Fisika Dasar II - spada.uns.ac.id
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Fisika Dasar II Benda Tegar dan Elastisitas (Bagian 3) S1 Teknik Sipil-Fakultas Teknik Tim Dosen
Transcript of Fisika Dasar II - spada.uns.ac.id
Fisika Dasar IIB e n d a Te g a r d a n
E l a s t i s i t a s( B a g i a n 3 )
S1 Teknik Sipil-Fakultas Teknik
Tim Dosen
Modulus Elastisitas
• Sifat elastis adalah sifat
bahan yang cenderung
kembali ke bentuk semua
setelah gaya yang bekerja
pada benda dihilangkan.
• Deformasi sisa
(residual displacement)
terjadi jika suatu benda
diberikan gaya melampaui
batas elastisnya.
0
konstan
Y=
L
L
F
A
Y
FA
LL
YAF L
L
F kx
YAk
L
=
=
= =
=
=
=
0
konstan
Y=
L
L
F
A
Y
FA
LL
YAF L
L
F kx
YAk
L
=
=
= =
=
=
=
0
konstan
Y=
L
L
F
A
Y
FA
LL
YAF L
L
F kx
YAk
L
=
=
= =
=
=
=
0
konstan
Y=
L
L
F
A
Y
FA
LL
YAF L
L
F kx
YAk
L
=
=
= =
=
=
=
0
konstan
Y=
L
L
F
A
Y
FA
LL
YAF L
L
F kx
YAk
L
=
=
= =
=
=
=
0
konstan
Y=
L
L
F
A
Y
FA
LL
YAF L
L
F kx
YAk
L
=
=
= =
=
=
=
0
konstan
Y=
L
L
F
A
Y
FA
LL
YAF L
L
F kx
YAk
L
=
=
= =
=
=
=
0 panjang awal batang; = perubahan panjang; regangan ( ); tegangan
gaya; = luas penampang; konstanta pegas; = deformasi aksial
L L strain
F A k x
= = =
= =
Contoh 11
WFWA A
Y Y Y YA
= = = =
0
konstan
Y=
L
L
F
A
Y
FA
LL
YAF L
L
F kx
YAk
L
=
=
= =
=
=
=
0
konstan
Y=
L
L
F
A
Y
FA
LL
YAF L
L
F kx
YAk
L
=
=
= =
=
=
=
0
konstan
Y=
L
L
F
A
Y
FA
LL
YAF L
L
F kx
YAk
L
=
=
= =
=
=
=
;L
L LL
= =
Contoh 11
Contoh 11
Modulus Geser
L L
L L
F
A
G
FAG
LL
GAF L
L
GAk
L
=
=
=
=
=
=
L L
L L
F
A
G
FAG
LL
GAF L
L
GAk
L
=
=
=
=
=
=
L L
L L
L L
F
A
G
FAG
LL
GAF L
L
GAk
L
=
=
=
=
=
=
L L
L L
F
A
G
FAG
LL
GAF L
L
GAk
L
=
=
=
=
=
=
L L
L L
F
A
G
FAG
LL
GAF L
L
GAk
L
=
=
=
=
=
=
Modulus Volum
1
o
o
V V P
V V PB
= − 1
o
o
V V P
V V PB
= −
Contoh 12
Susunan Kawat
1 2
1 2
1 2
1 1 1
ef
ef
ef
WL
k
L L L
W W W
k k k
k k k
=
= +
= +
= +
1 1
1
1
2 2
2
2
W k L
WL
k
W k L
WL
k
=
=
=
=
1 1
1
1
2 2
2
2
W k L
WL
k
W k L
WL
k
=
=
=
=
1 2
1 2
1 2
1 1 1
ef
ef
ef
WL
k
L L L
W W W
k k k
k k k
=
= +
= +
= +
Contoh 13
Susunan Kawat
1 1
2 2
1 2
1 2
1 2
ef
ef
ef
F k L
F k L
W k L
W F F
k L k L k L
k k k
=
=
=
= +
= +
= +
1 1
2 2
1 2
1 2
1 2
ef
ef
ef
F k L
F k L
W k L
W F F
k L k L k L
k k k
=
=
=
= +
= +
= +
1 1
2 2
1 2
1 2
1 2
ef
ef
ef
F k L
F k L
W k L
W F F
k L k L k L
k k k
=
=
=
= +
= +
= +
Contoh 15
Terima kasih….
