cau 10: muc dich buoc tinh kiem nghiem truc. giai thich va neu ro phuong phap xac dinh cac thong so cong thuc tinh heso va an toan truc. neu cac giai phap khi khong dam bao he so an toan

* kiem nghiem truc la buoc tinh can thiet ke kiem tra do ben moi , do ben , do cung vung cua truc. khi xac dinh so bo duong kinh truc ta moi chi xet den tacx dung cua momen xoan chua xac dinh cu the tac dung cua momen uon. tinh qua viec giam [To]

chua xet toi 1 so yeu cau anh huong nhu dac  tinh thay doi chu ly ung suat . su tap trung ung suat , yeu to kich thuoc, chat luong be mat.... vi vay sau khi dinh ket cau truc can tien hanh kiem nghiem

* cong thuc tinh he so an toan

s= [email protected]/(can(s@^2+sto^2) >= [s]

"-1 viet nho"

s@= (@-1)/(k@.@a/(beta.ep@) + #@.@m)

sto= (to-1)/( kto.toa/(beta.epto) + #to.tom

* khi khong dam bao he so an toan

- s<[s]

ta co the

+ tang duong kinh truc

+ su dung vat lieu ben hon

+ giam khoang cach cac doan truc neu co the

+ su dung cac bien phap cong nghe nhu lam goc luon de tranh su tap trung ung suat

- s>>[s]

ta co the

+ giam duong kinh truc

+ su dung vat lieu re hon