Kunyamula kwa chonyamulira kumakhala kochepetsedwa pafupifupi nthawi zonse ndi kupindika kwa gawo lopanikizika. Izi zimachitika pokhapokha pamene malire a kufewa afika, pambuyo poti nkhawa zafanana paliponse mu gawo lopanikizika. Ndi pokhapokha ndi kuthandizidwa mwamphamvu m’mbali komwe kupsinjika kwa m’mphepete komwe kungakhale kupirira kungakwezedwe kufika pa dera la kulimbitsidwa kwa chitsulo cha zomangamanga. Poyesa mphamvu yonyamula, kugawa kwenikweni kwa nkhawa kuyenera kuganiziridwa. Ngati tingaganize kugawa kwa nkhawa molunjika, mphamvu yonyamula ingachepetsedwe mopitirira muyeso. Zochitika za kusakhazikika ziyenera kufufuzidwa makamaka.
Kuchotsera mabowo mu mizati yonyamula katundu pa kupindika
Pa mbali yomwe ikutambasulidwa ya chothandizira pamakhala kufooka kwa gawo ngati mmene zilili pa ndodo zotambasulidwa (kung’ambika kwa gawo lotambasulidwa pa gawo lofooka). Pa kukana mabowo m’lingaliro limeneli amagwiritsidwa ntchito malamulo ofanana ndi a ndodo yotambasulidwa.
Popeza mabowo odzazidwa ndi ma riveti pa mbali yopanikizidwa ya chonyamulira amakhudza pang’ono kwambiri kagawidwe ka kupsinjika ndi kusokonezeka, ndipo mphamvu yonyamula nthawi zambiri imaletsedwa ndi kupindika kwa m’mbali kwa lamba wokanikizidwa, kukula kwa kufooka kwa gawo pa chonyamulira cha magawo ofanana sikukhudza kwambiri katundu wotengedwa. Choncho kale F. Hartmann anafunsa ngati kuli kofunikira n’komwe kuwerengera kufooka chifukwa cha mabowo pa zonyamulira zofanana. Pa magawo osafanana (mbali yopanikizidwa ndi yolimba kwambiri) kuchotsera mabowo pa mbali yokokedwa ya chonyamulira kungakhale kofunika pa mphamvu yonyamula. Pansi pa katundu wobwerezabwereza, mabowo amakhala ndi mphamvu yayikulu, ngakhale ali patali kwambiri ndi ulusi wa m’mphepete.
Lero pakuwerengera mphamvu yonyamula ya gawo pa kupinda amagwiritsa ntchito gawo lonse ndi gawo loyera (kuphatikiza mitundu ina yonse yofunika ya kusweka). Kusweka pa gawo lonse kumachitika pa gawo la gawo lomwe silinafooketsedwe ndi mabowo. Kusweka pa gawo loyera kumachitika pa gawo lomwe laphweketsedwa ndi mabowo, ndipo dera lomwe limaganiziridwa ndi dera lonse lochepetsedwa ndi dera la ma opening onse.
Mabowo m’khosi ndi m’mutu
Pakupindika, kuwonjezera pa zovuta zoyima, pamawonekeranso zovuta zosenda, zomwe pa zonyamulira zokhala ndi zingwe zofanana ndi pamwamba zimakhala zogwirizana ndi mphamvu yopingasa Q. Pa magawo ovuta, zovuta zosenda pa malo okhudzana pakati pa mbiri za valani zosiyanasiyana zimalandiridwa ndi ma riveti omwe amawalumikiza. Kugawika kwa mphamvu zosenda T mu nthiti ndi kwa parabola, ndipo m’mizere ya pamwamba kumakhala pafupi ndi mzere wolunjika. Pa zonyamulira zokhala ndi mizere yolemera, T mu nthiti imasiyana pang’ono ndi mtengo wapakati Tm, womwe nthawi zambiri umakhala wokwanira pa kuwunika koyamba.
