Kev sib cais me me yog qhov tawm ntawm kev qhuab qhia uas tau tsuas yog tsim hauv kev tsim kho xyoo tsis ntev los no. Nws tseem ceeb tshaj plaws hauv cov xwm txheej uas muaj lub cev kabmob tsis dhau ntawm qhov nthuav dav ntawm lub ntsiab (suav nrog kev nthuav dav nyob rau hauv lub zog zoo li qub thiab qaug zog thauj). Qhov kev sib tw sib xws yog siv rau kev tsom xam ntawm ntau cov qauv txheej txheem, thiab cov txheej txheem los ntawm kev nrhav kev pib thiab nthuav tawm kom tsis muaj peev xwm yog nyob hauv nws qhov kev tshawb xyuas tau. Vim nws yog ncaj qha cuam tshuam nrog cov teeb meem kev nyab xeeb ntawm cov ntaub ntawv lossis cov qauv kev sim, ob qho kev sim thiab cov tswv yim tau tsim sai thiab tau siv dav hauv engineering sai. Cov txheej txheem ntawm kev tshawb fawb mechanics yog: Pib ntawm Elastic me me tshuab sib npaug, thiab kev kuaj cov kab zauv uas tswj cov pob txha uas tswj tau yooj yim thiab cov pob zeb hauv zos uas nyob ze ntawm cov taub hau.
Cov xwm txheej tam sim no ntawm cov kev tshawb fawb txog tsev thiab txawv teb chaws
Tam sim no, kev tshawb fawb tag nrho ntawm pob txha me yog: los ntawm linear elasticity rau elastic - Yas yooj yim; Los ntawm zoo li qub bacture rau dynamic bacture; los ntawm macroscopic thiab me me me me sib cais rau macroscopic thiab cov ntawv metchopic; los ntawm kev txiav txim siab cov hau kev los ua qhov probabilistic thiab cov qauv kev ntseeg. Yog li ntawd, kom deb li deb li yooj yim mechanics nws tus kheej muaj kev txhawj xeeb, raws li cov ntsiab lus tshwj xeeb thiab cais tawm mechanics (motorcopic bypacture mechanics (bareing rau qeb ntawm hlau physics). Macroscopic Skacture mechanics tuaj yeem faib ua txoj kev me me thiab cov neeg siv hluav taws xob me me - thiab loj} Cov pob txha lov - thiab suav nrog cov me nyuam me ntsis ua kom tawg yooj yim me ntsis me ntsis kev sib cav sib ceg). Engineering tshuab me me kuj suav nrog cov khoom tseem ceeb ntawm kev tsim khoom zoo xws li qaug zog, corrosion bacture, corrosion ua kom qaug zog, corrosion rog tsis sib xws thiab nkag ua kom qaug zog ua kom tawg. Tam sim no, kev ntseeg tau cov kev tshawb nrhiav hauv cov txheej txheem kev tshawb fawb ntawm kev sib cav sib ceg, thiab txuas ntxiv ua si ntawm lub luag haujlwm tseem ceeb hauv kev xyaum ua lag luam.
1. Griffith Theory
Txhawm rau kawm txog cov kab nrib pleb sab hauv cov khoom ntawm cov khoom siv, Griffith nyob rau hauv lub zog ntawm lub khob thiab muab tau los ntawm kev sib raug zoo ntawm lub zog:
Qhov no yog lub npe nrov Griffith lov, nyob rau hauv uas G yog lub zog tso tawm ntawm cov lus qhia dawb (lub zog uas yuav tsum muaj rau cov khoom siv ib chav tsev tawg). Los ntawm cov kev sib raug zoo no, kev sib txheeb ntawm Griffithly tawg kev ntxhov siab thiab tawg tuaj yeem tau:
In the formula, a is the crack length. If G>2 s, qhov tawg yuav nthuav; Yog g<2γs, the crack will not expand; if G=2γs, it is a limit state. In addition, if the crack expands and dG/da>0, nws tuaj yeem txiav txim siab raws li tsis muaj kev nthuav dav; Yog hais tias cov nrib pleb nthuav dav thiab dg / ntaj<0, the crack stops.
