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Nelinearna statika ˇ stapnih konstrukcija Geometrijske imperfekcije

Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

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Page 1: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

Nelinearna statika stapnih konstrukcija

Geometrijske imperfekcije

Page 2: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

M 1(x) + Hw 1(x) − V(x) = 0

w(x) = wimp(x) + wel(x)

wimp.

wel.

w

Page 3: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

M 1(x) + Hw 1(x) − V(x) = 0

∫ x

0

w(x) = wimp(x) + wel(x)

M(x) + Hw(x) −

∫ x

0

V(ξ) dξ = 0

Page 4: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

M 1(x) + Hw 1(x) − V(x) = 0

∫ x

0

w(x) = wimp(x) + wel(x)

M(x) + H[

wimp(x) + wel(x)]

∫ x

0

V(ξ) dξ = 0

Page 5: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

M 1(x) + Hw 1(x) − V(x) = 0

∫ x

0

w(x) = wimp(x) + wel(x)

M(x) + Hwel(x) = −Hwimp(x) +

∫ x

0

V(ξ) dξ

Page 6: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

M(x) + Hwel(x) = −Hwimp(x) +

∫ x

0

V(ξ) dξ

M(x) = −EIw2el(x)

−EIw2el(x) + Hwel(x) = −Hwimp(x) +

∫ x

0

V(ξ) dξ

Page 7: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

M(x) + Hwel(x) = −Hwimp(x) +

∫ x

0

V(ξ) dξ

M(x) = −EIw2el(x)

EIw2el(x) − Hwel(x) = Hwimp(x) −

∫ x

0

V(ξ) dξ

Page 8: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

EIw2el(x) − Hwel(x) = Hwimp(x) −

∫ x

0

V(ξ) dξ

Page 9: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

EIw2el(x) − Hwel(x) = Hwimp(x) −

∫ x

0

V(ξ) dξ

Page 10: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

EIw2el(x) − Hwel(x) = Hwimp(x)

w2el(x) −

H

EIwel(x) =

H

EIwimp(x)

Page 11: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

w2el(x) −

H

EIwel(x) =

H

EIwimp(x)

wel(x) = wel,h(x) + wel,p(x)

Page 12: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

w2el(x) −

H

EIwel(x) = 0

w2el(x) =

H

EIwel(x)

wel,h(x) = eµx

w2el,h(x) = µ2 eµx

Page 13: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

w2el(x) −

H

EIwel(x) = 0

H = −Pt , Pt ą 0

w2el(x) +

Pt

EIwel(x) = 0

h = ℓ

c|H|

EI= ℓ

cPt

EI

w2el(x) +

h2

ℓ2wel(x) = 0

Page 14: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

w2el(x) +

h2

ℓ2wel(x) = 0

wel,h(x) = eµx

w2el,h(x) = µ2 eµx

µ2 eµx +h2

ℓ2eµx = 0

Page 15: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

(

µ2 +h2

ℓ2

)

eµx = 0

eµx ą 0

µ2 +h2

ℓ2= 0, µ2 = −

h2

ℓ2

µ1,2 = ¯ ih

Page 16: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

wel.,h,1(x) = e−ixh{ℓ, e−ix = cos x − i sin x

wel.,h,1(x) = cos

(

h

ℓx

)

− i sin

(

h

ℓx

)

wel.,h,2(x) = eixh{ℓ, eix = cos x + i sin x

wel.,h,2(x) = cos

(

h

ℓx

)

+ i sin

(

h

ℓx

)

Page 17: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

wel.,h(x) = b1wel.,h,1(x) + b2wel.,h,2(x)

= b1

[

cos

(

h

ℓx

)

− i sin

(

h

ℓx

)]

+ b2

[

cos

(

h

ℓx

)

+ i sin

(

h

ℓx

)]

= (−i b1 + i b2) sin

(

h

ℓx

)

+ (b1 + b2) cos

(

h

ℓx

)

Page 18: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

wel.,h(x) = (−i b1 + i b2) sin

(

h

ℓx

)

+ (b1 + b2) cos

(

h

ℓx

)

a1 = −i b1 + i b2

a2 = b1 + b2

wel.,h(x) = a1 sin

(

h

ℓx

)

+ a2 cos

(

h

ℓx

)

Page 19: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

w2el(x) −

H

EIwel(x) = 0

H = Pv , Pv ą 0

w2el(x) −

Pv

EIwel(x) = 0

h = ℓ

c|H|

EI= ℓ

cPv

EI

w2el(x) −

h2

ℓ2wel(x) = 0

Page 20: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

w2el(x) −

h2

ℓ2wel(x) = 0

wel,h(x) = eµx

w2el,h(x) = µ2 eµx

µ2 eµx −h2

ℓ2eµx = 0

Page 21: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

(

µ2 −h2

ℓ2

)

eµx = 0

eµx ą 0

µ2 −h2

ℓ2= 0, µ2 =

h2

ℓ2

µ1,2 = ¯h

Page 22: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

wel.,h,1(x) = e−xh{ℓ, wel.,h,2(x) = exh{ℓ

wel.,h(x) = b1wel.,h,1(x) + b2wel.,h,2(x)

= b1 e−xh{ℓ + b2 e

xh{ℓ

sh (x) =ex − e−x

2, ch (x) =

ex + e−x

2

wel.,h(x) = a1 sh

(

h

ℓx

)

