Wyznaczenie reakcji HA , VA , VB , HB
1.
Σ MA=0
-F∙1 + M + Q∙7,5 + Qx∙8 + Qy∙12 - VB∙10 + HB∙1 = 0
-10∙1 + 30 + 100∙7,5 + 80∙8 + 80∙12 - VB∙10 + HB∙1 = 0
-10 + 30 + 750 + 640 + 960 - VB∙10 + HB∙1 = 0
- VB∙10 + HB∙1 + 2370 = 0
HB = -2370 + 10VB
Σ MIIc = 0
Q∙3,5 + Qx∙2 + Qy∙8 - VB∙6 - HB∙5 = 0
100∙3,5 + 80∙2 + 80∙8 - VB∙6 - HB∙5 = 0
350 + 160 + 640 - VB∙6 - HB∙5 = 0
- VB∙6 - HB∙5 + 1150 = 0
6VB = 1150 - 5HB
6VB = 1150 - 5(-2370 + 10VB)
6VB = 1150 + 11850 - 50VB
56VB = 13000
VB = 232,1428 kN
HB = -2370 + 10(232,1428)
HB = -48,572 kN
2.
Σ MB=0
-HA + VA∙10 + M - Q∙2,5 + Qx∙7 + Qy∙2 = 0
-HA + VA∙10 + 30 - 100∙2,5 + 80∙7 + 80∙2 = 0
-HA + VA∙10 + 30 - 250 + 560 + 160 = 0
HA = 500 + 10VA
Σ MIc = 0
VA∙4 - HA∙6 + F∙5 + M = 0
VA∙4 - HA∙6 + 10∙5 + 30 = 0
VA∙4 - HA∙6 + 80 = 0
4VA = -80 + 6HA
4VA = -80 + 6(500 + 10VA)
4VA = -80 + 3000 + 60VA
-56 VA = 2920
VA = -52,1428 kN
HA = 500 + 10(-52,1428)
HA = 500 - 521,428
HA = -21,428 kN
Sprawdzenie:
ΣFx=0
HA - F + HB + Qx = 0
-21,428 - 10 - 48,572 + 80 = 0
0 = 0
ΣFy=0
VA - Qy + VB - Q = 0
-52,1428 - 100 + 232,1428 - 80 = 0
0 = 0
Obliczenie reakcji VC i HC w przegubie
ΣFIIy=0
VC - Q - Qy + VB = 0
VC - 100 - 80 + 232,1428 = 0
VC = -52,1428 kN
ΣFIIx=0
HC + HB + 80 = 0
HC - 48,572 + 80 = 0
HC = 31,428 kN