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EA u = A p = - so lis h tirm a p o te n sia l e n e rg iy a esa cr" k l 2 E A 2 E и = a e (4 .1 9 ) (4 .2 0 ) 2 E 2 ga teng boMadi. E n d i h a jm iy k u c h la n is h h o la tid a e le m e n tla r uchun s o lis h tirm a p o te n s ia l e n ergiyani a niqlashga o ‘ ta m iz . B u n in g u ch u n q irra la m in g u z u n lig i 1 ga te n g boMgan k u b ik a jra tib o la m iz ( 4 .1 1-rasm ). K u b ik n in g to m o n la ri (y o q la ri) bosh yu za ch a la r boM sin. B u yu za ch a la rg a bosh k u c h la n is h la r a ,, a 2 v a cr3 ta ’ s ir e ta d i, ham da k u b ik to m o n la r in in g d e fo rm a ts iy a la n is h i o q ib a tid a v u ju d g a ke ladigan k o ‘ c h is h la rd a ish b a ja ra d i. B u h o ld a k o ‘ c h is h la r bosh u z a y is h la r e . , e2, £3 ga teng boM adi, c h u n k i q irra la m in g u z u n lig i b irg a teng. jj - <~r i g l ! ° ~ ;g 2 , ^ 3 ° 3 2 S h u n d a y q ilib , (4 .2 0 ) ga asosan q u y id a g i ifo d a n i yo za o la m iz : ~ T ( 4 ’21 ) B o sh k u c h la n is h la r bajargan is h la r- aj n i b u ta x litd a q o ‘ s h is h im iz n in g b o is i shundan ib o ra tk i, bosh k u c h la n is h c , fa q a t s ) k o ‘ c h is h n in g v u ju d g a k e lis h - id a ish b a ja ra d i, cr, —>■ s , n in g , ct3 esa e } n in g v u ju d g a ke fish id a ish bajaradi. £,, £2, e 3 la m in g q iy m a tla r in i (4 .1 4 ) dan o lib , (4 .2 1 ) ga q o 'y s a k , de fo rm a ts iy a n in g t o ‘ liq s o lis h tirm a p o te n s ia l e n e rg iy a s i k e lib c h iq a d i: и = - - —Г o f + a l + a ] - l/u { a la 2 + a , a 3 + a 3a , ) 1 . (4 .2 2 ) 2E'~ J A s lid a bu e n e rg iya ik k i x il e n e rg iy a n in g y ig M n d is id a n ta s h k il to p a d i: a) k u b ik h a jm n in g o ‘ zgarishidan h o s il boM adigan e n e rg iy a - u v ; b ) k u b ik s h a k lin in g o ‘ zg arishidan (y a ’ n i k u b ik s h a k lid a n p a ra lle lp ip ip e d s h a k lig a o ‘ tis h id a n ) h o s il boM adigan e n e rg iy a - 4 / > - S o lis h tirm a p o te n sia l e n e rg iy a n in g h a r ik k a la ta s h k il e tu v c h is in i a n iq la y m iz . A w a l g i para g rfd a fa q a t h a jm o ‘ zgarganda h a r b ir q irra n in g n is b iy o ‘ z g a ris h i (4 .1 8 ) fo rm u la s id a n a n iq la n is h in i k o ‘ rib o ‘ tg a n e d ik . B u ye rd a _ a 1 + a1 + aJ_ , E 3 Va 3 ( 1 - 2 Ц) e k a n lig in i e s la tib o ‘ tam iz. B u n d a h a jm o ‘ zg arishidan h o sil boMgan e n e rg iya a l ( a , + a 2 + a 3y 3 2k \ U y o k i (4 .2 3 ) \ - 2 ц , \z hv = - ^ - ( ct , + c r , + o - , ) boM adi. B u m a ’ lu m boMgach, k u b n in g s h a kl o ‘ z g a ris h ig a s a r f boM adigan en e rg iy a n i q u y id a g i ayirm a d a n topsa boM adi: «ф = « - К = ^ [ ° f + а 1 + а 1 -2//(сг1сг;, +£7,<т3 +0-, •<73) ] - ^ |^ - [ с г 1 + СГ, +ст3]2. Ix c h a m la s h tiris h n a tija sid a , q u y id a g ig a ega boM am iz: иФ + a l + стз ~ f f iCT2 - о -, ' ~ е д ) • ( 4 -24) ЗЪ ^ O d d iy c h o ‘ z ilis h d e fo rm a ts iy a s id a , y a ’ n i cr2 = 0 , cr3 = 0 A. b o ‘ lganda, h a jm o ‘ z g a rish id a n h o s il boMgan s o lis h tirm a p o te n s ia l energiya ( 1 - 2 / / ) с г , - 6 E (1 - / / ) с т , (4 .2 5 ) shakl o ‘ z g a ris h i ene rg iya si * Ф = ' з Е ‘ (4 -2 6 ) boMadi. B in o b a rin , c h o ‘ z ilis h d a g i toM iq s o lis h tirm a e n e rg iya q u y id a g i y ig M n d ig a te n g boM adi: cr,2 г/ = w,. + ud, = —- . 1 ф 2 E 4.9. M ustahkamlik nazariyalari M u h a n d is lik h is o b in in g eng m u h im v a z ifa s i k u c h la r ta ’ s irid a boMgan e le m e n tn in g m u s ta h k a m lig ig a baho b erishdan ib o ra t. B u bo ra d a m a te ria lla r q a rs h ilig id a b ir necha m u s ta h k a m lik n a z a riy a la ri is h la b c h iq ilg a n . S hular- n in g a y rim la ri b ila n ta n is h ib ch iq a m iz . M ustahkam likning birinchi nazariyasi. B u n a za riya g a k o ‘ ra jis m n in g m u s ta h k a m lig ig a ta ’ s ir etadigan asosiy m iq d o r - eng k a tta n o rm a l k u c h la - n is h d ir, y a ’ n i n o rm a l kuchlanish orta b o rib , o ‘ z in in g x a v fli q iy m a ti a ° g a erish- ganda jis m (d e ta l) y e m irila d i, m ustahkam ligini y o ‘ qotadi. cr°n in g q iy m a ti o d d iy ch o ‘ z ilis h y o k i s iq ilis h g a sinash o rq a li ta jrib a yoM i b ila n a n iq la n a d i. M u ra k k a b k u c h la n is h h o la tid a m u s ta h k a m lik n i b u z ilis h s h a rti q u y id a g ic h a ifo d a la n a d i: o t - o ° - c h o ‘ z ilis h d a ; |сг31 = X a v fli k u c h la n is h ct ° n i z a x ira (zapas) k o e ffits ie n ti n ga boM ish o rq a li ru x s a t e tilg a n n o rm a l k u c h la n is h [c r ] a n iq la n a d i: H = - - n U h o ld a b ir o ‘ q li ku c h la n is h h o la ti u ch u n m u s ta h k a m lik sh a rti q u y id a g i k o ‘ rin is h n i o la d i: |cr3| < [ c r ] - s iq ilis h h o li uchun (4 .2 8 ) S hunday q ilib , m u s ta h k a m lik naza riya sid a uchta bosh k u c h la n is h (ст,, ст2, ct 3) lardan fa q a t b itta s i - eng ka tta si hisobga o lin a d i, q o lg a n ik k ita s i m u s ta h k a m lik k a ta ’ s ir e tm a y d i, deb qa ra la d i. T a jrib a la rn in g k o ‘ rs a tis h ic h a , b u n a za riya p la s tik m a te ria lla r u c h u n g in a q o n iq a rli n a tija la r b e ra d i, x o lo s . U shbu n a z a riy a X V I I asrda G a lile y to m o n id a n is h la b c h iq ilg a n . M ustahamlikning ikkinchi n azariyasi B u nazariyaga k o ‘ ra, m u sta h ka m l ik m ezoni s ifa tid a a b s o lu t m iq d o ri b o 'y ic h a eng katta c h iz iq li d e fo rm a t siya qabul