1. Trang chủ
  2. » Nông - Lâm - Ngư

Forest service 2010 wood handbook

8 7 0

Đang tải... (xem toàn văn)

THÔNG TIN TÀI LIỆU

Thông tin cơ bản

Định dạng
Số trang 8
Dung lượng 587,65 KB

Nội dung

8QLWHG6WDWHV 'HSDUWPHQWRI $JULFXOWXUH )RUHVW6HUYLFH )RUHVW 3URGXFWV /DERUDWRU\ *HQHUDO 7HFKQLFDO 5HSRUW )3/±*75± Wood Handbook Wood as an Engineering Material Centennial Edition &HQWHQQLDO(GLWLRQ Wood Handbook :RRGDVDQ(QJLQHHULQJ0DWHULDO Forest Products Laboratory • United States Department of Agriculture Forest Service • Madison, Wisconsin CHAPTER Structure and Function of Wood $OH[:LHGHQKRHIW%RWDQLVW Contents  %LRORJLFDO6WUXFWXUHRI:RRGDW'HFUHDVLQJ 6FDOHV± 7KH7UHH± 6RIWZRRGVDQG+DUGZRRGV± 6DSZRRGDQG+HDUWZRRG± $[LDODQG5DGLDO6\VWHPV± 3ODQHVRI6HFWLRQ± 9DVFXODU&DPELXP± *URZWK5LQJV± &HOOVLQ:RRG± &HOO:DOOV± 3LWV± 0LFURVFRSLF6WUXFWXUHRI6RIWZRRGVDQG +DUGZRRGV± 6RIWZRRGV± +DUGZRRGV± :RRG7HFKQRORJ\± 0RLVWXUH5HODWLRQV± 'HQVLW\± -XYHQLOH:RRGDQG5HDFWLRQ:RRG± $SSHDUDQFHRI:RRGDV6DZQ/XPEHU± &RORUDQG/XVWHU± *UDLQDQG7H[WXUH± 3ODLQVDZQDQG4XDUWHUVDZQ± 6ORSHRI*UDLQ6WUDLJKW'LDJRQDO 6SLUDODQG,QWHUORFNHG*UDLQ± .QRWV± 'HFRUDWLYH)HDWXUHV± :RRG,GHQWLILFDWLRQ± /LWHUDWXUH&LWHG± :RRGLVDFRPSOH[ELRORJLFDOVWUXFWXUHDFRPSRVLWHRI PDQ\FKHPLVWULHVDQGFHOOW\SHVDFWLQJWRJHWKHUWRVHUYHWKH QHHGVRIDOLYLQJSODQW$WWHPSWLQJWRXQGHUVWDQGZRRGLQ WKHFRQWH[WRIZRRGWHFKQRORJ\ZHKDYHRIWHQRYHUORRNHG WKHNH\DQGEDVLFIDFWWKDWZRRGHYROYHGRYHUWKHFRXUVHRI PLOOLRQVRI\HDUVWRVHUYHWKUHHPDLQIXQFWLRQVLQSODQWVʊ FRQGXFWLRQRIZDWHUIURPWKHURRWVWRWKHOHDYHVPHFKDQL FDOVXSSRUWRIWKHSODQWERG\DQGVWRUDJHRIELRFKHPLFDOV 7KHUHLVQRSURSHUW\RIZRRG²SK\VLFDOPHFKDQLFDOFKHP LFDOELRORJLFDORUWHFKQRORJLFDO²WKDWLVQRWIXQGDPHQWDOO\ GHULYHGIURPWKHIDFWWKDWZRRGLVIRUPHGWRPHHWWKHQHHGV RIWKHOLYLQJWUHH7RDFFRPSOLVKDQ\RIWKHVHIXQFWLRQV ZRRGPXVWKDYHFHOOVWKDWDUHGHVLJQHGDQGLQWHUFRQQHFWHG LQZD\VVXI¿FLHQWWRSHUIRUPWKHVHIXQFWLRQV7KHVHWKUHH IXQFWLRQVKDYHLQÀXHQFHGWKHHYROXWLRQRIDSSUR[LPDWHO\ GLIIHUHQWVSHFLHVRIZRRG\SODQWVHDFKZLWKXQLTXH SURSHUWLHVXVHVDQGFDSDELOLWLHVLQERWKSODQWDQGKXPDQ FRQWH[WV8QGHUVWDQGLQJWKHEDVLFUHTXLUHPHQWVGLFWDWHGE\ WKHVHWKUHHIXQFWLRQVDQGLGHQWLI\LQJWKHVWUXFWXUHVLQZRRG WKDWSHUIRUPWKHPDOORZLQVLJKWWRWKHUHDOPRIZRRGDVDQ HQJLQHHULQJPDWHULDO +RDGOH\ $VFLHQWLVWZKRXQ GHUVWDQGVWKHLQWHUUHODWLRQVKLSVEHWZHHQIRUPDQGIXQFWLRQ FDQSUHGLFWWKHXWLOLW\RIDVSHFL¿FZRRGLQDQHZFRQWH[W 7KHREMHFWLYHRIWKLVFKDSWHULVWRUHYLHZWKHEDVLFELRORJL FDOVWUXFWXUHRIZRRGDQGSURYLGHDEDVLVIRULQWHUSUHWLQJLWV SURSHUWLHVLQDQHQJLQHHULQJFRQWH[W%\XQGHUVWDQGLQJWKH IXQFWLRQRIZRRGLQWKHOLYLQJWUHHZHFDQEHWWHUXQGHUVWDQG WKHVWUHQJWKVDQGOLPLWDWLRQVLWSUHVHQWVDVDPDWHULDO 7KHFRPSRQHQWSDUWVRIZRRGPXVWEHGH¿QHGDQGGHOLP LWHGDWDYDULHW\RIVFDOHV7KHZRRGDQDWRPLFDOH[SHUWLVH QHFHVVDU\IRUDUHVHDUFKHUZKRLVXVLQJDVROLGZRRGEHDP LVGLIIHUHQWIURPWKDWQHFHVVDU\IRUDQHQJLQHHUGHVLJQLQJ DJOXHGODPLQDWHGEHDPZKLFKLQWXUQLVGLIIHUHQWIURP WKDWUHTXLUHGIRUPDNLQJDZRRG±UHVLQFRPSRVLWHZLWK ZRRGÀRXU'LIIHUHQFHVLQWKHNLQGVRINQRZOHGJHUHTXLUHG LQWKHVHWKUHHFDVHVDUHUHODWHGWRWKHVFDOHDWZKLFKRQH LQWHQGVWRLQWHUDFWZLWKZRRGDQGLQDOOWKUHHFDVHVWKH SURSHUWLHVRIWKHVHPDWHULDOVDUHGHULYHGIURPWKHELRORJLFDO QHHGVRIWKHOLYLQJWUHH)RUWKLVUHDVRQWKLVFKDSWHUH[SODLQV WKHVWUXFWXUHRIZRRGDWGHFUHDVLQJVFDOHVDQGLQZD\VWKDW GHPRQVWUDWHWKHELRORJLFDOUDWLRQDOHIRUDSODQWWRSURGXFH ZRRGZLWKVXFKIHDWXUHV7KLVEDFNJURXQGZLOOSHUPLWWKH UHDGHUWRXQGHUVWDQGWKHELRORJLFDOEDVHVIRUWKHSURSHUWLHV SUHVHQWHGLQVXEVHTXHQWFKDSWHUV $OWKRXJKVKUXEVDQGPDQ\YLQHVIRUPZRRGWKHUHPDLQGHU RIWKLVFKDSWHUZLOOIRFXVRQZRRGIURPWUHHVZKLFKDUHWKH 3–1 General Technical Report FPL±GTR±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± 2XWHUEDUNSURYLGHVPHFKDQLFDOSURWHFWLRQWRWKH VRIWHULQQHUEDUNDQGDOVRKHOSVWROLPLWHYDSRUDWLYHZDWHU ORVV,QQHUEDUNLVWKHWLVVXHWKURXJKZKLFKVXJDUV IRRG  SURGXFHGE\SKRWRV\QWKHVLVDUHWUDQVORFDWHGIURPWKHOHDYHV WRWKHURRWVRUJURZLQJSRUWLRQVRIWKHWUHH7KHYDVFXODU FDPELXPLVWKHOD\HUEHWZHHQWKHEDUNDQGWKHZRRGWKDW