Chith. 1
Zivundikiro pa mutu (chith. 1b) ayenera kulandira pamodzi mphamvu ya msomali TK < TH. Mphamvu ya msomali pakati pa ma lamela a lamba osiyanasiyana ndi yocheperapo ndipo pa nkhani yasonyezedwa pa chith. 1c imafalikira ku chiwerengero chochuluka cha ma riveti.
Kupitiriza kwa chonyamulira
Kutambasula kwautali kwa chitsulo choyima kumafunika pamene kutalika kwa chitsulo kuli kwakukulu kuposa m’lifupi mwa zitsulo zomwe zilipo. Kungakhalenso kofunika chifukwa cha kupanga ndi mayendedwe. Zomangira ndi ma riveti mu kutambasula kwautali kwa chonyamulira chimodzi ziyenera kulandira mphamvu yomweyo TL, yomwe chitsulo chosatambasulidwa chikanakhala nayo pa cholumikizira chautali. Popeza kufooka chifukwa cha mabowo mu zomangira kuli kofanana ndi kwa chitsulo choyima, makulidwe a zomangirazo ayenera kukhala akulu kuposa kapena ofanana ndi makulidwe a nthiti.
Sl. 2 - Kuwonjeza kwautali kwa pepala loyima lachitsulo
Kulumikizana kwa mbali pansi pa katundu wa kupindika kungaphimbidwe m’njira zosiyanasiyana ndi ma podvezice. Sl. 3 ikusonyeza mwayi wambiri wa kulumikizana kwa m’fakitale, mmene pepala loyima lokha ndilo limapitilira. Ngati ma podvezice ali pakati pa ma ngodya a pojas (sl. 3a), zidzatsala mizere ya pepala loyima pansi pa ma ngodya a pojas osaphimbidwa. Kenako ma ngodya ndi ma riveti m’dera la kulumikizana kwa pepala loyima amakhala olemedwa kwambiri, choncho mtundu uwu wa kulumikizana uyenera kuchepetsedwa ku kulumikizana kosafunika kwambiri komwe kuli ndi mphamvu zochepa. Nthawi zonse ayenera kusankhidwa kulumikizana komwe kwaphimbidwa kwathunthu. Ma podvezice apadera pa mikono yoyima ya ma ngodya amalandira ma stress a m’litali a mzera umenewu, koma amatenga nawo mbali pang’ono kwambiri pa kulandira mphamvu ya m’mbali. Kusintha kwina pa izi kumabwera ndi sl. 3c. Pa mphamvu zazikulu ayenera kufunidwa ma podvezice pa kutalika konse kwa pepala loyima (sl. 3d), zimene zimatanthauza kuti ma ngodya a pojas ayenera kudulidwa. Ma podvezice amatenga makulidwe a mkono wa ngodya, ndipo pa makulidwe akulu a ma ngodya amagwiritsidwa ntchito ma padzera olinganiza kuti asawonongeke ndi makulidwe ochulukira a podvezice.
Sl. 3 - Kulumikizana kopyola (kwa m’mafakitale) kwa chitsulo choyima
Kumapeto kwa chitsulo choyima chomwe chili pansi pa katundu wa mphamvu yodutsa mbali: Chonyamuliracho pa malo olumikizidwawo chili ndi katundu wokha Q (M = 0). Kwa kulumikizana komwe kuli ndi mipata yofanana ya ma riveti (sl. 4) tiyenera kuganiza kuti mphamvu mu ma riveti NiQ zimagwirizana pafupifupi ndi gawo loyenera la pamwamba e*t la cholumikizira, ndiko kuti mphamvu mu ma riveti zimagawidwa mofanana ndi zovuta za kukameta pa kutalika kwa chonyamulira, NiQ = e*t*τi = e*Ti. Komabe pa kukula kwake amawerengera kugawa kofanana pa ma riveti onse n, NiQ = Q/n.
Chith. 4 - Kupitiliza kwa pepala loyima ndi kugawa kwa mphamvu yodutsa
Sl. 5 p_rikazuje kuwonjezera kwa msonkhano_ wa pepala loyima (ma angle ndi ma lamela olunjika apitirizidwa kwina).