q ilin a d i, y a ’ n i eng ka tta c h iz iq li d e fo rm a tsiya f max o ‘ z in in g x a v fli q iy m a ti £ ° ga e rish g a n d a e le m e n tn in g m u s ta h k a m lig ig a p u tu r y e ta d i (e le m e n t y e m irila d i), deb q a ra la d i. D e fo rm a ts iy a n in g x a v fli q iy m a ti ta jrib a y o ‘ li b ila n a n iq la n a d i. Shu m u lo h a z a la rd a n k e lib c h iq ib , e le m e n tn in g y e m irilis h s h a rtin i £ = £ ° (4 .2 9 ) m a x v 7 k o ‘ rin ish d a , m u s ta h k a m lik s h a rtin i esa (4 .3 0 ) k o ‘ rin is h d a ifo d a la s a boM adi. G u k n in g u m u m la s h g a n q o n u n id a n (4 .1 2 fo rm u la d a n ) fo y d a la n ib ham da eng katta n is b iy u z a y is h n i e, deb q a b u l q ilib , m u s ta h k a m lik sh a rti (4 .2 9 ) n i k u c h la n is h la r o rq a li ifo d a la y m iz : £ max = * i ^ [ с г . - М л + а -з )]. г I O d d iy c h o ‘ z ilis h u c h u n ru x s a t e tilg a n n o rm a l k u c h la n is h n i [ c r j deb qab u l q ils a k , eng k a tta n is b iy u z a y is h n in g ru xsa t e tilg a n q iy m a ti q u y id a g ich a ifo d a la n is h i m u m k in : И - Ы s max va [tr3] n in g q iy m a tla rin i m u s ta h k a m lik sh a rti (4 .3 0 ) ga q o ‘ ysak, y o k i cr, - / / ( c r , + c r 3) < [ c r ] (4 .3 1 ) k e lib c h iq a d i. Shunday q ilib , ik k in c h i n a za riya g a k o ‘ ra, o d d iy c h o ‘ z ilis h y o k i s iq ilis h uch u n b e lg ila n g a n ru x s a t e tilg a n n o rm a l k u c h la n is h b ila n b iro rta bo sh k u c h - la n is h emas, b a lk i ekvivalent (k e ltirilg a n ) k u c h la n is h deb n o m o lg a n , u la r- n in g m a jm u a si taqqoslanadi. B iz n in g h o ld a e k v iv a le n t ku ch la nish q u y id a g i k o ‘ rin is h g a ega: = с г 1 - M o - 2 + CT3) . (4 .3 2 ) T a jrib a la m in g k o ‘ rsatishicha m a zku r n a za riya p la s tik m a te ria lla r uchun ya x s h i n a tija b e rm a yd i. L e g irla n g a n c h o ‘ yan, o ‘ ta m u stahkam p o ‘ la t sin g a ri m o ‘ r t m a te ria lla r uchun aniq v a h a qiqatga y a q in n a tija la r b e ra d i. B u n a z a riy a n i M a rio t t a k lif etgan. M ustahkam likning uchinchi nazariyasi. B u n a za riya g a k o ‘ ra, m u s ta h k a m lik m e z o n i s ifa tid a eng katta u rin m a k u c h la n is h qabul q ilin a d i, y a ’ n i eng ka tta u rin m a ku ch la nish i m3x o ‘ z in in g x a v fli q iy m a ti x° ga erishganda elem ent m u sta h ka m lig i y o ‘ q o la di, deb qaraladi. U rin m a ku ch la n is h n in g x a v fli q iy m a ti t° o d d iy c h o ‘ z ilis h d a chegaraviy h o la td a n a n iq la n a d i. B u z ilis h sh a rti r m, , = r ° , (4 .3 3 ) m u s ta h k a m lik sharti k o ‘ rin is h g a ega. (4 .1 1 ) fo rm u la g a asosan W \ 0 ^ 0 г тах = 2 ( с7' ~ стз) va r = - c r b o M g a