Ko te tāpiritanga te ingoa o ngā hononga e whakamahia ana mō te whakawhānui, mō te whakanui rānei. Hei tauira, e hiahiatia ana ngā tāpiritanga nā te mea kāore e rahi ngā roa hurihia, ngā whānui rānei o ngā pepa, ā, i te tāuta ka hiahiatia hei whakawhāiti i ngā āhuatanga me te taumaha o ngā wāhanga takitahi e kawea ana. Ko ngā here te ingoa o ngā pepa e taupoki ana i te wāwāhi i te tāpiritanga. Ko ērā atu hononga katoa, otirā ko ngā hononga i waenganui i ngā tokotoko o te kūaha i ngā ahunga rerekē me ngā kaikawe i ngā papa rerekē, ka kīia he hononga.
Mō ngā hononga noa ka rahia ngā here me ngā riveti o ngā tāpiritanga kia rite ki te kaha katoa. Nō reira, i te tāpiritanga noa kāore e hiahiatia kia pā atu ngā mata o ngā tāpiritanga tētahi ki tētahi.
Ko te tino wāhi whakamahi o ngā tokotoko tō me ngā tokotoko pēhi (arā, he tokotoko tika ēnei e utaina ana te nuinga e ngā kaha tōtika) ko ngā whitiwhiti. Ka waiho e ngā kōrero o tēnei wāhanga ki waho te mōrearea o te korukoru o ngā tokotoko pēhi. Tuatahi ka tirohia te kaha pateko.
Te tangohanga mō ngā rua i roto i ngā rākau tō
Te kaha kawe: Kua tino huringa ā-rohe te āhua o te taumahatanga i roto i te rākau tōtika nā ngā kohao/whakatuwheratanga. I te rohe o te ōwehenga tōtika ka ōrite te tohatoha taumahatanga ki te wāhanga kua ngoikore (whaka. 1). Ko te taumahatanga tōtika roa nui rawa i roto i te rākau tapawhā, e ai ki a A. Henning:
maxσ = σm*[3-(d/b) + 0,8(d/b)2]
Whaka. 1 - Ngā taumahatanga ā-roa me ā-whiti i roto i te tokotoko kōhao a) e ai ki a A. Henning; b) e ai ki a M. Rudeloff
I te take tepe d/b = 0 o ngā lamela tino whānui, ka puta mai i reira maxσ = 3σm, ā, mō te take e whakaaturia ana i te wh. 1a d/b = 1/3 ko maxσ = 2,42 σm. Haunga te pēhanga roa, kei reira anō ngā pēhanga whakawhiti me ngā pēhanga kutikuti. Kei te taupoki o te kohao te taumahatanga nui rawa. I reira ka puta tuatahi mai ngā huringa pūmau, arā, ka whatiwhatia ngā tihi o ngā pēhanga, ā, ka puta te ōritetanga pēhanga puta noa i te wāhanga whakawhiti. Ka puta noa ngā huringa pūmau ka kitea i te takiwā o ngā kohao inā nui ake te pēhanga toharite σm i te wāhanga ngoikore i te rohe totoro σFO. Ko te toronga katoa o te rākau i te SF = Fm * σF he iti noa iho te nui ake i tō te rākau kāore ōna kohao. (Fm ko te horahanga o te wāhanga ngoikore rawa)
I ngā whakamātau tōanga me ngā tokotoko kua rivetia, ka puta tonu te whati i ngā wāhanga kua ngoikore. Ko te kawenga i te wā o te whati, i ngā āhuatanga noa, e tika ana te kī SB = Fn * σB. Ko ngā whakamātau whati i ngā tokotoko tōngā me ngā kohao tuwhera i whakaatu ngā āhua o te whati pēnei i te pikitia 2.