2. Kev ntxhov siab siv tau k
Cov tsiaj ntawv luv ntawm txoj kev muaj kev ntxhov siab ntawm txoj kev siv tshuab yog qhov muaj kev cuam tshuam rau hauv cov kab nrib pleb Los ntawm kev kawm ntawm kev ntxhov siab teb nyob ze ntawm cov lus qhia tawg, peb paub tias kev ntxhov siab nyob ze ntawm qhov ciav hlau tawg hauv qee txoj kev, uas yog, nws muaj cov lus qhuab qhia. Yog li ntawd, kev nyuaj siab ntawm no tsis tuaj yeem siv los ntsuas nws lub zog. Tus nqi KI tuaj yeem muaj kev cuam tshuam txog lub zog ntawm txoj kev muaj kev ntxhov siab loj hauv cov chaw kaw. Nws cov nqi cuam tshuam nrog lub nra, tawg loj thiab geometry. Kev qhia ua lej ntawm Griffith burnow yog:
Qhov twg σ yog kev ntxhov siab, yog tawg ntev, thiab muaj peb daim ntawv ntawm cov kab nrib pleb Ntawm lawv, rau hom kuv tawg:
Qhov e yog kev ntxhov siab dav hlau.
Lus Cim: Kev ntxhov siab siv tau rau thaj tsam yas ntawm cov kab nrib pleb me me tshaj li qhov chaw nyob hauv K
3. J Ib qho tseem ceeb
Thov los ntawm Rice (Jrrice) xyoo 1968. Nws hais txog kev ntxhov siab thiab kev sib tsoo ntawm cov ncauj tawg vim tias loj} breading. Lub ntsiab txhais ntawm J CATIONAL yog:
Nws yog siv los kawm cov teeb meem dav hlau thiab sawv cev rau lub zog cuam tshuam kom tawg txuas ntxiv. Thawj lub sijhawm ntawm sab xis ntawm cov qauv yog lub zog ntsig txog kev sib cais, qhov chaw w yog qhov ntom ntawm lub zog (piv txwv li, lim ib ce rau ib lub zog). Nyob rau hauv rooj plaub ntawm elastic -}}, nws yog kev ntxhov siab ua haujlwm) tau txais los ntawm txhua lub ntim khoom ntawm cov hnoos qeev thaum lub sijhawm tso quav ntawm monotonic chaw thau khoom. Lub sijhawm thib ob yog lub zog quab yuam ntawm DS; DS yog lub arc keeb ntawm txoj kev γ.
J COMPORTAL muaj cov khoom hauv qab no:
J Infortal yog ywj siab ntawm txoj kev;
J COMPATIONAL tuaj yeem txiav txim siab ntawm elastic - kev nyuaj siab yas {}} strain teb ntawm cov lus qhia tawg;
J COMP MATORAL muaj kev sib raug zoo hauv qab no nrog deformation ua haujlwm zog:
Qhov twg b yog qhov tuab me me, koj yog deformation ua haujlwm ntawm cov hnoos qeev, thiab ▽ yog ib txoj haujlwm muab. Cov mis saum toj no yog lub hauv paus rau kev sim txiav txim siab ntawm j integr integral.
4. Kuj nkhaus
Nyob rau hauv bacture mechanics, ib txoj kev nkhaus uas sawv cev rau tus cwj pwm nthuav dav ntawm kev tawg hauv cov khoom (raws li qhia hauv daim duab hauv qab no). Lub ordinate yog qhov tsis kam ua kom tawg, Δ ntawm CTOD lossis kev ntxhov siab siv tau Factor K, thiab kev ntxhov siab ntau qhov txuas ntxiv ntxiv △ a. Thaum cov kab nrib pleb tsis txuas ntxiv, tus nkhaus coincides nrog cov ordinate. Thaum txuas ntxiv, △ ≠ 0, qhov nkhaus deviates los ntawm cov ordinate, thiab cov khoom muaj peev xwm taw tes yog qhov chaw nres tsheb ciav hlau. Cov hauv qab no sawv cev rau cov txheej txheem txuas ntxiv. Thaum lub sijhawm tangent ntawm ib qho kev nkhaus tuaj yeem hla dhau ntawm kab rov tav tsis zoo rau Axis sawv cev qhov ntev, nws txhais tau tias tsis muaj kev ruaj ntseg txuas ntxiv yuav tshwm sim. Thaum tsis meej tshwm sim, qhov tawg txuas ntxiv tsav tsheb thiab tawg txuas ntxiv kuj muaj qhov sib txuas ntawm kev hloov nrog qhov loj me. Cov kab nrib yuav nthuav nrawm thiab tawg tsis muaj chaw thau khoom. Txoj kev xav tsis kam yog muaj ib qho hnoos qeev, uas tuaj yeem siv los txiav txim siab qhov pib ua ntej pib tus nqi (Δ0.005, thiab muaj peev xwm siv tau los twv seb cov txheej txheem ntawm cov kab nrib pleb txuas ntxiv hauv ib qho kev sib xyaw.