n lig i sa b a b li, b u z ilis h sharti (4 .3 3 ) va m u s ta h k a m lik sh a rti (4 .3 4 ) ni q u y id a g ic h a ifo d a la sa boMadi: cr, + cr, = c r° ; (4 .3 5 ) CTi - CT3 ^ M - (4-36) B u n d a e k v iv a le n t ku c h la n is h q u yid ag ich a ifo d a la n a d i: ^ e k v .I I l = CTI — a 3- (4 .37) Eng katta urinm a kuchlanishlar nazariyasi, ta jrib a la m in g ko ‘ rsatishicha, ay- niqsa pla stik m ateriallar uchun yaxshi natijalar beradi. Konstruksiya elementla- rin in g ishonchli oMchamlarini aniqlash im ko n in i beradi. B iro q bosh kuchlanishlar o , bilan ct 3 ning orasidagi qiymatga ega boMgan ct 2 ning hisobga olinm asligi, ushbu nazariyaning kam chiligi sanaladi. Bu nazariyani K u lo n ta k lif etgan. M ustahkam likning to ‘rtinchi nazariyasi. B u nazariyaga k o ‘ ra, m us ta h k a m lik m e z o n i s ifa tid a shakl o ;zgarishi p o te n s ia l e n e rg iya sin in g m iq d o ri q a b u l q ilin a d i. M a z k u r nazariyaga m u v o fiq , h a jm iy k u c h la n is h h o la tid a boMgan elem entda x a v fli h o la t shakl o ‘ zgarishiga o lib kela d ig a n s o lis h tir m a p o te n sia l energiya o ‘ z in in g c h e g a ra v iy q iy m a tig a erishganda vu ju d ga k e la d i. S o lis h tir m a p o te n s ia l e n e rg iy a n in g c h e g a ra v iy q iy m a ti o d d iy c h o ‘ z ilis h d a g i o q u v c h a n lik chegarasidagi q iy m a tg a te n g d ir. O q u v c h a n lik n i b o sh lan ish i sharti и ф = ( « ф)т (4 .3 8 ) M u s ta h k a m lik sharti »Ф ф , / , ] (4-39) S hakl o ‘ z g a rish i p o te n sia l e n e rg iy a s in i u m u m iy h o i uchun (4 .2 4 ) ga b in o a n q u yid a g ic h a yo zish m u m k in : 1 + '“ - [ o f + ct \ + cr I - (cr,cr2 + cr2cr3 + cr.cr,) ] . (4 .4 0 ) иФ=- 3E O d d iy c h o ‘ zilis h d a o q u v c h a n lik chegarasi uchun (c r, = с гж ; <т, = = 0 ) q u y id a g i ifodaga ega boM am iz; 1 + M 2 ( " * L “ 3E (1 4 ) va (1 5 ) n i (1 2 ) ga q o ‘ ysak, y o k i yla ] + 0 2 + <*l - (0-,0-2 + CT2CT3 + (7.С7,) = CT„; ( f f, -CJ2f + (ст, - СГ. ) 2 + ( cr, ) 2 (4.41) (4 .4 2 ) (4 .4 3 ) k e lib c h iq a d i. B u la rn i e ’ tib o rg a olsak, m u s ta h k a m lik sh a rtin i f a - ° г ) 2 + f a 2 ~ ) 2 + f a ; “ ^ Л - ~ = И n (4 .4 4 ) k o ‘ rin is h d a , to ‘ rtin c h i nazariya b o ‘ y ic h a e k v iv a le n t k u c h la n is h n i esa cr.., (cr, - c r , ) 2 + (o \, - cr. ) 2 + (ex. - cr, ) 2 (4 .4 5 ) ko ‘ rin is h d a ifodalasa boMadi. T a jrib a la r to ‘ rtin c h i nazariya c h o ‘ z ilis h va s iq ilis h g a b ir x il ish la yd ig a n p la s tik m a te ria lla r uchun t o ‘ g 'r i va aniq n a tija la r b e ris h in i k o ‘ rsatadi. S hunday q ilib , b iz m u s ta h k a m lik n in g t o ‘ rtta asosiy va k la s s ik n a za riya la ri b ila n qisqacha ta n ish ib c h iq d ik . A m m o m u s ta h k a m lik n a za riya la ri shu- с т т /J~7\ ’ ip n in g o ‘ zi b ila n tu g a m a y d i. B u m asala b o ‘ y ic h a M o r, Y u .l. Y a g n , G.S. P isa renko, A .A . Lebedev, Y a .B . F rid m a n k a b i ta n iq li o lim la r b a ra k a li qalam tebratganlar. 