Whika 2 - Ngā whakaahua o te whati o ngā rākau tō
Experiments with riveted joints have shown that splices with straps with one row of rivets have lower resistance than splices with several rows of rivets one behind another. Accordingly, the average stress at failure σB in the effective cross-section amounted to:
Te tukanga tāhuahua mō ngā rākau tōtika: E ai ki te tikanga tātai noa, me ū te taumahatanga tōtika toharite ki σm = S/Fm ≤ dozσ, ā, i roto i ngā wāhanga whaitake katoa Fm. Ka whakatauria te tango o ngā kohao mō te wāhanga poutū e nui rawa ana ngā kohao, ā, tērā pea ka puta ko te wāhanga whati me te nui ake o ngā kohao he uara iti ake mō Fm (whaka. 2). I taua tikanga, mō ngā kōtaha kua hurihia ka tātaihia a Fm mā te whakawhanake. Ki ngā wāhanga matatini ka whakahaeretia i taua anō aronga.
Ko te ōwehenga Fm/F e takoto ana i waenga i 0,8 me 0,9, arā, ko te tangohanga o ngā kohao ΔF = F – Fm e rite ana ki 10% ki 20% o te whiti whānui F o te tokotoko. I ngā hanganga nui ka tino pā a ΔF ki te taumaha, nō reira he mea whai hua te kimi whiti he iti ake te tangohanga o ngā kohao.
Ngā huringa ā-āhua: He iti noa ake te toronga rapa o ngā tokotoko tōngāmimi me ngā kohao i te toronga o ngā tokotoko ōrite kāore i kōhao. He tata tonu te ōrite o te toronga katoa o ngā tūhono ki tō ngā lamella kua tāpiritia. Nō reira he rawaka kia whakatauria, mō te tātaitanga o ngā huringa āhua o ngā hanganga rino, ngā toronga rapa me ngā uara E me F o ngā tokotoko kāore i ngoikore. He nui ake te haumaru ki te rere whakapā i ngā tokotoko kua ngoikore i tō, hei tauira, ngā tokotoko kōpeke.
Te tohatoha o ngā kaha i roto i ngā rivet
Whaka. 3
Ko te tohatoha o te kaha S i roto i te tokotoko ki ngā rivet takitahi o te hono ka whakawhirinaki ki ōna āhuatanga rapa; he “kāore i te tautuhia ā-tatauranga”. I te take o sl. 3 ka whakawhirinaki te tohatoha o N1, N2, … ki te whakakoretake o ngā rivet me ngā papa kua hono, ā, ka rerekē i runga i te ōwehenga Fpodvezice/Fštapa. Mō Fpodvezice ≠ Fštapa kāore ngā kaha pito i roto i ngā rivet e ōrite anō te nui (sl. 50a). I te hekenga o te ōwehenga Fpodvezice/Fštapa ka iti ake a Nn, ka whakatata a N1 ki a S. Kāore i te tika te hono i ngā lamela tino rerekē te matotoru (sl. 4b) nā te nui rawa o te kawenga ki te rivet tuatahi.
Wh. 4 - Te kawenga o ngā nati mō Fštap > Fpodvezice
He mārō ngā lamela me ngā here, ko ngā rivet anake he ngohengohe (whaka. 5a). Nō reira ka whiwhi te katoa o ngā rivet i te piko ōrite, me ōrite katoa ngā kaha kei roto i ngā rivet.
He mārō ngā nati, ko ngā pereti me ngā here anake he ngāwari (wh. 5b). I te mea me ōrite ngā whakaroanga i roto i te tokotoko me ngā here i waenga i te nati tuatahi me te nati whakamutunga, ka whai ake ko N2 = N3 = … = Nn-1 = 0, haunga N1 = S * x1.
Wh. 5
Kei waenganui te tohatoha tūturu o ngā kaha i ēnei take pae. Mēnā ka piki ake te kawenga, ka puta tuatahi te whakakoretake pūmau i ngā rivet pito, ka whakangāwaritia ngā rivet e tino kawengia ana, ā, ka nui ake te ōrite o te tohatoha o ngā kaha. I muri i te putanga o ngā whakakoretake nui ake, ka whakatata te tohatoha o ngā kaha ki te take e mārō ana ngā lamela me ngā here, arā, ka tata ōrite katoa ngā kaha i roto i ngā rivet, mēnā ko te kutikuti o ngā rivet te mea matua.
