kuchlanishni 2.1-rasm, b ga k o 'ra q u yid ag ich a aniqlasa boMadi:
X x = - F + cr A = 0 , bundan
F (2 .2 )
b u ye rd a F - sterjenga ta ’ s ir e tu vch i b o ‘y la m a ku ch ;
A - ste rje n n in g k o ‘ ndalang kesim yu za si;
K u c h la n is h n in g oMchami SGS sistem asida kg /sm 2 y o k i k g /m m 2 X a lq a ro
oM chov b ir lik la r i sistem asi SI da asosiy b i r li k H /m 2 y o k i Pa (P a ska l) b ila n
ifo d a la n d i.
U s h b u k u c h la n is h , tashqi kuch F s in g a ri, ke sim yuzasiga t ik y o ‘ n a lg a n lig i
sab a b li
normal ku c h la n is h deb ataladi. P riz m a tik sterjen s iq ilis h g a ish la -
ganda ham n o rm a l k u ch la n ish ana shu fo rm u la o rq a li a n iq la n a d i,fa q a t isho-
rasi m a n fiy boMadi.
K o n s tru k s iy a elem entlarida vujudga ke la d ig a n k u c h la r va d e fo rm a tsiya
la r o ‘ zaro bogMiq m iq d o rla rd ir: kuch boMmasa - deform atsiya boM m aydi; de-
fo rm a ts iy a boMmasa - kuchlanish boM m aydi. Y u k ortgan sari e g ilis h n in g (de-
fo rm a ts iy a n in g ) o rtis h in i, y u k kamaygan sari e g ilis h n in g k a m a y is h in i 1678-
y ild a in g liz o lim i R obert G u k ta jrib a yoMi b ila n aniqlagan va o ‘ z in in g mash
h u r q o n u n in i yaratgan. G u k qonuniga m u v o fiq defo rm a tsiya kuchga to ‘ g ‘ ri
p ro p o rs io n a ld ir. C h o ‘ z ilis h va siq ilish d a bu qon u n q u yid ag ich a ifo d a lan a d i:
a =
Ее. (2 .3 )
A m m o b u p ro p o rs io n a llik n in g chegarasi bor. K u c h la n is h n in g q iy m a ti
o rta b o rib , m a ’ lu m nuqtaga yetganda p ro p o rs io n a llik b u z ila d i. A n a shu nuqta
proporsionallik chegarasi deb a ta lib , tu r li m a te ria lla r u ch u n ta jrib a yoM i
b ila n a n iq la n a d i.
(2 .3 ) fo rm u la ta rk ib ig a k iru v c h i E k o e ffits ie n ti b irin c h i tu r