4.3-misol. Silindrik rezervuarning devoridan qirqib olingan elementning tomonlariga qiymati a ,=150 MPa, a , =75 MPa, ст }=0 bo'lgan kuchlar t a ’sir etadi. Rezervuar markasi St.3 bo'lgan kam uglerodli po 'latdan ishlangan. Cho ‘zilishga ruxsat etilgan kuchlanish (g)=160 MPa. Devorning mustahkamligi tekshirilsin (4.12-rasm). M a tre ria l p la s tik h o la td a b o M g a n lig i s a b a b li, h iso b is h la rin i t o ‘ r tin c h i y o k i u c h in c h i n a z a riy a la r b o ‘ y ic h a am alga o s h iris h maqsadga m u v o fiq . ст3 = 0 boMgani uchun to ‘ rtin c h i nazariya b o ‘y ic h a m u s ta h k a m lik sh a rti q u y id a g i k o ‘ rin ish g a ega boMadi: yl r, ci2 < [c r ]. cr, va cr, n in g b e rilg a n q iy m a tla rin i fo rm u la g a q o ‘ ysak, 4 .12-rasm. a eki.n . -J\502 + 1 5 2 - 1 5 0 - 7 5 = 1 2 9 ,9 Ш а ( [ а ] = \6 0 МПа k e lib ch iq a di. U c h in c h i nazariya b o ‘ yic h a m u sta h ka m lik sharti quyidagi k o ‘ rin ish g a ega; °<ыи =сг,_(Тз <[ y o k i а ,сЫП = 1 5 0 - 0 ( 1 6 0 М П а.. H is o b n a tija la rig a k o ‘ ra d e v o r m u s ta h k a m lig i ta ’ m inlangan. 4.4-misoL Egilishga ishlayotgan sterjenning xavfli nuqtasidan ajratib olingan elementning (4.13-rasm) tomonlariga quyidagi kuchlanishlar ta'sir etadi: a * =£7, T« = T> Mustahkamlikning to 'rtta nazariyasi bo 'yicha hisobiy (ekvivalent) kuchlanishlar aniqlansin. X a v fli nuqtadagi bosh k u c h la n is h la m i a n iq la y m iz : < 7 /7 = 0 , cr, = - j^ c r + \ / c r + 4 r 2 j ; cr, = — - л/сг2 + 4 T2 j . 1 1 1 J- / / / U h o ld a e k v iv a le n t k u c h la n is h la r v a m u s ta h k a m lik s h a rti q u y id a g i k o ‘ rin is h n i o la d i: a) b irin c h i nazariya b o ‘ y ic h a = CTi = + V o -2 + 4 T2) < [ c r ] ; b) ik k in c h i nazariya b o ‘ y ic h a ffeMi = c r, - ! л { а г + o \ ) = a + J o 2 +4т2 < [ c r ] . agar |i= 0 ,3 deb qab u l q ils a k , = 0 ,3 5 c r + 0 ,6 5 V o " + 4 r " ^ [ o -] ; d) u c h in c h i nazariya b o ‘y ic h a °еш и = ~ <*■> = V o -2 + 4 r 2 < [ o ’] ; e) to ‘rtin c h i nazariya b o 'y ic h a ( a , - < r 2) ' + ( o -2 - o -3) 2 + (c r 3 - o -,)2 = V c r2 + 3r* < [o -]. Shunday q ilib , m u s ta h k a m lik n in g t o ‘ rtta nazariyasi b o ‘ y ic h a e k v iv a le n t k u c h la n is h la m i to p d ik . Xulosa. B iz m a z k u r bobda n u q ta n in g m u ra kka b ku ch la nish va d e fo r m atsiya h o la tin i, q iy a k e s im la rd a h o s il b o ‘ la d ig a n k u c h la n is h la m i, bosh ku ch la n ish la r va bosh y u z a la m i, k u c h la n is h h