A VD VD HD HD HA VA VB HB VC HC ∑ ∑

Transkrypt

A VD VD HD HD HA VA VB HB VC HC ∑ ∑
3U]\NáDG5DPDÄWUyMSU]HJXERZD´±SU]\SDGHN]áR*RQ\
:\]QDF]\üUHDNFMH
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podpory C wykorzystamy równania równowagi:
∑ M iDI = 0 i ∑ M iEIprawa = 0 .
i
i
0DMRQHSRVWDü
VC 2l + HC l –2ql l = 0
VC l + HC 2l –ql l/2 = 0.
= XNáDGX WHJR REOLF]\P\ *H
HC= - 1/3 ql i VC=7/6ql.
=QDN Ä´R]QDF]D *H ]ZURW UHDNFML +C
MHVWSU]HFLZQ\GR]DáR*RQHJR
: WHQ VSRVyE Z XNáDG]LH Z\MFLRZ\P X]\VNDOLP\ XNáDG VLá SU]HGVWDZLRQ\ QD SRQL*V]\P
rysunku .
E
D
HB
HA
VA
:
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SR]RVWDá\FK
1/3ql
VB
UHDNFML
7/6 ql
SRZWyU]\P\
WRN
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SRZDQLD
GOD
XNáDGX
„trójprzegubowego”. Do obliczenia reakcji pionowych wykorzystamy równania
∑ M iA = 0 i ∑ M iB = 0 .
i
i
3U]\MPXMRQHSRVWDü
VB 2l +7/6ql 3l –3ql 3/2l = 0 i -VA 2l +3ql 1/2l +7/6ql l –= 0,
VNGREOLF]DP\ZDUWRFLVB= 1/2 ql i VA=4/3ql.
'R REOLF]HQLD UHDNFML SR]LRP\FK PDM ZVSyOQ OLQL
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ZLHORNURWQ\P JG\* áF]\ ZL
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SU]HSURZDG]RQ\QDNLONDVSRVREyZSU]HGVWDZLRQ\FKQDU\VXQNX2GG]LDá\ZDQLDZND*G\P
]W\FKSU]\SDGNyZVLQQH
II
I
E
V1
HD
VD
HD
VD
A
D
C 1/3ql
D
HA
7/6ql
B
E
H1
V1
H1
B
C
A
4/3ql
E
D
H2
V2
C
V2
A
H2
HB
III
1/2ql
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'UXJL ] W\FK SRG]LDáyZ Z\NRU]\VWDP\ GR Z\]QDF]HQLD UHDNFML +A
. Równanie
i HC.
∑ M iDII = 0
i
SU]\MPLHSRVWDüTO
l + HA l + ql l/2
LVWG
2
HA = 5/6 ql.
7U]HFLSRG]LDáSR]ZROLZ\]QDF]\üUHDNFM
+B
Z równania
∑
III
M iD
.
= 0 Z\QLND*Hòql l- HB l = 0 i HB = ½ ql.
i
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UHDNFMLVSURZDG]RQHVGRZVSyOQHJRPLDQRZQLND
q
y
x
5/6 ql
8/6 ql
3
3/6 ql
2/6 ql
3/6 ql
7/6 ql