ktcongban.xls
TRANSCRIPT
TinhCongBxH-PXa (2)kim ton cng bn tit din B x h =3.00x2.70mI. Tnh ton bn np cng:1. Nguyn l tnh ton ni lc bn np cng:- Bn cng c lin kt cht vi phn trn ca thn cng, phn di ca thn cng lin ktngm vi mng. Khi tnh ton ni lc trong bn np khng xt n lc nm ngang ca thncng truyn vo.- V chiu di ln hn 2 ln chiu rng ca tm nn c th tnh theo s hnh 1 . p lc tthng ng do ti trng xe chy gy ra trn nh cng da theo mp vt bnh xe v phn bxung di theo mt gc 45o* Ni lc c tnh ton cho 1m bn thng gc vi chiu xe chy:Ni lc ti gi gia (th trn) v trong nhp (th di) ca bn k 2 cnh c xc nh nh sau:- i vi m men: c c xc nh theo m men ti gia nhp ca dm gin n tng ng:+ tit din gi gia (th trn): Mtt = a.Mo+ tit din trong nhp (th di) : Mtd = b.MoCc h s a, b c xc nh gn ng nh sau :a =1.00; b =0.00Tr s Mo l m men ti gia nhp dm gin n c nhp bng nhp tnh lp ca bn , tng ngvi ti trng thc t 1 m rng bn phi chu. Ti trng ny phi t sao cho Mo l ln nhtMmen tnh ton ti tit din gi gia (th trn) ly gi tr m men ln nht do ti trng gy ratnh theo hai s trn.- i vi lc ct: c xc nh nh dm gin n tng ng* Ni lc c tnh ton vi 2 t hp ti trng :- T hp 1 : Tnh ti, on xe H-30.- T hp 2 : Tnh ti, xe c bit HK-80.2. S kt cu:Hnh 13. S liu tnh ton:- Khu thng thy ca cng lo=3.00m. Chiu cao thng thy ca cng Ho=2.70m- Chiu dy bn np cng h =0.30m. Chiu dy thnh cng t =0.30m- Khu tnh ton cng lp = lo+ h=3.30m. Chiu dy y cng z =0.30m- BT ct thp"10"0c g1=2.50T/m3,Ru=120.00KG/cm2 ,Rch=9.0- Ct thp AII, cng Ra=2800KG/cm2- t p trn cng H =0.15mgo=2.30T/m3,35o- t H30 c trc sau12.00T,Xe nng HK-80 c ti trng trc20T4. Tnh ton ngoi lc:- Tc dng ca tnh ti :H.s vt ti ca t p kt=1.5; ca BT np kb=1.1+ p lc thng ng ca t p trn bn cng:q = go.H.1,0. kt =0.52T/m+ Trng lng bn thn ca bn np:gz = g1.h.1,0. kb =0.83T/m- p lc thng ng do ti trng xe chy gy ra:+ Vi t H30a = a1 + 2.H = 0,2 + 2.H =0.50mb = b1 + 2.H = 0,6 + 2.H =0.90mTrng lng 1 bnh xe sau:Ti tp trung:6.00T. H s vt ti K1 =1.4Ti phn b:24.27T/m2.H s xung kch K2=1+m=1.3Khong cch gia 2 trc bnh xe d=1.90m+ Vi xe nng HK-80a = a1 + 2.H = 0,2 + 2.H =0.50mb = b1 + 2.H = 0,8 + 2.H =1.10mTrng lng 1 bnh xe:Ti tp trung:5.00T. H s vt ti K1 =1.1Ti phn b:10.00T/m2. H s xung kch K2 =1.0Khong cch gia 2 trc bnh xe d=2.70m5. Tnh ton ni lc:- M men un gia tmS phn b tnh ti v p lc xe bnh gia bn+ M men un do tnh ti1.83Tm =182748KGcm+ M men un do hot ti15.56Tm =1556100KGcm8.50Tm =850000KGcmC: l chiu di ca din tch m rng p lc C =b* M men tng cng do tnh ti v hot ti gy ra:SMtt+t = Mtnh + Mt =182748+1556100=1738848KGcmSMtt+HK80 = Mtnh + MHK80 =182748+850000=1032748KGcmV Mtt+t > Mtt+HK80 nn dng ti trng t H30 tnh- Lc ct giS phn b tnh ti v p lc xe bnh gi+ Lc ct do tnh ti2.01T =2013.75KG+ Lc ct do hot ti18.564T =18564KG8.983T =8983KG* Lc ct tng cng do tnh ti v hot ti gy ra:SQtt+t = Qtnh + Qt =2014+18564=20578KGcmSQtt+HK80 = Qtnh + QHK80 =2014+8983=10997KGcmV Qtt+t > Qtt+HK80 nn dng ti trng t H30 tnhNi lc tnh ton ln nht trong hai t hp ti trng l:Mo =1738848KGcmQ =20578KGVy ni lc tnh ton khi c cc h s a, b:a =1.00; b =0.00Mtt = b.Mo =0KGcmMtd = a.Mo =1738848KGcmQ =20578KG6. Thit k mt ct:Bn np cng c tnh theo cng chu un theo trng thi gii hn th nht- Chiu dy lp bo v ct thp d=2.00cmsuy ra: a=d+f/2=3.00cm- Ct thp s dng c ng knh f =20mm- Chiu cao lm vic ho = h - a =27.00cm* Tnh ct thp trong vng chu ko (pha di)0.199Suy ra:0.224Tit din ct thp cn thit l:25.90cm2Chn trn 1m rng bn np cng9.00thanh ct thp f=20.00tit din c g viFa =3.14x9.00=28.26cm2Chiu cao vng nn6.59cm0,55.ho =14.85cmTa c:6.59 Qtt+HK80 nn dng ti trng t H30 tnhNi lc tnh ton ln nht trong hai t hp ti trng l:Mo =1842911KGcmQ =15878KGVy ni lc tnh ton khi c cc h s a, b:a =0.50; b =-0.70Mtt = a.Mo =-1290037KGcmMtd = b.Mo =921455KGcmQ =15878KG6. Thit k mt ct:Bn np cng c tnh theo cng chu un theo trng thi gii hn th nht- Chiu dy lp bo v ct thp d=2.00cmsuy ra: a=d+f/2=2.80cm- Ct thp s dng c ng knh f =16.00mm- Chiu cao lm vic ho = h - a =42.20cm* Tnh ct thp trong vng chu ko (pha di)0.049Suy ra:0.051Tit din ct thp cn thit l:8.00cm2Chn trn 1m rng bn np cng7.00thanh ct thp f=16.00tit din c g viFa =2.01x7.00=14.07cm2Chiu cao vng nn3.75cm0,55.ho =23.21cmTa c:3.75