o la ti tu rla rin i, k u c h la n is h ho - la tid a gi d e fo rm a ts iy a n in g p otensial e n e rg iya sin i k o ‘ rib o ‘ td ik , m u stahkam lik nazariyalari b ila n ta n is h d ik , M o r d o ira s in i q u ris h n i o ‘ rga n d ik. M is o lla r ye ch d ik. B ilim in g n i sin a b k o ‘ r 1. M urakkab k u ch lan ish h o latin in g qanday turlari bor? 2. Q iya yuzalardagi norm al va u rin m a k u ch lan ish lar qanday form ulalar bilan aniqlanadi? 3. U rinm a k u ch lan ish larin in g ju f tlik q o n u n i n im adan iborat? 4. H ajm iy v a tekis k u ch lan ish h o latid ag i sterjen lam in g deform atsiyalari q a n day topiladi? 5. Bosh y u zala r va bosh norm al k u ch lan ish lar nim a? 6 . Bosh y u zala rd a u rin m a k u ch lan ish larn in g qiym ati nim aga teng? 7. B osh y u zala rn in g y o ‘nalishlari qanday form uladan aniqlanadi? 8 . M or doirasi nim a? U ni ch izish tartibi qanday? 9. M or doirasidagi h ar bir n u q tan in g k o o rd in atasi nim ani bildiradi? 10. H ajm iy ku ch lan ish h o latid a ixtiyoriy qiya yuzadagi norm al va urinm a k u c h lanishlar qanday fo rm u lalar bilan to p ilad i? V B O B . S I O I S H M a v z u m a z m u n i. Mazkur bobda siljish deformatsiyasi haqida tushun- cha berilib, siljishda vujudga keladigan kuchlanish va deformatsiyalarni aniqlash usullari bayon etiladi. Parchin mix va payvand birikmalarini hisob- lashga doir misollar keltiriladi. 5.1. Siljishdagi kuchlanishlar. Siljishdagi Guk qonuni T e x n ik a a m a liy o tid a s iljis h d e form atsiyasi va q irq ilis h o q ib a tid a ishdan c h iq a d ig a n k o n s tru k s iy a e le m e n tla ri uchrab tu ra d i. B o lt y o k i p a rc h in m ix (за кл ё п ка ) y o rd a m id a ulangan b irik m a la r bunga m is o l b o ‘ la o la d i. P archin m ix li b irik m a la r o ‘ m in i k e y in g i davrlarda e le k tr payvand e g a lla y boshladi. B iro q b in o k o rlik d a , ke m a so zlik va sa m o ly o ts o z lik d a , k o ‘ p rik fe rm a la ri va re z e rv u a rla r q u rilis h id a p a rch in m ix h a li ham on o ‘ z m a v q e in i saqlab k e l- m oqda. S h unday ekan boMajak m uhandis k o n s tru k s iy a e le m e n tla rin i s iljis h - ga h iso b la sh u s u lla ri b ila n tanish b o ‘ lis h i lo z im . Ik k ita o ‘ zaro y a q in , am m o qaram a-qarshi y o ‘ nalgan kuch F katta q iy m a tg a ega boMsa, ste rje n q irq ila d i (5 .1 -ra s m ). S te rje n q ir q ilis h o ld id a n 5 .1 -rasm , b da k o ‘ rs a tilg a n id e k d e fo rm a ts iy a la n a d i. U s h b u d e fo rm a ts iy a siljish deb a ta la d i. S iljis h d a n a w a lg i abed t o ‘ g ‘ ri t o ‘ rtb u rc h a k siljis h d a n s o ‘ ng c 'd ’ p a ra lle lo g ra m m k o ‘ rin is h in i o la d i. cd ke s im i ab ke s im ig a nisba tan c c 1 m asofaga s iljiy d i (5.2-rasm ). B u