SM490 (tshwj xeeb yog qib B thiab C) muaj txiaj ntsig zoo hauv kev tsim seismic vim nws qhov sib xyaw ua ke ntawm lub zog, lav zoo, thiab weldability, uas yog ib qho tseem ceeb rau cov qauv kom tiv taus cyclic inelastic deformation thaum av qeeg.
Nov yog cov txiaj ntsig tseem ceeb:
1. Guaranteed Toughness & Ductility (Qhov Zoo Tshaj Plaws)
Kev tiv thaiv rau Brittle Fracture: Av qeeg ua rau muaj kev cuam tshuam ntau heev (kev thauj khoom ceev). Cov ntaub ntawv tuaj yeem coj tus cwj pwm nruj dua nyob rau hauv cov xwm txheej zoo li no. SM490B/C qhov yuav tsum tau Charpy tej yam toughness (Ntau tshaj los yog sib npaug rau 27J ntawm 0℃rau B, Ntau tshaj los yog sib npaug rau 47J ntawm 0℃rau C) kom cov hlau yuav nqus tau lub zog tseem ceeb los ntawm yielding thiab deforming ua ntej tej tawg propagates. Qhov no tiv thaiv tam sim ntawd, kev puas tsuaj brittle tsis ua hauj lwm.
Stable Hysteretic Behavior:Thaum muaj av qeeg, cov tswv cuab ntawm cov qauv (xws li beam xaus nyob rau hauv lub sij hawm thav duab) tsim cov yas hinges. Cov pob khawm no yuav tsum tau ua kom loj, rov ua dua ntawm kev khoov (inelastic deformation) yam tsis poob lub zog. Qhov zoo ductility thiab cov khoom sib xws ntawm SM490 pab kom ruaj khovzog dissipationlos ntawm tus cwj pwm hysteretic no.
2. Zoo Weldability nrog Tswjed Chemistry
SM490C muaj cov kev txwv nruj nruj:Nws nta nruj dua tswj ntawm Carbon (C), Sulfur (S), thiab Phosphorus (P), uas ua rau qis carbonSib npaug (Ceq). Qhov no yog qhov tseem ceeb vim tias:
Nws txo qhov kev pheej hmoo ntawm Thaum tshav kub kub-Teb chaws cuam tshuam (HAZ) tawg thaum vuam.
Nws ua kom cov welded sib koom ua ke khaws cov toughness thiab ductility piv rau lub hauv paus hlau. Hauv kev tsim seismic, kev sib txuas feem ntau tseem ceeb dua li cov tswv cuab lawv tus kheej; lawv yuav tsum muaj zog thiab ntau dua ductile.
Predictable Performance:Qhov kev tswj xyuas chemistry no tso cai rau cov kws ua haujlwm kom ntseeg tau tias tus cwj pwm ntawm kev sib txuas welded nyob rau hauv cyclic loads.
3. Sib npaug ntawm lub zog thiab kev ua haujlwm ductility
SM490 muab lub zog tawm los ntawm ntau dua lossis sib npaug rau 325 MPa, muab qib zog zoo los tiv thaiv seismic rog yam tsis tas yuav tsum muaj cov ntu loj.
Qhov tseem ceeb tshaj, nws muaj qhov zoo -txhais tawm los ntawm - mus rau - tensile zog piv (fy/fufy/fu). Seismic codes feem ntau xav tau qhov piv txwv no kom qis dua ib qho kev txwv (piv txwv li, Tsawg dua lossis sib npaug li 0.85 rau qee cov lej) kom ntseeg tau tias cov khoom muaj qhov txaus txaus- muaj peev xwm hardening. Qhov kev ua kom tawv tawv no muab lub zog "tso tseg" tom qab pib tawm los thiab pab cuam tshuam cov yas.
4. Ua raws li cov ntaub ntawv tshwj xeeb ntawm Seismic
Niaj hnub nimno seismic design codes (xws li, AISC 341, Eurocode 8, Japanese AIJ qauv) tswj kev siv cov toughness -guaranteed steels nyob rau hauv seismic quab yuam- tawm tsam systems (SMFs, BRBFs, thiab lwm yam).
SM490B thiab C ncaj qha ua tau raws li cov cai no rau cov khoom siv tawv, qhov SS490 lossis SM490A yuav tsis yog-raws li rau thawj cov tswv cuab seismic.
5. Predictable Inelastic Deformation Peev Xwm
Kev sib xyaw ua ke ntawm cov khoom ua kom ntseeg tau tias cov tswv cuab ua los ntawm SM490 tuaj yeem ua tiav qhov yuav tsum tau muaj ductility yam (μ) thiab kev sib hloov muaj peev xwm teev tseg hauv kev tsim seismic. Qhov no tso cai rau cov kws ua choj ua rau muaj kev ntseeg siab siv lub peev xwm tsim qauv, qhov twg yas hinges tsim nyob rau hauv predetermined, ductile qhov chaw.
Kev sib piv hauv Seismic Context
| Khoom siv | Seismic Suitability | Qhov Tseem Ceeb |
|---|---|---|
| SS490/SM490A | TSIS MUAJ (rau thawj cov tswv cuab seismic) | Tsis muaj guaranteed toughness. Kev pheej hmoo siab ntawm kev tawg ntawm cov pob qij txha welded los yog cov pob khawm yas nyob rau hauv kev thauj khoom ceev ceev. |
| SWB 490B | Haum rau ntau daim ntawv thov seismic. | Muab lub hauv paus toughness (27J ntawm 0 degree) rau lub zog nqus. |
| SWB 490C | Pom zoo heev / Feem ntau xav tau rau cov tshuab seismic tseem ceeb. | Superior toughness (47J ntawm 0 degree) thiab zoo dua weldability (qis Ceq). Muab cov npoo siab tshaj plaws ntawm kev nyab xeeb rau hnyav inelastic deformation. |
Kev siv tswv yim hauv Seismic Systems
SM490 yog siv rau hauv:
Beam-rau-Kem Moment Connections in Special Moment Frames (SMF).
Braced Ncej Cov Tswv Cuab thiab Kev Sib Txuas (tshwj xeeb hauv Buckling-Restrained Braces - BRBs).
Shear Link Beams hauv Eccentrically Braced Frames (EBF).
Cov phaj tseem ceeb thiab Welds hauv cov khoom siv seismic damper.
Kem Splices nyob rau hauv cov dab neeg qis ntawm ductile thav duab.
Xaus
Lub hom phiaj tseem ceeb ntawm SM490 hauv kev tsim seismic yog nws cov ntawv pov thawj toughness, uas ua kom muaj zog, lub zog - nqus tus cwj pwm - tiv thaiv nkig tawg. Thaum ua ke nrog nws zoo weldability thiab sib npaug lub zog, nws muab ib tug txhim khu kev qha, code-raws li cov ntaub ntawv rau tsim fuse zones (yas hinges) uas tiv thaiv tag nrho cov qauv los ntawm dissipating av qeeg zog los ntawm kev tswj deformation. Rau siab - thaj tsam seismicity, SM490C yog qhov kev xaiv zoo dua vim nws muaj zog dua thiab kev tswj xyuas zoo dua.