Utanga i te wā pakaru: Ko te āhua o te whiu i ngā rivet he iti noa tōna pānga ki τBV. Ko te kaha kutikuti τBV o te tūhono he tino motuhake i te maha o ngā rivet, i tō rātou whakaritenga, i te āhua o te tūhono rivet; e tino āhua rite ana te utanga i te wā pakaru ki te utanga taurite o ngā rivet katoa. Ko ngā kōrero ōrite e whai mana ana hoki mō ngā tūhono tīwiri noa, nō reira ka taea te whakatau kāore te ātete ki te retireti e tino pā ki te kaha kawe.
Whakatau rahinga: I ngā hanganga maitai me ngā tokotoko e utaina pokapū ana, ka tatauria mā te tohatoha ōrite, arā, N = S/n mō ia rivet. Nā te mea i ngā toronga roa ka tōmua te tino utaina o ngā rivet tuatahi, me karo, mēnā ka taea, te neke atu i te 6 rivet kia kotahi te rarangi.
Te ātete ki te paheke: Ka puta kē te paheke i ngā hononga i raro noa iho i tētahi kawenga āhua iti. Ko te ātete ki te paheke ka whakawhirinaki i te tuatahi ki te kaha whakamau, e rerekē ana i raro i ngā awe maha. Ka noho koretake tēnei i te rahi-hoahoa o ngā hononga ki ngā tāoke me ngā tīwiri i whakamahia nuitia rā anō. E tohutohutia ana ngā hononga ki ngā tīwiri kaha-teitei.
Te tohatoha o ngā kaha i ngā riveti puta noa i te whānui: Ina ōrite ngā tawhiti o ngā riveti, pūtahi ki te ahunga o te kaha (whakaahua 6a), ka riro mā ia riveti ētahi rīpene whānui ōrite a o te wāhanga whiti, nō reira i te whakatata tuatahi he ōrite te rahi o ngā kaha i ngā riveti N = a t σ. He āta kore-whakamārama te tohatoha ina kāore ngā tawhiti o ngā riveti i te ōrite; mō te take i te whakaahua 6b, ka mahia i runga anō i te ture o te rewa.
Fig. 6
Kaho tōtika
Haere Tonu: He haere tonu me ngā here taurite (wh. 3 me 4). Ko te kaha S i te tokotoko i te wāhi o te haere tonu me kawe e te here anake. Me whakarite anō ngā niao i te haere tonu kia rite ki a S, nā te mea me whakawhiti e rātou te kaha katoa mai i te tokotoko kua toroa ki ngā here.
Ko ngā pito hono me te here kotahi-taha e whai pānga ana ki ngā taumahatanga piko tāpiri nui i roto i ngā pepa kua hono, ngā here me ngā rivet. Ka whakamahia te uhi kotahi-taha o ngā pito hono nā ngā whakakēnga nui anake i aua wā (sl. 7) ina mārō te rākau ki te piko, ina rānei kei te puritia taha kia kore e taea te piko.
Whaka. 7
Hononga takawaenga – Ina kāore e taea te whakatakoto tika ngā here ki runga tonu i ngā pepa kua hono, ka nui ake ngā taumahatanga piko o ngā rivet me ngā pepa. Nō reira, i runga anō i te maha m o ngā paparanga takawaenga, ka kōwhiria he maha nui ake n’ o ngā rivet i te maha n i te taupoki tika o ngā hononga.
Whaka. 8
I ngā wāhanga matatini ka whakaraupapatia ngā taura here kia karo ai i ngā pikinga ā-rohe o ngā taumahatanga, nō reira ka whakatauria ngā mata takitahi o ngā taura here kia rite ki te mata o te wāhanga o te whitinga ka taupokina e rātou, mehemea ka taea, me te pupuri tonu i te tūranga o te pūtake-taumaha. Ko ngā tohatoha mata o ngā taura here e rerekē ana i tēnei ka herea ki ngā panonitanga o te tohatoha taumahatanga. Kei te āhua 9 e whakaaturia ana te toronga o tētahi rākau taha-kotahi, kei te āhua 10 o tētahi rākau wāhanga-rua me 4 he papa poutū kotahi, ā, kotahi te kanohi i waenganui i ngā kokonga rino.
