theem peb yog cheeb tsam caj dab. Tshaj li lub zog tensile, lub caj dab tsim qhov chaw hauv cheeb tsam cross-sectional ua me dua qhov nruab nrab. Lub caj dab deformation yog heterogeneous thiab yuav ntxiv dag zog rau nws tus kheej raws li qhov kev ntxhov siab concentrates ntau dua ntawm qhov me me.
thaj chaw caj dab yog dab tsi?
Necking, hauv engineering lossis cov ntaub ntawv tshawb fawb, yog a hom ntawm tensile deformation qhov twg ntau cov strain localize disproportionately nyob rau hauv ib cheeb tsam me me ntawm cov khoomQhov ua rau muaj kev txo qis hauv zos ntu ntu ntu muab lub hauv paus rau lub npe "caj dab ".
Yuav ua li cas yog lub caj dab ntawm cov khoom siv ductile hauv daim duab qhia kev ntxhov siab?
Tom qab mus txog qhov kawg ntawm kev ntxhov siab, cov qauv ntawm cov khoom siv ductile yuav nthuav tawm lub caj dab, uas nyob rau hauv qhov chaw hla ntu hauv cheeb tsam hauv cheeb tsam ntawm cov qauv txo qis. F: Qhov no yog qhov tawg taw teslossis qhov tawg, uas yog qhov chaw uas cov khoom tsis ua haujlwm thiab sib cais ua ob daim.
Qhov tseeb ntawm caj dab yog dab tsi?
Necking lossis localized deformation pib ntawm qhov siab tshaj plaws load, qhov twg qhov nce hauv kev ntxhov siab vim qhov txo qis hauv qhov chaw hla ntawm cov qauv ua ntau dua li qhov nce ntawm qhov muaj peev xwm nqa tau ntawm cov hlau vim qhov hnyav hnyav.
Koj ua li cas thiaj li muaj kev ntxhov siab tiag?
True stress=(engineering stress)exp(true strain)=(engineering stress) (1 + engineering strain) where exp(true strain) yog 2.71 tsa rau lub zog ntawm (qhov tseeb strain).
