xx

∆ =

S

×l

E

×A

σ = F

A

= ε

× E = E × ∆

l

ε = ∆

l

- wzgl¦dna zmiana dªugoxci,

∂u

=ε × ∂x =⇒

´

0

l ∂u =ε ×

´

0

l ∂x

R =

−λ × ∆t × E × A

σ = R

A = -

λ

× ∆t × E

δ
r =const

τ max = rmax ×

M s

Is

rmax = d

2

Is = I0 = I − Iy = 2 × Iy
Θ =

M s

Is

×G

,

G - moduª xcinania,

M y = M × cosα, M z = M × sinα

σx=

My ×z

Iy

+

Mz ×y

Iz

Do rozci¡gania pr¦ta:
σx =

N

F

, εx =

σx

E

N

F

≤ R =⇒ N

R ≤

F, F =

π

×d2

4

∆i = εi × li- wydªuxenie przedziaªu,

∆i

li

= εi−wzgl¦dna zmiana dªugoxci, jak gdziex wyxej;]

Rozci¡ganie w pr¦cie → +,xciakanie→ −.