m asofa ab so lut s iljis h deb ataladi. A b s o lu t s iljis h n in g q iy m a ti ik k ita q o ‘ shni ke sim ab ham da cd orasidagi m asofaga b o g ‘ liq . K e s im la r orasidagi m asofa qancha katta boMsa, absolut s iljis h ham shuncha ka tta boMadi. — > - Ч + С b i j Y i Y ' t f t J 1 1 / / / / : s s /s /s //////////// d m F • 1 Ғ n 5.3-rasm. O g‘ ish burchagi nisbiy siljish deb ataladi va quyidagiga nisbatdan aniqlanadi. c c 1 ( S .!) у burch a g i k ic h ik m iq d o r boMgani uchun b u rc h a k ta n g e n sin i b u rch a kn in g o ‘ ziga teng deb qabul q ilis h m u m k in . N is b iy s iljis h у n in g q iy m a ti ham , a b so lut s iljis h k a b i, ik k i q o ‘ shni ke sim orasidagi m asofa h ga b o g ‘ liq b o ‘ lib , ra d ia n la rd a o ‘ lchanadi. Q irq u v c h i k u c h F b ila n kuch la n ish ora sid a g i b o g ‘ la n is h n i a n iq la y m iz . B u n in g u c h u n k e s is h u s u lid a n fo y d a la n a m iz ; brus shak- lid a g i s te r je n n i m-n t e k is lig i b o 'y la b k e s ib (5 .3 -ra s m ) i k k i q is m g a a jra ta m iz . I k k in c h i q is m n in g b ir in c h i q is m g a b o M g a n t a ’ s ir in i ic h k i k u c h la r b ila n alm a sh tira m iz. B u k u c h la r s iljis h ja ra y o n id a v u ju d g a k e la d i gan u rin m a k u c h la n is h la r boMadi. A g a r ic h k i k u c h la r k e silg a n s irt b o ‘ y ich a b ir te kisd a tarqalgan deb faraz etsak, u rin m a k u c h la n is h la m i q u yid a g i fo r m ula d a n aniqlasa boMadi: T = l - <5-2) bu yerda A - ste rje n n in g k o 'n d a la n g ke sim yuzasi. T a jrib a la m in g k o 'rs a tis h ic h a , e la s tik lik chegarasida n is b iy s iljis h b ila n u rin m a ku ch la nish orasida c h iz iq li bogManish m a v ju d : y - x t G yoki T = G y , (5 .3 ) bu yerda G - p roporsionallik ko e ffitsie n ti boMib, siljishdagi e la s tik lik m o d u li y o k i ik kin ch i tu r e la stiklik m o d u li deb ataladi va M P a (y o k i Pa) bilan oMchanadi. у oMchamsiz son boMgani uchun G ning oMcham b irlig i ku ch la nish n iki bilan b ir x il. B a ’ zi m ateriallar uchun G ning q iym a ti 9 -ilo va d a ke ltirilg a n . (5 .3 )-fo rm u la s iljis h d a g i G u k q o n u n i deb ataladi. S iljis h d a g i absolut d e fo rm a tsiya n i a n iq la y m iz . B u d e fo m a ts iy a n in g q iy m a ti faqat u rin m a kuch la nish g a g in a emas, b a lk i e le m e n tn in g oM cham lariga ham bogM iqdir. U rin m a ku ch la nish v u ju d g a k e la d ig a n yu za n i A , p a ra lle l s irtla r orasidagi m asofani h, s iljitu v c h i k u c h n in g teng ta ’ s ir e tu v c h is in i Q = A t deb belgilasak, absolut s iljis h q u y id a g ic h a ifo d a la n a d i; л и r и Download 78.98 Kb. Do'stlaringiz bilan baham: 
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