SURGXFHVERWKWKHVHWLVVXHVHDFK\HDU7KHVDSZRRGLVWKH DFWLYH³OLYLQJ´ZRRGWKDWFRQGXFWVWKHZDWHU RUVDS IURP WKHURRWVWRWKHOHDYHV,WKDVQRW\HWDFFXPXODWHGWKHRIWHQ FRORUHGFKHPLFDOVWKDWVHWDSDUWWKHQRQFRQGXFWLYHKHDUW ZRRGIRXQGDVDFRUHRIGDUNHUFRORUHGZRRGLQWKHPLGGOH RIPRVWWUHHV7KHSLWKDWWKHYHU\FHQWHURIWKHWUXQNLVWKH UHPQDQWRIWKHHDUO\JURZWKRIWKHWUXQNEHIRUHZRRGZDV IRUPHG 6RIWZRRGVDQG+DUGZRRGV 'HVSLWHZKDWRQHPLJKWWKLQNEDVHGRQWKHQDPHVQRWDOO VRIWZRRGVKDYHVRIWOLJKWZHLJKWZRRGQRUGRDOOKDUG ZRRGVKDYHKDUGKHDY\ZRRG7RGH¿QHWKHPERWDQLFDOO\ VRIWZRRGVDUHWKRVHZRRGVWKDWFRPHIURPJ\PQRVSHUPV PRVWO\FRQLIHUV DQGKDUGZRRGVDUHZRRGVWKDWFRPH IURPDQJLRVSHUPV À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–2 )LJXUH±0DFURVFRSLFYLHZRIDWUDQVYHUVHVHFWLRQ RID4XHUFXVDOEDWUXQN%HJLQQLQJDWWKHRXWVLGHRI WKHWUHHLVWKHRXWHUEDUN RE 1H[WLVWKHLQQHUEDUN LE DQGWKHQWKHYDVFXODUFDPELXP YF ZKLFKLVWRR QDUURZWRVHHDWWKLVPDJQL¿FDWLRQ,QWHULRUWRZDUGWKH YDVFXODUFDPELXPLVWKHVDSZRRGZKLFKLVHDVLO\GLI IHUHQWLDWHGIURPWKHKHDUWZRRGWKDWOLHVWRZDUGWKHLQ WHULRU$WWKHFHQWHURIWKHWUXQNLVWKHSLWK S ZKLFKLV EDUHO\GLVFHUQLEOHLQWKHFHQWHURIWKHKHDUWZRRG KDYHDFKDUDFWHULVWLFW\SHRIFHOOFDOOHGDYHVVHOHOHPHQW RU SRUH ZKHUHDVVRIWZRRGVODFNWKHVH )LJ±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¿QLWLRQLVWKDW VDSZRRGLVWKHEDQGRIOLJKWHUFRORUHGZRRGDGMDFHQWWRWKH EDUN+HDUWZRRGLVWKHGDUNHUFRORUHGZRRGIRXQGWRWKH LQWHULRURIWKHVDSZRRG )LJ±  ,QWKHOLYLQJWUHHVDSZRRGLVUHVSRQVLEOHQRWRQO\IRU FRQGXFWLRQRIVDSEXWDOVRIRUVWRUDJHDQGV\QWKHVLVRIELR FKHPLFDOV$QLPSRUWDQWVWRUDJHIXQFWLRQLVWKHORQJWHUP VWRUDJHRISKRWRV\QWKDWH&DUERQWKDWPXVWEHH[SHQGHGWR IRUPDQHZÀXVKRIOHDYHVRUQHHGOHVPXVWEHVWRUHGVRPH ZKHUHLQWKHWUHHDQGSDUHQFK\PDFHOOVRIWKHVDSZRRG DUHRIWHQZKHUHWKLVPDWHULDOLVVWRUHG7KHSULPDU\VWRUDJH IRUPVRISKRWRV\QWKDWHDUHVWDUFKDQGOLSLGV6WDUFKJUDLQV DUHVWRUHGLQWKHSDUHQFK\PDFHOOVDQGFDQEHHDVLO\VHHQ ZLWKDPLFURVFRSH7KHVWDUFKFRQWHQWRIVDSZRRGFDQKDYH LPSRUWDQWUDPL¿FDWLRQVLQWKHZRRGLQGXVWU\)RUH[DPSOH LQWKHWURSLFDOWUHHFHLED &HLEDSHQWDQGUD