Thaum cov khib nyiab cuam tshuam nrog ntau yam ib puag ncig, kev hloov pauv tuaj yeem tshwm sim - ob qho tib si sab hauv thiab sab nraud. Ib qho piv txwv yog cov neeg kho tshuab kev ntxhov siab uas tshwm sim hauv plab hnyuv ntawm lub cev. Nws txiav txim siab qhov kev hloov pauv tau thaum muaj kev puas tsuaj.
Basic concepts in physics
Mechanical stress yog ib qho kev ntsuas ntawm lub zog sab hauv ntawm ib yam khoom, uas tshwm sim nyob rau hauv kev cuam tshuam ntawm ntau yam. Piv txwv li, thaum deformation tshwm sim, thaum lub sij hawm uas sab nraud quab yuam sim hloov qhov txheeb ze ntawm qhov hais, thiab sab hauv rog tiv thaiv cov txheej txheem no, txwv nws mus rau ib qho nqi. Yog li, peb tuaj yeem hais tias kev ntxhov siab ntawm kev siv tshuab yog qhov tshwm sim ntawm kev thauj khoom ntawm lub cev.
Muaj ob hom kev ntxhov siab ntawm kev siv tshuab:
- Nco - siv rau ib cheeb tsam ntawm ntu raws li ib txwm rau nws.
- Tangent - txuas rau ntu ntu tangent rau nws.
Cov txheej txheem ntawm cov kev ntxhov siab no ua rau ntawm ib qho yog hu ua lub xeev kev ntxhov siab ntawm lub sijhawm no.
ntsuas hauv pascals (Pa), mechanical stress: tus lej suav yog qhia hauv qab no
Q=F/S, Qhov twg Q yog qhov kev ntxhov siab (Pa), F yog lub zog tsim tawm hauv lub cev thaum deformation (N), S yog thaj tsam (mm).
Txoj khoom ntawm cov khoom khib nyiab
Solids, zoo li tag nrho lwm lub cev, yog tsim los ntawm atoms, tab sis lawv muaj cov qauv muaj zog heev, uas xyaum tsis dhau deformation, piv txwv li. ntim thiab zoo li nyob tas li. Cov khoom zoo li no muaj ntau yam khoom tshwj xeeb uas tuaj yeem muab faib ua ob pawg loj:
- Lub cev.
- tshuaj.
Lub cev muaj xws li hauv qab no:
- Mechanical - kawm lawv nrog kev pab cuam ntawm qhov tsim nyog rau lub cev. Cov khoom no muaj xws li elasticity, brittleness, lub zog, i.e. txhua yam hais txog lub peev xwm los tiv thaiv deformation los ntawm lwm yam.
- Thermal - kawm txog qhov sib txawv ntawm qhov kub thiab txias ntawm ib yam khoom. Cov no suav nrog kev nthuav dav thaum rhuab, thermal conductivity, tshav kub muaj peev xwm.
- Hluav taws xob - cov khoom no cuam tshuam nrog kev txav ntawm cov hluav taws xob hauv lub cev thiab lawv lub peev xwm los sib sau ua ke rau hauv cov kwj deg thaum raug rau lwm yam. Ib qho piv txwv yog hluav taws xob conductivity.
- Optical - kawm nrog kev pab ntawm lub teeb fluxes. Cov khoom no muaj xws li lub teeb pom kev, lub teeb nqus, diffraction.
- Magnetic - txiav txim siab los ntawm qhov muaj lub sijhawm sib nqus hauv cov khoom ntawm lub cev. Rau lawv, nrog rau cov hluav taws xob, lawv teb tsis zoo.them cov khoom vim lawv cov qauv thiab cov lus tsa suab.
Cov khoom siv tshuaj muaj xws li txhua yam cuam tshuam nrog cov tshuaj tiv thaiv rau qhov cuam tshuam ntawm cov tshuaj cuam tshuam thiab cov txheej txheem tshwm sim hauv qhov no. Ib qho piv txwv yog oxidation, decomposition. Cov qauv ntawm cov siv lead ua lattice kuj hais txog cov khoom ntawm cov khoom no.
Koj tuaj yeem xaiv ib pawg me me ntawm lub cev thiab tshuaj lom neeg. Nws suav nrog cov uas tau tshwm sim ob qho tib si raws li kev siv tshuab thiab tshuaj lom neeg. Ib qho piv txwv yog combustion, thaum lub sij hawm hloov pauv tshwm sim nyob rau hauv ob qho tib si saum toj no yam ntxwv.
