Lub hauv paus ntsiab lus sib piv ntawm qhov sib piv dynamic thiab zoo li qub stiffness ntawm cov underrail pads thiab smoothness ntawm siab - tsheb ciav hlau khiav ceev
Vim li cas qhov kev khiav hauj lwm ruaj khov ntawm siab - cov tsheb ciav hlau ceev tau nruj raws li qhov yuav tsum tau ua ntawm dynamic - zoo li qub stiffness piv ntawm hauv qab - tsheb ciav hlau pads?
High-speed trains operate at high speeds, with high-frequency (10-50Hz) and small-amplitude dynamic loads between wheels and rails. If the dynamic-static stiffness ratio of the pad is excessively high (e.g., >1.5), nws txhais tau hais tias qhov dynamic rigidity yog ntau dua li qhov zoo li qhov tawv nqaij - nyob rau hauv siab - zaus dynamic loads, nws coj li "kev txhawb nqa nyuaj," nrog kev poob qis hauv kev co txo kev ua haujlwm. Log-rail cuam tshuam kev vibration yog xa ncaj qha mus rau lub txaj khiav, txo lub tsheb ciav hlau khiav ruaj khov thiab kev nplij siab ntawm cov neeg caij tsheb. Yog tias qhov sib piv qis heev (piv txwv li,<1.1), the pad is prone to excessive deformation under dynamic loads, leading to unstable track geometry, which also affects train running stability and even endangers traffic safety.
Cov khoom siv thiab cov txheej txheem dab tsi feem ntau cuam tshuam rau qhov dynamic - zoo li qub stiffness piv ntawm hauv qab -rail pads?
Hais txog cov khoom siv,roj hmab padsfeem ntau muaj ib tug dynamic- zoo li qub stiffness piv ntawm 1.3-1.5-vim lub viscoelastic zog ntawm lawv molecular chains, lub zog poob tshwm sim nyob rau hauv dynamic loads, thiab stiffness nce me ntsis;polyurethane padsmuaj qhov sib piv qis li 1.1-1.2, nrog rau cov qauv molecular ruaj khov thiab me me sib txawv ntawm qhov dynamic thiab zoo li qub. Structurely, covporosityntawm lub ncoo yog qhov tseem ceeb -cov qauv ntxeem tau tuaj yeem txo qhov sib piv, tab sis qhov porosity siab dhau ua rau qhov tsis txaus zoo li qub; tusthickness thiab puabntawm lub ncoo kuj cuam tshuam rau qhov piv ntawm -thickening lub ncoo txo qhov piv, thiab tshwj xeeb - zoo li tus qauv (piv txwv li, grooves, bosses) optimize kev ntxhov siab faib nyob rau hauv dynamic loads, ua rau dynamic -static stiffness ratio ntau uniform.
Cov kev cuam tshuam dab tsi uas cuam tshuam tsis zoo rau qhov muaj zog ntau dhau - zoo li qub stiffness piv rau qhov siab - khiav ceev?
Ib qho piv txwv ntau dhau ua rau tsis txaus dynamic kev co txo kev ua haujlwm ntawm lub ncoo: ua ntej, nws ua raunce dynamic log-rail rog, exacerbating hnav thiab qaug zog ntawm cov ntsia hlau thiab lub log. Thib ob, siab - zaus vibration acceleratestaug qab txaj hardening(ballastless lem) los yog ballast pulverization (ballasted lem), txo cov kev ruaj ntseg ntawm tag nrho cov khiav. Nyob rau hauv lub sij hawm ntev, kev co yog kis mus rau tus choj los yog tunnel lug, triggeringqauv resonancethiab cuam tshuam rau kev pab cuam lub neej ntawm infrastructure. Cov kev cuam tshuam cov saw no tsis tsuas yog txo cov tsheb ciav hlau khiav ruaj khov tab sis kuj tseem ua rau cov nqi kho tsheb nce ntxiv.
Yuav ua li cas tus nqi tsim nyog ntawm qhov dynamic- qhov sib txawv ntawm qhov sib txawv ntawm hauv qab -rail pads graded kom hloov mus rau siab - tsheb ciav hlau ceev ntawm qhov sib txawv?
Raws li cov qib ceev ntawm qib siab - tsheb ciav hlau ceev, dynamic- zoo li qub stiffness piv txais "qib tsim": rau siab - cov kab ceev nrog qhov ceev ntawm 250 km / h, tus nqi tsim yog1.2-1.3, ntsuas kev ruaj ntseg thiab kev vibration txo; rau 300km / h kab, tus nqi tsim yog1.15-1.25, tsom rau kev txhim kho dynamic vibration txo kev ua haujlwm; rau cov kab nrog kev ceev ntawm 350km / h thiab siab dua, tus nqi tsim yog nruj me ntsis tswj ntawm1.1-1.2, yuav tsum tau hloov qhov nruj me ntsis ntawm lub ncoo nyob rau hauv siab -frequency dynamic loads los xyuas kom meej log-rail contact stability thiab maximize tsheb ciav hlau khiav stability. Qhov kev tsim qauv ntsuas no tau ua tiav raws li cov yam ntxwv ntawm kev thauj khoom ntawm cov tsheb ciav hlau, uas yog ib qho tseem ceeb ntawm kev tsim qauv hauv high -speed track design.
Yuav ua li cas kom paub sai sai seb qhov dynamic - qhov sib txawv ntawm qhov sib npaug ntawm hauv qab - cov tsheb ciav hlau ua tau raws li tus qauv los ntawm "kev ntsuas qhov hnyav" ntawm - qhov chaw?
A poob ceeb thawj tester rau dynamic-static stiffness ntawm khiav padsyog siv, uas muaj peev xwm simulate dynamic load ntawm siab - tsheb ciav hlau ceev cais ntsuas qhov zoo li qub thiab dynamic tawv ntawm lub ncoo. Kev ntsuas qhov tawv nqaij zoo li qub: siv cov khoom zoo li qub (piv txwv li, 10kN), sau lub ncoo deformation, thiab xam qhov tawv tawv. Dynamic stiffness ntsuas: cuam tshuam lub ncoo nrog ib tug poob ceeb thawj ntawm ib tug zaus zaus (xws li, 30Hz) thiab cuam tshuam lub zog, sau cov dynamic deformation, thiab xam cov dynamic rigidity. Qhov piv ntawm ob yog qhov dynamic - zoo li qub stiffness ratio. Yog tias qhov ntsuas tus nqi siab tshaj qhov kev tsim qauv, qhov kev ua tau zoo ntawm lub ncoo yog qhov tsis zoo, thiab nws yuav tsum tau hloov nrog lub ncoo hloov kho kom ntseeg tau tias kev ua haujlwm ruaj khov ntawm kev kub ceev - tsheb ciav hlau ceev.