DQDEXQGDQFH Chapter Structure and Function of Wood )LJXUH±$WKHJHQHUDOIRUPRIDJHQHULFVRIWZRRGWUHH %WKHJHQHUDOIRUPRIDJHQHULFKDUGZRRGWUHH&WUDQV YHUVHVHFWLRQRI3VHXGRWVXJDPHQVLH]LLDW\SLFDOVRIW ZRRGWKHWKLUWHHQURXQGZKLWHVSDFHVDUHUHVLQFDQDOV 'WUDQVYHUVHVHFWLRQRI%HWXODDOOHJKHQLHQVLVDW\SLFDO KDUGZRRGWKHPDQ\ODUJHURXQGZKLWHVWUXFWXUHVDUH YHVVHOVRUSRUHVWKHFKDUDFWHULVWLFIHDWXUHRIDKDUGZRRG 6FDOHEDUV —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¶VV\VWHPRISURWHFWLQJLWVZRRG ([WUDFWLYHVDUHIRUPHGE\SDUHQFK\PDFHOOVDWWKHKHDUW ZRRG±VDSZRRGERXQGDU\DQGDUHWKHQH[XGHGWKURXJKSLWV LQWRDGMDFHQWFHOOV +LOOLV ,QWKLVZD\GHDGFHOOVFDQ EHFRPHRFFOXGHGRULQ¿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¿QLVKHGZLWKDZDWHUEDVHGSDLQWZLWKRXWDVWDLQEORFNHU H[WUDFWLYHVPD\EOHHGWKURXJKWKHSDLQWUXLQLQJWKHSURGXFW &KDS  $[LDODQG5DGLDO6\VWHPV 7KHGLVWLQFWLRQEHWZHHQVDSZRRGDQGKHDUWZRRGWKRXJK LPSRUWDQWLVDJURVVIHDWXUHWKDWLVRIWHQIDLUO\HDVLO\RE VHUYHG0RUHGHWDLOHGLQTXLU\LQWRWKHVWUXFWXUHRIZRRG VKRZVWKDWZRRGLVFRPSRVHGRIGLVFUHWHFHOOVFRQQHFWHG DQGLQWHUFRQQHFWHGLQDQLQWULFDWHDQGSUHGLFWDEOHIDVKLRQ WRIRUPDQLQWHJUDWHGV\VWHPWKDWLVFRQWLQXRXVIURPURRW WRWZLJ7KHFHOOVRIZRRGDUHW\SLFDOO\PDQ\WLPHVORQJHU WKDQZLGHDQGDUHVSHFL¿FDOO\RULHQWHGLQWZRVHSDUDWHV\V WHPVRIFHOOVWKHD[LDOV\VWHPDQGWKHUDGLDOV\VWHP&HOOV RIWKHD[LDOV\VWHPKDYHWKHLUORQJD[HVUXQQLQJSDUDOOHOWR WKHORQJD[LVRIWKHRUJDQ XSDQGGRZQWKHWUXQN &HOOVRI WKHUDGLDOV\VWHPDUHHORQJDWHGSHUSHQGLFXODUO\WRWKHORQJ D[LVRIWKHRUJDQDQGDUHRULHQWHGOLNHUDGLLLQDFLUFOHRU VSRNHVLQDELF\FOHZKHHOIURPWKHSLWKWRWKHEDUN,QWKH WUXQNRIDWUHHWKHD[LDOV\VWHPUXQVXSDQGGRZQIXQFWLRQV LQORQJGLVWDQFHZDWHUPRYHPHQWDQGSURYLGHVWKHEXON RIWKHPHFKDQLFDOVWUHQJWKRIWKHWUHH7KHUDGLDOV\VWHP UXQVLQDSLWKWREDUNGLUHFWLRQSURYLGHVODWHUDOWUDQVSRUW IRUELRFKHPLFDOVDQGLQPDQ\FDVHVSHUIRUPVDODUJHIUDF WLRQRIWKHVWRUDJHIXQFWLRQLQZRRG7KHVHWZRV\VWHPVDUH LQWHUSHQHWUDWLQJDQGLQWHUFRQQHFWHGDQGWKHLUSUHVHQFHLVD GH¿QLQJFKDUDFWHULVWLFRIZRRGDVDWLVVXH 3ODQHVRI6HFWLRQ $OWKRXJKZRRGFDQEHFXWLQDQ\GLUHFWLRQIRUH[DPLQDWLRQ WKHRUJDQL]DWLRQDQGLQWHUUHODWLRQVKLSEHWZHHQWKHD[LDODQG UDGLDOV\VWHPVJLYHULVHWRWKUHHPDLQSHUVSHFWLYHVIURP ZKLFKWKH\FDQEHYLHZHGWRJOHDQWKHPRVWLQIRUPDWLRQ 7KHVHWKUHHSHUVSHFWLYHVDUHWKHWUDQVYHUVHSODQHRIVHF WLRQ WKHFURVVVHFWLRQ WKHUDGLDOSODQHRIVHFWLRQDQGWKH 3–3 General Technical Report FPL±GTR±190 WDQJHQWLDOSODQHRIVHFWLRQ5DGLDODQGWDQJHQWLDOVHFWLRQV DUHUHIHUUHGWRDVORQJLWXGLQDOVHFWLRQVEHFDXVHWKH\H[WHQG SDUDOOHOWRWKHD[LDOV\VWHP DORQJWKHJUDLQ  7KHWUDQVYHUVHSODQHRIVHFWLRQLVWKHIDFHWKDWLVH[SRVHG ZKHQDWUHHLVFXWGRZQ/RRNLQJGRZQDWWKHVWXPSRQH VHHVWKHWUDQVYHUVHVHFWLRQ DVLQ)LJ±+ FXWWLQJDERDUG DFURVVWKHJUDLQH[SRVHVWKHWUDQVYHUVHVHFWLRQ7KHWUDQV YHUVHSODQHRIVHFWLRQSURYLGHVLQIRUPDWLRQDERXWIHDWXUHV WKDWYDU\ERWKLQWKHSLWKWREDUNGLUHFWLRQ FDOOHGWKHUDGLDO GLUHFWLRQ DQGDOVRWKRVHWKDWYDU\LQWKHFLUFXPIHUHQWLDOGL UHFWLRQ FDOOHGWKHWDQJHQWLDOGLUHFWLRQ ,WGRHVQRWSURYLGH LQIRUPDWLRQDERXWYDULDWLRQVXSDQGGRZQWKHWUXQN 7KHUDGLDOSODQHRIVHFWLRQUXQVLQDSLWKWREDUNGLUHFWLRQ )LJ±$WRS DQGLWLVSDUDOOHOWRWKHD[LDOV\VWHPVRLW SURYLGHVLQIRUPDWLRQDERXWORQJLWXGLQDOFKDQJHVLQWKHVWHP DQGIURPSLWKWREDUNDORQJWKHUDGLDOV\VWHP7RGHVFULEH LWJHRPHWULFDOO\LWLVSDUDOOHOWRWKHUDGLXVRIDF\OLQGHUDQG H[WHQGLQJXSDQGGRZQWKHOHQJWKRIWKHF\OLQGHU,QDSUDF WLFDOVHQVHLWLVWKHIDFHRUSODQHWKDWLVH[SRVHGZKHQDORJ LVVSOLWH[DFWO\IURPSLWKWREDUN,WGRHVQRWSURYLGHDQ\LQ IRUPDWLRQDERXWIHDWXUHVWKDWYDU\LQDWDQJHQWLDOGLUHFWLRQ 7KHWDQJHQWLDOSODQHLVDWDULJKWDQJOHWRWKHUDGLDOSODQH )LJ±$WRS *HRPHWULFDOO\LWLVSDUDOOHOWRDQ\WDQJHQW OLQHWKDWZRXOGWRXFKWKHF\OLQGHUDQGLWH[WHQGVDORQJWKH OHQJWKRIWKHF\OLQGHU2QHZD\LQZKLFKWKHWDQJHQWLDO SODQHZRXOGEHH[SRVHGLVLIWKHEDUNZHUHSHHOHGIURPD ORJWKHH[SRVHGIDFHLVWKHWDQJHQWLDOSODQH7KHWDQJHQWLDO SODQHRIVHFWLRQGRHVQRWSURYLGHDQ\LQIRUPDWLRQDERXW IHDWXUHVWKDWYDU\LQWKHUDGLDOGLUHFWLRQEXWLWGRHVSURYLGH LQIRUPDWLRQDERXWWKHWDQJHQWLDOGLPHQVLRQVRIIHDWXUHV $OOWKUHHSODQHVRIVHFWLRQDUHLPSRUWDQWWRWKHSURSHUREVHU YDWLRQRIZRRGDQGRQO\E\ORRNLQJDWHDFKFDQDKROLVWLF