5. Cov lej suav sau zauv
Nrog rau qhov tob zuj zus ntawm kev tshawb fawb mechanics, cov teeb meem uas yuav tsum tau daws tau daws tau ntau thiab ntau dua {Precision laij cov txheej txheem kub rau cov kws tshawb fawb. Vim kev tsim kho cov kev qhuab qhia no xws li kev txheeb xyuas cov txheej txheem sib txawv, thiab cov lej ua haujlwm los txhawb kev txhim kho kev sib txuas me me ntawm kev tshawb fawb mechanics.
Cov qauv zoo kawg:
Nyob rau hauv cov ntaub ntawv ntawm finite lub teeb daws, kev nplua nuj rov qab, qhov kev kwv yees ua yuam kev thiab siv hluav taws xob tsis zoo los ua kom tiav kom txog thaum muaj kev daws teeb meem zoo. Tsis tas li ntawd, cov kev sojntsuam stochastic yog qhov kev taw qhia tseem ceeb rau kev txhim kho kev sib cav thiab lub hauv paus rau kev cia siab rau kev cia siab. Ntawm lub hauv paus ntawm cov qauv zoo, cov txheej txheem muaj txiaj ntsig ntawm cov txheej txheem randameters los piav txog cov teeb meem engineering. Cov ntsiab lus tshawb fawb tseem ceeb suav nrog kev hloov pauv kev hloov pauv kev hloov pauv kev hloov pauv kev hloov pauv kev sib txawv thiab lawv cov kev daws teeb meem.
Ciam Teb Qauv:
Qhov no yog ib hom zauv tshwj xeeb rau kev daws cov teeb meem txhua yam tsim tom qab cov qauv zoo. Nws muaj pes tsawg leeg suav nrog peb ntu hauv qab no:
Cov yam ntxwv ntawm cov kev daws teeb meem yooj yim thiab nws daim ntawv thov;
Kev xaiv cov kev txiav txim siab thiab cov khoom sib khi;
Lub superposition txoj kev thiab daws thev naus laus zis.
The advantage of this method is that the Guass theorem is used to reduce the problem order, converting the three-dimensional problem into a two-dimensional problem, and converting the two-dimensional problem into a one-dimensional problem, which greatly simplifies the data preparation, makes the grid division and readjustment more convenient, and the Qhov loj me ntawm cov txheej txheem kawg algebraic zaum kawg yog qhov me dua.
Meshless txoj kev:
Kuj tseem hu ua qauv theem. Txoj kev qhia tshwj xeeb tag nrho cov kev daws teeb meem sau rau cov kev ywj pheej uas tsis tau sib txuas cov nodes rau hauv cov koog. Nws tsis tas yuav faib cov kab sib chaws, yog li kov yeej cov kev tsis xws luag ntawm cov qauv zoo uas daim phiaj yuav tsum tau hloov tshiab txuas ntxiv thaum lub sijhawm cov txheej txheem kev suav. Thaum lub sijhawm ua cov txheej txheem kev suav, thaj chaw cov kab nrib pleb tuaj yeem taug qab lub sijhawm rau kev ua kom zoo dua qub, thiab cov txheej txheem txuas ntxiv tau suav tias yog ntau txoj kev nce ntxiv. Qhov tawg ncua lub kaum sab xis nyob hauv txhua qhov kev nce qib yog txiav txim siab raws li kev ntxhov siab siv tau. Lub xam qhov tseeb tau txhim kho los ntawm kev qhia txog lub hauv paus haujlwm sab nraud ntawm cov lus qhia rov qab kho dua tshiab ntawm node.
