6. Kev Tsim Qauv Tsim Txheej Txheem
Q1: Cov khoom siv kev nyab xeeb yog siv rau Q35B yeeb nkab qauv?
A1: Cov qauv kev nyab xeeb rau Q35B cov qauv ua raws cov qauv tsim tsim tau (piv txwv li, Eurocode 3, Aisc). Cov feem ib nrab ntawm kev nyab xeeb yog 1.0 rau kev thauj khoom mus tas li thiab 1.5 rau cov khoom siv tau zoo nyob rau hauv lub xeev qhov kev tsim. Cov khoom siv tsis haum yog 0.9-1.0 rau yielding thiab 0.75-0.9 rau buckling. Kev qaug zog tsim kev siv cov ntsiab lus muaj kev nyab xeeb los ntawm 1.15 raws li kev txiav txim ntawm kev ua tsis tiav. Cov seismic tsim yuav ua haujlwm txo cov yam (0.85) rau cov khoom siv zog. Cov xwm txheej no rau cov khoom hloov pauv, thauj tsis meej, thiab siv thev taus. Cov ntawv thov tseem ceeb tshaj plaws (nuclear, sab nrauv) siv ntau yam dua.
Q2: Yuav ua li cas bhaling tsis kam suav rau Q355B kav?
A2: Buckling tsis kam txiav txim siab ob qho tib si hauv zos thiab ntiaj teb booj. Hauv zos buckling xyuas cov kab uas hla-rau-tuab (d / t) piv rau kev txwv (feem ntau 90 rau chav kawm 1 ntu ntawm eurocode). Ntiaj teb buckling siv cov slenderness piv (L / R) nrog Perry-Robertson cov mis sau nyiaj rau kev tsis txaus ntseeg. Cov txo qis qis (λ) txiav txim siab buckling nkhaus (feem ntau nkhaus "a" rau Q355B). Finite elate tsom xam (fea) tuaj yeem pab cov txheej txheem rau cov geometries complex. Txias-tsim ntu muaj 10-15% qis buckling tsis kam vim yog tsim cov teebmeem. Dabtsi yog khoov-torsional buckling yuav tsum tau cais cov tshev rau cov ntu tsis-ncig.
Q3: Dab tsi yog txoj kev sib txuas raug rau Q355B yeeb nkab qauv?
A3: Cov hau kev sib txuas muaj xws li welded pob qij txha (pob tw, ntsaws, qhov muag), bolted flange sib txuas, thiab cov neeg kho tshuab txuas. Welded pob qij txha muab lub zog siab tshaj plaws thiab txhav tab sis yuav tsum tau txawj ntse. Flanged kev sib txuas cia pub Disassembly tab sis nce phaus thiab nqi. Cov neeg kho tshuab theem (wataullic-style) muab kev teeb tsa ceev rau cov qauv ib ntus. Cov kev sib txuas tshwj xeeb zoo li lub sijhawm-tawm tsam cov ntshav yuav tsum tau paub cov ncauj lus kom ntxaws kev tsom xam. Kev sib txuas tsim yuav tsum xav txog kev thauj khoom, lub neej qaug zog, thiab kev tiv thaiv kev tiv thaiv corrosion tiv thaiv txuas ntxiv.
Q4: Cov Hluav Taws Xob Hluav Taws Xob cuam tshuam li cas Q355B yeeb nkab ua haujlwm?
A4: Q355B loses strength rapidly above 400°C, retaining only 50% yield strength at 550°C. Critical structures require fire protection like intumescent coatings (1-3hr ratings), concrete encasement, or mineral wool insulation. Unprotected steel reaches critical temperature (538°C) in 15-30 minutes during standard fire tests. Fire engineering approaches may use natural fire curves instead of standard curves for realistic assessment. Post-fire inspections check for permanent distortion (>L / 20 xav tau hloov).
Q5: Dab tsi yog kev txiav txim siab txog Q355B yeeb nkab qauv?
A5: Kev tsom xam muaj zog yog qhov tseem ceeb rau cov qauv yuav ua rau cua, tshuab, lossis cov khoom siv neeg taug kev. Tej zaus ntuj ntau zaus yuav tsum nyob sab nraud 2-8hz ntau kom tsis txhob muaj tib neeg - kev co. Damping piv yog feem ntau 0.5-2% rau welded steel qauv. Cov tshev nyiaj rov qab acoustic resonance xav tau rau cov tshuab luam ntawv. Kev sib cais kev cais (roj hmab nce, tued loj dampers) mitigates muaj teeb meem teeb meem. Qaug zog lub neej suav hauv kev co raws cov me me txoj cai nrog tus nab tsim nyog.