DQGDFFXUDWHXQGHUVWDQGLQJRIWKHWKUHHGLPHQVLRQDOVWUXF WXUHRIZRRGEHJOHDQHG7KHWKUHHSODQHVRIVHFWLRQDUH GHWHUPLQHGE\WKHVWUXFWXUHRIZRRGDQGWKHZD\LQZKLFK WKHFHOOVLQZRRGDUHDUUD\HG7KHWRSRORJ\RIZRRGDQGWKH GLVWULEXWLRQRIWKHFHOOVDUHDFFRPSOLVKHGE\DVSHFL¿FSDUW RIWKHWUHHVWHP 9DVFXODU&DPELXP 7KHD[LDODQGUDGLDOV\VWHPVDQGWKHLUFRPSRQHQWFHOOVDUH GHULYHGIURPDSDUWRIWKHWUHHFDOOHGWKHYDVFXODUFDPELXP 7KHYDVFXODUFDPELXPLVDWKLQOD\HURIFHOOVWKDWH[LVWV EHWZHHQWKHLQQHUEDUNDQGWKHZRRG )LJV±± WKDW SURGXFHVE\PHDQVRIPDQ\FHOOGLYLVLRQVZRRG RUVHF RQGDU\[\OHP WRWKHLQVLGHDQGEDUN RUVHFRQGDU\SKORHP  WRWKHRXWVLGHERWKRIZKLFKDUHYDVFXODUFRQGXFWLQJWLV VXHV /DUVRQ $VWKHYDVFXODUFDPELXPDGGVFHOOVWR WKHOD\HUVRIZRRGDQGEDUNDURXQGDWUHHWKHJLUWKRIWKH WUHHLQFUHDVHVDQGWKXVWKHWRWDOVXUIDFHDUHDRIWKHYDVFXODU FDPELXPLWVHOIPXVWLQFUHDVHDQGWKLVLVDFFRPSOLVKHGE\ FHOOGLYLVLRQDVZHOO 3–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±'( 6SULQJZRRGDQGVXP PHUZRRGZHUHWHUPVIRUPHUO\XVHGWRUHIHUWRHDUO\ZRRG DQGODWHZRRGUHVSHFWLYHO\EXWWKHLUXVHLVQRORQJHUUHFRP PHQGHG ,$:$  ,QWHPSHUDWHSRUWLRQVRIWKHZRUOGDQGDQ\ZKHUHHOVHZLWK GLVWLQFWUHJXODUVHDVRQDOLW\WUHHVIRUPWKHLUZRRGLQDQQXDO JURZWKLQFUHPHQWVWKDWLVDOOWKHZRRGSURGXFHGLQRQH JURZLQJVHDVRQLVRUJDQL]HGWRJHWKHULQWRDUHFRJQL]DEOH IXQFWLRQDOHQWLW\WKDWPDQ\VRXUFHVUHIHUWRDVDQQXDOULQJV 6XFKWHUPLQRORJ\UHÀ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± 7KHVHSDW WHUQVDSSHDULQERWKVRIWZRRGVDQGKDUGZRRGVEXWGLIIHULQ Chapter Structure and Function of Wood )LJXUH±$LOOXVWUDWLRQRIDFXWDZD\WUHHDWYDULRXVPDJQL¿FDWLRQVFRUUHVSRQG LQJURXJKO\ZLWKWKHLPDJHVWRLWVULJKWDWWKHWRSDWDQDSSUR[LPDWHPDJQL¿FDWLRQ RIỵDVRIWZRRGFHOODQGVHYHUDOKDUGZRRGFHOOVDUHLOOXVWUDWHGWRJLYHDVHQVH RIVFDOHEHWZHHQWKHWZRRQHWLHUORZHUDWDQDSSUR[LPDWHPDJQL¿FDWLRQRIỵLV DVLQJOHJURZWKULQJRIDVRIWZRRG OHIW DQGDKDUGZRRG ULJKW DQGDQLQGLFDWLRQRI WKHUDGLDODQGWDQJHQWLDOSODQHVWKHQH[WWLHUDWDSSUR[LPDWHO\ỵPDJQL¿FDWLRQLO OXVWUDWHVPDQ\JURZWKULQJVWRJHWKHUDQGKRZRQHPLJKWSURGXFHDVWUDLJKWJUDLQHG