8 xac dinh US uon cho phep va Us tiep xuc cho phep trong TDBR

- US tiep xuc cho phep

[@H]= @Hlim.ZR.ZV.KL.KXH/SH

( cac Hlim, R, V L,XH,H viet nho xuong duoi')

voi @Hlin: gioi han ben moi tiep xuc cua mat rang

SH: he so an toan = 1,2 hoac 1,1

ZR: he so anh huong cua do nham' be mat ZR=0.95

ZV: he so anh huong cua van toc ZV=1,1

KL: he so anh huong cua boi tron KL=1

KXH: he so anhhuong cua kich thuoc banh rang KXh=0,9

tinh so bo thi coi ZR.ZV.Kl.KXH=1

- US uon cho phep

[@F][email protected]/SF

@Flin: gioi han ben uon cua rang ung voi chu ky chiu tai NF1( F1 viet nho xuong duoi)

SF : he so an toan

YS: he so anh huong cua kick thuoc banh rang=1,08

YR: he so anh huong cua do nham mat luon chan rang

YR=1,05toi 1,2

KXF he so anh huong cua kickthuoc KXF=1