide, n'ihi ya, enyochaghị ha n'ọmụmụ ihe a.
Gbanwee ihe ndị na-akpata nrụgide shear n'ígwé dị iche iche nke panel Sanwichi nwere ihe mkpuchi lattice nwere akụkụ concavity dị iche iche.
N'ebe a, a na-enyocha ike na-ehulata nke efere multilayer na-akwadoghị nke nwere concave lattice core site na iji tiori zigzag. Atụnyere usoro a na-atụ aro ya na echiche oge gboo ndị ọzọ, gụnyere tiori ngbanwe akụkụ atọ, tiori nrụrụ nke shear nke mbụ, na FEM. Anyị na-akwadokwa usoro anyị site n'ịtụle nsonaazụ anyị na nsonaazụ nnwale n'ụdị Sanwichi ebipụtara 3D. Nsonaazụ anyị na-egosi na ozizi zigzag nwere ike ịkọ nrụrụ nke akụkụ Sanwichi nke oke oke n'okpuru ibu na-ehulata. Tụkwasị na nke ahụ, a na-enyocha mmetụta nke geometric parameters nke concave lattice Ọdịdị na omume na-ehulata nke ogwe Sanwichi. Nsonaazụ na-egosi na ka ọkwa nke auxetic na-abawanye (ie, θ <90), ike na-ehulata na-abawanye. Na mgbakwunye, ịbawanye akụkụ akụkụ na ibelata ọkpụrụkpụ nke isi ga-ebelata ike ịgbagọ nke panel Sanwichi. N'ikpeazụ, a na-amụ mmetụta nke Poisson's ratio na nrụrụ n'elu ụgbọ elu, ma kwenye na oke nke Poisson nwere mmetụta kachasị ukwuu na nrụgide shiee nke na-emepụta site na ọkpụrụkpụ nke efere laminated. Usoro na nkwubi okwu ndị a na-atụ aro nwere ike imeghe ụzọ maka imepụta na njikarịcha ihe owuwu multilayer nwere concave lattice fillers n'okpuru ọnọdụ ntinye dị mgbagwoju anya dị mkpa maka imepụta ihe owuwu na-ebu ibu na mbara igwe na teknụzụ biomedical.
Ihe ndekọ data ejiri na/ma ọ bụ nyochaa n'ime ọmụmụ ihe ugbu a dị site n'aka ndị edemede dị iche iche na arịrịọ ezi uche dị na ya.
Aktai L., Johnson AF na Kreplin B. Kh. Ntugharị ọnụọgụgụ nke njirimara mbibi nke cores ebuanu. injinia. fractal. ajị anụ. 75 (9), 2616–2630 (2008).
Gibson LJ na Ashby MF Porous Solids: Ọdịdị na Njirimara (Cambridge University Press, 1999).
Oge nzipu: Ọgọst-12-2023