UDWKHUWKDQDGLDJRQDOJUDLQHGERDUGWKHORZHVWWLHULQFOXGHVDQLOOXVWUDWLRQRIWKH UHODWLYHSRVLWLRQRIMXYHQLOHDQGPDWXUHZRRGLQWKHWUHHDWỵPDJQL¿FDWLRQ%&OLJKW PLFURVFRSLFYLHZVRIWKHOXPLQD / DQGFHOOZDOOV DUURZKHDGV RIDVRIWZRRG % DQG DKDUGZRRG & '(KDQGOHQVYLHZVRIJURZWKULQJVHDFKFRPSRVHGRIHDUO\ZRRG HZ DQGODWHZRRG OZ LQDVRIWZRRG ' DQGDKDUGZRRG ( )DVWUDLJKWJUDLQHG ERDUGQRWHWKDWWKHOLQHDORQJWKHHGJHRIWKHERDUGLVSDUDOOHOWRWKHOLQHDORQJWKH JUDLQRIWKHERDUG*DGLDJRQDOJUDLQHGERDUGQRWHWKDWWKHWZROLQHVDUHPDUNHGO\ QRWSDUDOOHOWKLVERDUGKDVDVORSHRIJUDLQRIDERXWLQ+WKHJURVVDQDWRP\RID WUHHWUXQNVKRZLQJEDUNVDSZRRGDQGKHDUWZRRG 3–5 General Technical Report FPL±GTR±190 OXPLQHGODWHZRRGFHOOV )LJ±% 2WKHUZRRGVXQGHUJR DQDEUXSWWUDQVLWLRQIURPHDUO\ZRRGWRODWHZRRGVXFKDV VRXWKHUQ\HOORZSLQH 3LQXV ODUFK /DUL[ 'RXJODV¿U 3VHXGRWVXJDPHQ]LHVLL EDOGF\SUHVV 7D[RGLXPGLVWLFXP  DQGUHGZRRG 6HTXRLDVHPSHUYLUHQV  )LJ±& %HFDXVH PRVWVRIWZRRGVDUHQDWLYHWRWKHQRUWKWHPSHUDWHUHJLRQV JURZWKULQJVDUHFOHDUO\HYLGHQW2QO\LQVSHFLHVVXFKDVDU DXFDULD $UDXFDULD DQGVRPHSRGRFDUSV 3RGRFDUSXV GRHV RQH¿QGQRWUDQVLWLRQZLWKLQWKHJURZWKULQJ )LJ±$  6RPHDXWKRUVUHSRUWWKLVVWDWHDVJURZWKULQJVEHLQJDEVHQW RURQO\EDUHO\HYLGHQW 3KLOOLSV.XNDFKND  )LJXUH±/LJKWPLFURVFRSLFYLHZRIWKHYDVFXODU FDPELXP7UDQVYHUVHVHFWLRQVKRZLQJYDVFXODUFDP ELXP YF DQGEDUN E LQ&URWRQPDFURERWKU\V7KH WLVVXHDERYHWKHYDVFXODUFDPELXPLVZRRG6FDOH EDU —P 3RURXVZRRGV RUKDUGZRRGVZRRGVZLWKYHVVHOV KDYHWZR PDLQW\SHVRIJURZWKULQJVDQGRQHLQWHUPHGLDWHIRUP,Q GLIIXVHSRURXVZRRGVYHVVHOVHLWKHUGRQRWPDUNHGO\GLIIHU LQVL]HDQGGLVWULEXWLRQIURPWKHHDUO\ZRRGWRWKHODWHZRRG RUWKHFKDQJHLQVL]HDQGGLVWULEXWLRQLVJUDGXDODQGQR FOHDUGLVWLQFWLRQEHWZHHQHDUO\ZRRGDQGODWHZRRGFDQEH IRXQG )LJ±' 0DSOH $FHU ELUFK %HWXOD DVSHQFRW WRQZRRG 3RSXOXV DQG\HOORZSRSODU /LULRGHQGURQWXOLS LIHUD DUHH[DPSOHVRIGLIIXVHSRURXVVSHFLHV 7KLVSDWWHUQLVLQFRQWUDVWWRULQJSRURXVZRRGVZKHUHLQWKH WUDQVLWLRQIURPHDUO\ZRRGWRODWHZRRGLVDEUXSWZLWKYHV VHOGLDPHWHUVGHFUHDVLQJVXEVWDQWLDOO\ RIWHQE\DQRUGHURU PDJQLWXGHRUPRUH WKLVFKDQJHLQYHVVHOVL]HLVRIWHQDF FRPSDQLHGE\DFKDQJHLQWKHSDWWHUQRIYHVVHOGLVWULEXWLRQ DVZHOO7KLVFUHDWHVDULQJSDWWHUQRIODUJHHDUO\ZRRGYHV VHOVDURXQGWKHLQQHUSRUWLRQRIWKHJURZWKLQFUHPHQWDQG WKHQGHQVHUPRUH¿EURXVWLVVXHLQWKHODWHZRRGDVLVIRXQG LQKDFNEHUU\ &HOWLVRFFLGHQWDOLV ZKLWHDVK )UD[LQXV DPHULFDQD VKDJEDUNKLFNRU\ &DU\DRYDWD DQGQRUWKHUQ UHGRDN 4XHUFXVUXEUD  )LJ±)  )LJXUH±7UDQVYHUVHVHFWLRQVRIZRRGVVKRZLQJW\SHV RIJURZWKULQJV$UURZVGHOLPLWJURZWKULQJVZKHQSUHV HQW$±&VRIWZRRGV$QRWUDQVLWLRQZLWKLQWKHJURZWK ULQJ JURZWKULQJDEVHQW LQ3RGRFDUSXVLPEULFDWD %JUDGXDOWUDQVLWLRQIURPHDUO\ZRRGWRODWHZRRGLQ3LFHD JODXFD&DEUXSWWUDQVLWLRQIURPHDUO\ZRRGWRODWHZRRG LQ3VHXGRWVXJDPHQVLH]LL'±)KDUGZRRGV'GLIIXVH SRURXVZRRG QRWUDQVLWLRQ LQ$FHUVDFFKDUXP(VHPL ULQJSRURXVZRRG JUDGXDOWUDQVLWLRQ LQ'LRVS\URVYLUJLQ LDQD)ULQJSRURXVZRRG DEUXSWWUDQVLWLRQ LQ)UD[LQXV DPHULFDQD6FDOHEDUV —P HDFKEHFDXVHRIWKHGLVWLQFWDQDWRPLFDOGLIIHUHQFHVEHWZHHQ WKHWZR 1RQSRURXVZRRGV RUVRIWZRRGVZRRGVZLWKRXWYHVVHOV  FDQH[KLELWDQ\RIWKHVHWKUHHJHQHUDOSDWWHUQV6RPH VRIWZRRGVVXFKDV:HVWHUQUHGFHGDU 7KXMDSOLFDWD QRUWK HUQZKLWHFHGDU 7KXMDRFFLGHQWDOLV DQGVSHFLHVRIVSUXFH 3LFHD DQGWUXH¿U $ELHV KDYHJURZWKLQFUHPHQWVWKDW XQGHUJRDJUDGXDOWUDQVLWLRQIURPWKHWKLQZDOOHGZLGH OXPLQHGHDUO\ZRRGFHOOVWRWKHWKLFNHUZDOOHGQDUURZHU 3–6 6RPHWLPHVWKHYHVVHOVL]HDQGGLVWULEXWLRQSDWWHUQIDOOVPRUH RUOHVVEHWZHHQWKHVHWZRGH¿QLWLRQVDQGWKLVFRQGLWLRQLV UHIHUUHGWRDVVHPLULQJSRURXV )LJ±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ood Handbook :RRGDVDQ(QJLQHHULQJ0DWHULDO Forest Products Laboratory • United States Department of Agriculture Forest Service • Madison, Wisconsin CHAPTER Structure and Function of Wood. .. LPSRUWDQWUDPL¿FDWLRQVLQWKHZRRGLQGXVWU)RUH[DPSOH LQWKHWURSLFDOWUHHFHLED &HLEDSHQWDQGUD DQDEXQGDQFH Chapter Structure and Function of Wood )LJXUH±$WKHJHQHUDOIRUPRIDJHQHULFVRIWZRRGWUHH %WKHJHQHUDOIRUPRIDJHQHULFKDUGZRRGWUHH&WUDQV

Ngày đăng: 26/03/2021, 09:44

w