Chith. 5
Kupindika limodzi ndi mphamvu ya normal: Othandizira omwe panthawi imodzimodzi ali ndi ma moment a kupindika ndi mphamvu za normal amawerengedwa malinga ndi mfundo zomwezo ndi poganiza kuti kupanikizika kugawa mowongoka. Pakachotsedwa kwathunthu ma riveti mu ma flange onse awiri, gawo lothandiza ndi malo a mzere wa zero sizidalira mtundu wa katundu, choncho kupanikizika kochokera ku M ndi N kungowonjezedwa mwachindunji. Katundu pa ma riveti m’gawo lotsatira umapezeka ndi kuphatikiza mphamvu kuchokera ku milandu ya katundu ya magawo M, kapena N.
Kuthandizira ndi kulumikiza kwa chonyamulira
Pano tidzakambirana kokha yankho limodzi lodziwika kwambiri pakati pa mayankho ambiri. Poyesa, nthawi zonse muyenera kuganizira za mphamvu zowonjezera zomwe zimachokera ku kusiyana ndi mawerengedwe a mphamvu omwe ali okhazikika kwambiri kapena ochepa kwambiri.
Kugwirizanitsa kosavuta kwa chonyamula pa pa lamba wapamwamba wa chinthu china cha zomangamanga kumaganiziridwa pamene pali kutalika kwakukulu kwa zomangamanga komwe kulipo. Nthawi zambiri pamakhala kulumikizana kolimba ndi ma riveti kapena ma bolt. Pa chith. 6 kwasonyezedwa kugwirizanitsa kwanthawi zonse kwa ma I-rožnjača opitirira m’kumanga nyumba, komwe kumapewanso kubowola m’mapazi aang’ono a I. Zonyamula ziyenera, pakafunika, kutetezedwa ku kugubuduka komanso ku mphamvu zodutsa m’mbali (chith. 7 ndi 8). M’makampani a milatho, zonyamula nthawi zambiri zimaphatikizidwa awiri awiri (chith. 9); kugwirizanitsa kosasunthika kwa chonyamula cha m’litali pa chonyamula cha m’lifupi (chith. 10). Zonyamula ziyenera, pamene pali mphamvu zazikulu zothandizira, kulimbikitsidwa ndi ngodya zoyikidwa bwino kapena ma profayilo owotcherera (chith. 8 mpaka 10). Pa zonyamula zovuta, katundu uyenera kuperekedwa m’mbavu.
Chith. 6 - Kumangirira ma rožnjača
Sl. 7 ndi 8
Chith. 9 ndi 10
Kulumikizana kwa nthiti: Pa chith. 11 ndi 12 zasonyezedwa zolumikizana za I-mitengo, zomwe zimagwiritsidwa ntchito pa zomangamanga ngati zolumikiza wamba. Kudula kumalandira kuzungulira kwakukulu kuti apewe kusweka kwa nthiti ya chonyamulira. Kukhoma kwa elastic pa kulumikizana kwa nthiti kumabweretsa kuwonjezeka kwina kwa mphamvu yonyamula. Kusokonekera kofotokozedwako ndi kopanda ngozi pamene katundu uli wambiri bata, monga, mwachitsanzo, pa milatho yakale.
Sl. 11. - Kulumikizana koyenera kwa I-nosa yokhala ndi mapeto odutsa molunjika
Chith. 12 - Zolumikizira wamba zokhala ndi malekezero odulidwa a I-girida
Zolumikizira zolimba pa kupinda zimapangidwa pamene pakufunika kulumikizana popanda kusintha kwa ngodya (othandizira opitirira, ngodya zolimba za chimango) kapena pamene pali chiopsezo cha kusweka chifukwa cha kutopa pa katundu wosiyanasiyana, makamaka pa milatho ya njanji. Mungagwiritse ntchito ma lamela a continuity, zolumikizira zolimba pa kupinda. ngodya zolimba pa kupinda, ngodya za chimango.
