Qhov sib txawv tseem ceeb ntawm viscoelastic thiab viscoplastic yog cov ntaub ntawv viscoelastic qhia ob qho tib si viscous thiab elastic zog thaum tab tom deformation, whereas viscoplastic cov ntaub ntawv qhia unrecoverable deformation.
Viscoelasticity thiab viscoplasticity tau piav qhia txog cov khoom ntawm cov khoom siv polymer. Ob nqe lus no piav qhia txog tus cwj pwm ntawm cov khoom siv polymer thaum lub sij hawm deformation ntawm cov polymer.
Viscoelastic yog dab tsi?
Viscoelastic cov ntaub ntawv yog cov khoom siv polymer uas qhia ob qho tib si viscous thiab elastic zog thaum lub sij hawm deformation ntawm cov khoom. Cov cuab yeej no yog hu ua viscoelasticity. Feem ntau, cov khoom viscous xws li dej tiv thaiv shear flow thiab strain linearly nrog lub sijhawm thaum peb siv kev ntxhov siab. Ntawm qhov tod tes, cov khoom elastic, thaum ncab, rov qab mus rau lawv qhov qub qub thaum qhov kev ntxhov siab raug tshem tawm. Yog li, peb tuaj yeem pom tias cov ntaub ntawv viscoelastic muaj ob qho tib si no. Tsis tas li ntawd, cov ntaub ntawv no nthuav tawm lub sijhawm nyob ntawm lub sijhawm. Feem ntau, elasticity yog qhov tshwm sim ntawm daim ntawv cog lus ncab nrog cov dav hlau crystallographic hauv cov khoom xaj, thaum viscosity yog qhov tshwm sim ntawm qhov sib txawv ntawm cov atoms lossis molecules hauv cov khoom siv amorphous.
Thaum muab piv cov khoom elastic thiab viscoelastic, cov khoom viscoelastic muaj ob qho tib si viscous thiab elastic Cheebtsam, thiab cov viscosity ntawm cov tshuaj no muab lawv tus nqi strain uas nyob ntawm lub sijhawm. Tsis tas li ntawd, cov khoom siv ntshiab elastic tsis dissipate lub zog thaum thauj khoom thiab tshem tawm, tab sis cov khoom siv viscoelastic dissipates lub zog ntawm tib lub sijhawm.
Viscoelasticity tuaj yeem txhais tau tias yog kev hloov kho molecular. Thaum peb siv kev ntxhov siab rau cov ntaub ntawv no, ib feem ntawm cov saw hlau ntev polymer hloov txoj haujlwm. Qhov kev hloov pauv no yog lub npe hu ua creep. Txawm tias tom qab qhov kev hloov kho tshiab no, cov polymer tseem nyob ruaj khov txhawm rau ua kom muaj kev ntxhov siab.
Viscoplastic yog dab tsi?
Viscoplastic cov ntaub ntawv yog cov khoom siv polymer uas qhia ob qho tib si thiab cov khoom yas thaum lub sij hawm deformation ntawm cov khoom. Cov cuab yeej no yog hu ua viscoplasticity. Nws yog tus nqi-dependent inelastic cwj pwm ntawm cov khib nyiab. Lo lus "rate-dependence" yog hais txog qhov deformation ntawm cov khoom uas nyob ntawm tus nqi ntawm cov khoom siv. Viscoplasticity yog hais txog tus cwj pwm inelastic, uas txhais tau hais tias cov khoom siv tsis tuaj yeem rov qab deformations thaum nce qib load.
Feem ntau, peb tuaj yeem ua qauv viscoplasticity hauv peb-dimension siv overstress qauv. Cov qauv no muaj qhov kev ntxhov siab tso cai kom muaj zog ntau dua li tus nqi-dependent yield nto raws li daim ntawv thov ntawm kev thauj khoom, thiab tom qab ntawd nws raug tso cai kom so rov qab mus rau qhov chaw tawm los ntawm lub sijhawm. Raws li lwm txoj hauv kev, peb tuaj yeem ntxiv qhov sib txawv ntawm qhov kev cia siab rau cov txiaj ntsig kev ntxhov siab thiab siv cov tswv yim ntawm tus nqi-ywj siab ntawm plasticity rau kev suav cov lus teb ntawm cov khoom siv.
Viscoplasticity theories yog qhov tseem ceeb hauv kev suav cov deformations mus tas li, kev kwv yees ntawm cov yas tawg ntawm cov qauv, kev sib tsoo simulations, kev tshawb nrhiav kev ruaj ntseg, cov teeb meem dynamic thiab cov tshuab uas raug rau cov kab mob siab.
Qhov txawv ntawm Viscoelastic thiab Viscoplastic yog dab tsi?
Viscoelasticity thiab viscoplasticity tau piav qhia txog cov khoom ntawm cov khoom siv polymer. Qhov sib txawv tseem ceeb ntawm viscoelastic thiab viscoplastic yog tias cov ntaub ntawv viscoelastic qhia ob qho tib si viscous thiab elastic zog thaum tab tom deformation, thaum cov ntaub ntawv viscoplastic qhia tsis tuaj yeem deformation.
Cov hauv qab no qhia txog qhov sib txawv ntawm cov khoom siv viscoelastic thiab viscoplastic.
Summary – Viscoelastic vs Viscoplastic
Viscoelasticity thiab viscoplasticity tau piav qhia txog cov khoom ntawm cov khoom siv polymer. Qhov sib txawv tseem ceeb ntawm viscoelastic thiab viscoplastic yog tias cov ntaub ntawv viscoelastic qhia ob qho tib si viscous thiab elastic zog thaum tab tom deformation, thaum cov ntaub ntawv viscoplastic qhia tsis tuaj yeem deformation.