+ a2 ch

(

h

ℓx

)

Page 23: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

w2el(x) −

H

EIwel(x) =

H

EIwimp(x)

Page 24: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

wimp(x) = w0 (ax2 + bx + c) = w0 swimp(x)

Page 25: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

wimp(x) = w0 (ax2 + bx + c) = w0 swimp(x),

swimp(0) = 0 ⇒ c = 0

swimp(ℓ{2) = 1 :ℓ2

4a +

2b = 1

swimp(ℓ) = 0 : ℓ2 a + ℓ b = 0

}a = −

4

ℓ2

b =4

wimp(x) = w0

$’%4

ℓx −

4

ℓ2x2

,/-

Page 26: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

w2el(x) −

H

EIwel(x) =

H

EIwimp(x)

w2el(x) +

h2

ℓ2wel(x) = −

h2

ℓ2wimp(x)

Page 27: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

w2el(x) +

h2

ℓ2wel(x) = −

h2

ℓ2wimp(x)

wel,p(x) = c0 + c1 x + c2 x2, w2

el,p(x) = 2 c2

wimp(x) = w0

$’%4

ℓx −

4

ℓ2x2

,/-

2 c2 +h2

ℓ2

$%c0 + c1 x+ c2 x

2,- = −

h2

ℓ2w0

$’%4

ℓx −

4

ℓ2x2

,/-

Page 28: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

$’’%2 c2 +

h2

ℓ2c0

,//- +

$’’%h2

ℓ2c1 +

4w0 h2

ℓ3

,//-x

+

$’’%h2

ℓ2c2 −

4w0 h2

ℓ4

,//-x2 = 0

h2

ℓ2c2 −

4w0 h2

ℓ4= 0 ⇒ c2 =

4w0

ℓ2

h2

ℓ2c1 +

4w0 h2

ℓ3= 0 ⇒ c1 = −

4w0

2 c2 +h2

ℓ2c0 = 0 ⇒ c0 = −

8w0

h2

Page 29: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

wel,p(x) = w0

$’%−

8

h2−

4

ℓx +

4

ℓ2x2

,/- = −

8w0

h2− wimp(x)

wel(x) = wel,h(x) + wel,p(x)

= a1 sin

(

h

ℓx

)

+ a2 cos

(

h

ℓx

)

+ w0

$’%−

8

h2−

4

ℓx +

4

ℓ2x2

,/-

Page 30: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

slobodno oslonjena greda:

wel(0) = 0 & wel(ℓ) = 0

a2 −8w0

h2= 0

a1 sinh + a2 cosh −8w0

h2= 0

a2 =8w0

h2

a1 =8w0

h2

1− cosh

sinh

Page 31: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

wel(x) =8w0

h2tg

h

2sin

(

h

ℓx

)

+8w0

h2cos

(

h

ℓx

)

+ w0

$’%−

8

h2−

4

ℓx +

4

ℓ2x2

,/-

Page 32: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

w2el(x) −

H

EIwel(x) =

H

EIwimp(x)

w2el(x) −

h2

ℓ2wel(x) =

h2

ℓ2wimp(x)

Page 33: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

w2el(x) −

h2

ℓ2wel(x) =

h2

ℓ2wimp(x)

wel,p(x) = c0 + c1 x + c2 x2, w2

el,p(x) = 2 c2

wimp(x) = w0

$’%4

ℓx −

4

ℓ2x2

,/-

2 c2 −h2

ℓ2

$%c0 + c1 x+ c2 x

2,- =

h2

ℓ2w0

$’%4

ℓx −

4

ℓ2x2

,/-

Page 34: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

$’’%2 c2 −

h2

ℓ2c0

,//- +

$’’%−

h2

ℓ2c1 −

4w0 h2

ℓ3

,//-x

+

$’’%−

h2

ℓ2c2 +

4w0 h2

ℓ4

,//-x2 = 0

−h2

ℓ2c2 +

4w0 h2

ℓ4= 0 ⇒ c2 =

4w0

ℓ2

−h2

ℓ2c1 −

4w0 h2

ℓ3= 0 ⇒ c1 = −

4w0

2 c2 −h2

ℓ2c0 = 0 ⇒ c0 =

8w0

h2

Page 35: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

wel,p(x) = w0

$’% 8

h2−

4

ℓx +

4

ℓ2x2

,/- =

8w0

h2− wimp(x)

wel(x) = a1 sh

(

h

ℓx

)

+ a2 ch

(

h

ℓx

)

+ w0

$’% 8

h2−

4

ℓx +

4

ℓ2x2

,/-

Page 36: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

slobodno oslonjena greda:

wel(0) = 0 & wel(ℓ) = 0

a2 +8w0

h2= 0

a1 shh + a2 chh +8w0

h2= 0

a2 = −8w0

h2

a1 = −8w0

h2

1− chh

shh

Page 37: Nelinearna statika ˇstapnih konstrukcija · 2020. 11. 10. · w el.,h,1(x) = e −ixh{ℓ, e−ix = cosx − isinx w el.,h,1(x) = cos h ℓ x − isin h ℓ x w el.,h,2(x) = e ixh{ℓ,

wel(x) =8w0

h2th

h

2sh

(

h

ℓx

)

−8w0

h2ch

(

h

ℓx

)

+ w0

$’% 8

h2−

4

ℓx +

4

ℓ2x2

,/-