Wh. 9
Fig. 10
Te tūhono: Mō ngā tūhono o ngā tokotoko tō, e mau pū ana ngā hononga ōrite ki ērā mō te toronga. Kua whakaaturia e ngā whakamātau te tino painga o te whakauru tō taurite. Ki te tūhono taha kotahi, ka puta he piko nui i te ahunga roa me te ahunga whānui (whaka. 11). Ahakoa ngā pēhanga piko tāpiri nui, ka taea te whakamahi tata katoa i ngā tokotoko L me C kua tūhonotia taha kotahi. Ka heke pea te kaha kawe o tētahi tūhono ki te haurua mēnā kāore i mahia he tikanga hei taurite i ngā meneti piko tāpiri.
Whak. 11
Mō te uhi i ngā pito hono me kaua e tango ngā pepa kōpuku, engari me whakarite mō aua mea he here motuhake. Ka māmā ake te hono ki te pepa kōpuku ina taka te nuinga o te wāhanga whakawhiti o te rākau ki te rererangi o te pepa kōpuku.
Āhua 12 - Ngā hononga me te kore hononga koki tautoko
Tokotoko pēhia
Mō te toronga me te hono o ngā rākau pēhia e whai mana ana ngā mātāpono ōrite ki ērā mō ngā rākau tō, ā, ki ēnei anō ka whakawhitia te kaha katoa mā ngā riveti me ngā here, arā, e ai ki te mata katoa F o te rākau ka whakaritea te Fpodvezica me te Fs, ā, ko Fl hoki. I te nuinga o te wā kāore ngā mata o ngā toronga e taurite-kotahitia. I roto i ngā hanganga rino o ngā whare, mō ngā pou e haere ana mā ngā papa maha, e utaina ana mō te pēhanga anake, ka whakamahia te āhei ki te haere mā te iti ake o te uhi o ngā toronga. Kua pau te kaha kawe o ngā rākau pēhia, mēnā kāore i mua ka puta ngā āhuatanga koretau, ā, tōmuri rawa atu ko te taenga ki te rohe rerenga, nā te mea ka puta i reira ngā huringa nui, ā, ka kōpiko taha te rākau. Kāore he pānga e taea te kite atu o ngā rua kua whakakīa ki ngā riveti ki runga i te whanonga o te rākau.
Te kaha ki te ngenge o ngā hononga rivet
Mō te kaha ngenge o ngā hononga kōpere, ko ngā tihi pēhanga ka puta i ngā rua te mea matua. Kua tino whakahekehia te kaha ngenge nā ngā rua anō. Ka whati ngā tokotoko he rua tūwhera ō rātou i ngā whakamātau ngenge i raro i te tō, i ngā tapahanga kua ngoikore, ā, ka tīmata te whati ngenge i ngā kapiti i te tapa o te rua, e toro haere tonu ana mā te tapahanga. Nō reira he tino hiranga ngā rua maheni. Kei te whakaatu te whaka. 13 i te kaha ngenge o ngā tokotoko papatahi i ngā akomanga rerekē (kei matau ko te akomanga maitai teitei ake). I ngā uta o mua nui ake σu ka kawea e ngā rauemi e rua ngā kaha ngenge σDz kei runga ake i te pae tuku. He ōrite tata te hōkai o te pēhanga mō ngā akomanga e rua.
Whakaahua 13 - Kaha ngenge σDz
Mō te utaina huri mō te tō me te pēhi o ngā hononga nākuia, ka whai tonu ngā whanaungatanga ōrite ki ērā mō ngā utaina kotahi anake te aronga. Me mōhio ko te whānui o te pēhanga i raro i te utaina huri he nui ake, tata ki te 1,5 wā (sl. 14), engari he nui ake te mōrea ki ngā rivet i raro i tēnei utaina i tērā i raro i te utaina kotahi anake te aronga.
Wh. 14 - Te kaha ngenge ki te tō o ngā hononga rivet