- Malamulo a continuity a lamela – Ngati pakufunika kulumikiza zonyamula katundu zomwe zili pa ndege imodzi, ndiye kuti ma upper flanges onse awiri amalumikizidwa ndi lamela kapena lamba wa continuity. Choncho ma rivet a cholumikizira amatulutsidwa ku mphamvu za kukoka ndipo kusokonekera kwakukulu kumapewedwa.
Sl. 13 - Kulumikizana ndi lamela la kupitiriza
Chith. 14 - Kulumikizana kwa zonyamulira zazitali a) mlatho wa msewu waukulu; b) mlatho wa njanji
- Malumikizidwe olimba pa kupinda – Mtundu uwu wa malumikizidwe umapezeka pa makhonzo olimba a misewu ya anthu oyenda pansi pa milatho ya msewu. Pa ma momeni ang’ono, mbale yake yowongoka imamangiriridwa kokha pakati pa ma angle a kulimbitsa mtengo waukulu. Momeni wolowetsedwa umagawidwa kudzera mu kulimbitsa mpaka pa kutalika konse kwa mtengo waukulu, kapena umalowetsedwa m’magulu ake ngati mgwirizano wa mphamvu.
Chith. 15 ndi 16
- Makona olimba pa kupindika – Makona olimba pa kupindika pakati pa mizati ndi ma beam othandizira m’nyumba ayenera kukonzedwa moti ngodya isasinthe ndipo pasakhale kupitirira kwa kupsinjika komweko kulikonse. Maulalo odalirika m’makona amapezeka, mwachitsanzo, malinga ndi chith. 16 pamene amagwiritsa ntchito ma sheet a m’mphepete kapena malinga ndi chith. 100 pamene mphindi ya kulowerera mu zigawo za mzati imatengedwa ngati mgwirizano wa mphamvu.
- Mikona ya chimango – Pa mafelemu a polygonal, cholumikizira chingapangidwe pa malo opindika ngati kusiyana kwa ngodya kuli kochepa; ndodo zolumikizidwa zimakutidwa ndi ma tie monga ndodo zotambasulidwa ndi zopanikizidwa. Mphamvu zopotoka zimasonkhana pa malo opindika ndipo ziyenera kulandiridwa ndi zolimbitsa. Pa sl. 101 muyenera kuwona kusiyana mu kukutidwa kwa cholumikizira ndi kulimbitsa, kutengera njira ya mphindi yokhotakhota ndi mphamvu zosokoneza. Pakakhala mphamvu zazikulu ndi kusiyana kwakukulu kwa ngodya, zimapewa kuti cholumikizira chifike ku gawo la chimango lokhotakhota kwambiri. Zolumikizira pafupi ndi ngodya za chimango zimapereka mawonekedwe abwino a zomangamanga ndipo zimathandiza kupanga mosavuta. Zitsanzo za zolumikizira zapadziko lonse zokhomedwa kumbali zonse ziwiri za malo opindika zikupezeka pa sl. 102a ndi sl. 102b, pomwe ngodya imapangidwa ndi gawo lowotcheredwa. Pa sl 103 ikuwonetsa kulumikizana kolimba pa kukhotakhota kwa nsanamira ya chimango ndi chopingasa chopitirira.
Chith. 17a
Chith. 17b
Zolumikizira zopingasa: Pa zolumikizira zomwe takambirana mpaka pano, nthiti zinali zoyimilira zopingasa wina kwa mzake. Koma ngati ngodya si yolunjika, ndiye ma angle (chith. 18) amatembenuzidwa, ndipo pa ngodya zakuthwa kwambiri amagwiritsa ntchito ma wedge spacers. Gwiritsani ntchito ma tie a continuity ndi zidutswa zothandizira m’njira imeneyo monga pa zolumikizira zolunjika. Ma plates a kulumikiza opindika (chith. 19) amalumikizidwa ndi eccentricity yayikulu ndi mphamvu zowonjezera zazikulu. Kupanga zolumikizira zopingasa kumakhala kosavuta pamene amagwiritsa ntchito ma plate olumikizira owotcheredwa (chith. 20).
Chith. 18
Chith. 19
Chith. 20