' .
. ' .
'. ' ( ) , . ' (. 15.7, , ) :
σ = F/(δb) ≤ [σ]', (1)
σ ; F , ';
δ, b ' ;
[σ]' '.
' , , . [σ]' ' .
, , (Κσ ≤ 1,6). σ = 1
'. ' , (. . 15.2, , ), m = 0,7k.
', . 15.8, ,
τ = F/(0,7kl) ≤ [τ]', (2)
τ ; F , ';
k ; l ; [τ]' .
' l , ' (. 15.8, ) l = 2l, ' (. 15.8, ) l = 2l, ' (. 15 8, ) l = 0,28l + 1,5l.
l ' .
' 䳿 F (. 15.8, ) l = l1 + l2 (2). l1 l2 F, :
l1 = l2/(e1 + e2); l2 = l1/(1 + 2).
' , . 15.8, , F . (τF τT ):
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τF = F/(0.7kπd); τT = FT/A = 2T/(0,7kπd2); τ = √τF2 + τT2 ≤ [τ]'. (3)
FT = 2T/d, = 0.7kπd.
' Μ (. 15.9, ), ( . 15.9, a ).
, l . τM = M/Wp, Wp .
(l < b), , (. 159, ) 䳺 F = M/b. '
τM = M/(0,7klb) ≤ [τ]'. (4)
' (. 15.9, ), F1 = F cosα, F2 = F sinα, Μ = F2h.
, ( . 15.9, )
τmax = √ τF1 + τM)2 + τ2F2 ≤ [τ]', (5)
τF1 = F1/(2∙0,7kl); τF2 = F2/(2∙0,7kl); τM = M/(0,7klb).