Sau tus qauv manifold:
Cov tswv yim yooj yim ntawm hom no yog los qhia cov txiv neej sib txawv ntawm cov qauv kev tshawb xyuas, raws li cov teeb meem sib txawv ntawm cov teeb meem kev sib txawv ntawm kev ua haujlwm txuas ntxiv thiab ua haujlwm tsis sib xws.
Wavelet lej txheej txheem:
Qhov no txoj kev siv tau ntawm cov yam ntxwv zoo hauv wavelet, tsim tsa cov teeb meem kev ua haujlwm ntawm wavelet kev ua haujlwm, daws cov lus qhia txog kev ntxhov siab thiab daws cov kev ntxhov siab ntawm cov lus qhia tawg.
Cov teeb meem uas twb muaj lawm thiab tus yuam sij
Cov txheej txheem saum toj no lossis cov kev kwv yees tau tag nrho los ntawm Griffith's fracture txoj kev xav thiab yog ua raws cov qauv uas kev ntxhov siab thiab kev ntxhov siab ntawm cov taub hau tawg yog ib qho tsis kawg. Elastic mechanics piav qhia ntawm qhov kev xav ntawm lub tswv yim ntawm Inglis Mathematical Tip Tus qauv tawg yog tus lej ua ke ua qauv. Qhov kev ncua deb ntawm cov chaw sab saud thiab qis dua yog xoom, thiab lub vojvoog ntawm curvature ntawm cov lus qhia tawg kuj yog xoom. Yog li ntawd, qhov kev ntxhov siab tiv thaiv tau los ntawm kev siv tshuab me me yog qhov tsis kawg ntawm cov lus qhia tawg. Qhov tshwm sim no hu ua kev ntseeg.
Cov kev xav ntawm kev xav tau txuas ntxiv rau hnub no, tab sis cov singularity bacture mechanics muaj qhov tsis zoo nyob hauv physics, uas yog feem ntau yog ua kom pom tseeb hauv ob qho:
Ua ntej, lub voj sab saud thiab sab saud thiab lub vojvoog ntawm curvature ntawm cov taub nrib pleb pom hauv kev coj ua yog finite values thiab tsis sib npaug rau xoom;
Thib ob, hauv cov kab nrib pleb tiag, txawm tias nyob rau ntawm cov lus qhia tawg, kev ntxhov siab thiab muaj tsis muaj txiaj ntsig zoo, thiab tsis muaj li ntawd}
Nyob rau hauv txoj kev no, lub cev muaj nuj nqis raws cov lus qhia ua lej tawm thiab cov kev ntxhov siab tsis muaj lub cev muaj zog. Txhawm rau txhim kho txoj kev xav thiab tam sim no tsis yog}} kev ntsuas ntawm lub voj voos, tab sis kev sib tw ntawm cov qauv sib dhos, uas yuav tsum tau siv cov qauv ntawm daim hlau me me.
Kev tsim kho yav tom ntej
Txawm hais tias qee qhov kev nce qib tau ua nyob rau hauv elastic - Yas Txheej Txheem Mechanics, tseem tshuav ntau yam teeb meem uas yuav tsum tau kawm hauv qhov tob. Nws yog ib qho ntawm cov kev tshawb fawb tseem ceeb ntawm kev ua pob txha uas tawg tam sim no. Kev Siv Kom Zoo, rau linear cov ntaub ntawv, yuav tsum tau txhim kho; Rau cov ntaub ntawv tsis yog, nws tseem nyob rau hauv thaum ntxov ntawm kev tshawb fawb thiab yog lwm qhov kev tshawb fawb tseem ceeb ntawm kev sib tw mechanics. Nrog rau hauv - qhov tob kawm ntawm cov cuab yeej kev sim ua lej, tawg me me kev tshawb nrhiav tau ua tiav thiab yooj yim me me cov ntawv thov yuav dhau los ua ntau zuj zus.
Rau cov kev xam cov lej, cov txheej txheem kev txhim kho yav tom ntej yog cov qauv kev suav zauv, kev sib xyaw ua ke, kev sib xyaw ua ke ntawm ntau txoj kev xam, thiab cov ntaub ntawv ua haujlwm automation.
