INSTYTUT POLITECHNICZNY
KIERUNEK : BUDOWNICTWO
WYTRZYMAŁOŚĆ MATERIAŁÓW
PROJEKT NR 5
Nazwisko Imię | Krzysztof Stachowiak |
---|---|
Rok/Grupa | II Gr. I sem. IV |
Rok akademicki | 2012/2013 r. |
Ocena |
$q_{B} = \frac{\left( 500 - 320 \right) \times 3,8}{6,6} + 320 = \mathbf{423,64\ kN/m}$
ΣPx = HA + HB = 0
HA = HB = 0
$\Sigma M_{B} = - R_{A} \times 2,8 - \left( 423,64 \times 2,8 \times 1,4 \right) - \left( \frac{\left( 500 - 423,64 \right)}{2} \times 2,8 \times 1,87 \right) + 320 \times 3,8 \times 1,9 + \left( \frac{\left( 423,64 - 320 \right)}{2} \times 3,8 \times 1,27 \right) = 0$
− RA × 2, 8 − 1660, 6688 − 199, 9105 + 2310, 4 + 250, 0833 = 0
$$\mathbf{\text{\ \ \ \ \ \ \ \ R}}_{\mathbf{A}}\mathbf{=}\frac{\mathbf{699,904}}{\mathbf{2,8}}\mathbf{= 249,9657\ kN}$$
$\Sigma M_{A} = - R_{B} \times 2,8 + 320 \times 6,6 \times 3,3 + \frac{\left( 500 - 320 \right)}{2} \times 6,6 \times 2,2 = 0$
−RB × 2, 8 + 6969, 6 + 1306, 8 = 0
$$\mathbf{\text{\ \ R}}_{\mathbf{B}}\mathbf{=}\frac{\mathbf{8276,4}}{\mathbf{2,8}}\mathbf{= 2955,8571\ kN}$$
SPRAWDZENIE:
ΣPy = 2112 + 594 + 249, 9657 − 2955, 8571 = 0, 1 błąd dop.
$$\sigma = \frac{N}{A} \leq R_{e} = > A = \frac{N}{R_{e}} = \frac{2955,86}{47,0} = \mathbf{62,89\ }\mathbf{\text{cm}}^{\mathbf{2}}$$
Przyjęto HEB 180
A=65,3 cm2
ix = 4, 57cm
iz = 7, 66cm
$$\lambda_{x} = \frac{l_{\text{ex}}}{i_{x}} = \frac{350}{4,57} = \mathbf{76,59}$$
$$\lambda_{z} = \frac{l_{\text{ez}}}{i_{z}} = \frac{700}{7,66} = \mathbf{91,38}$$
$$\lambda_{p} = \pi \times \sqrt{\frac{E}{R_{H}}} = \pi \times \frac{210000}{420} = \mathbf{70,248}$$
λmax = λz = 91, 38 > λp wyboczenie sprezyste
$$\sigma_{k} = \frac{\pi^{2} \times 210000}{{91,38}^{2}} = \mathbf{248,21\ MPa}$$
$$\frac{N}{A} \leq \sigma_{k}\ \ \ = > \ \frac{N}{A} = \frac{2955,86}{65,3} = \mathbf{45,27}\frac{\mathbf{\text{kN}}}{\mathbf{\text{cm}}^{\mathbf{2}}}\mathbf{= 452,7\ MPa}$$
452, 7 MPa>248, 21 MPa
Przyjęto HEB 200
A=78,1 cm2
ix = 5, 07cm
iz = 8, 54cm
$$\lambda_{x} = \frac{l_{\text{ex}}}{i_{x}} = \frac{350}{5,07} = \mathbf{69,03}$$
$$\lambda_{z} = \frac{l_{\text{ez}}}{i_{z}} = \frac{700}{8,54} = \mathbf{81,97}$$
$$\lambda_{p} = \pi \times \sqrt{\frac{E}{R_{H}}} = \pi \times \frac{210000}{420} = \mathbf{70,248}$$
λmax = λz = 81, 97 > λp wyboczenie sprezyste
$$\sigma_{k} = \frac{\pi^{2} \times 210000}{{81,97}^{2}} = \mathbf{308,467\ MPa}$$
$$\frac{N}{A} \leq \sigma_{k}\ \ \ = > \ \frac{N}{A} = \frac{2955,86}{78,1} = \mathbf{37,85}\frac{\mathbf{\text{kN}}}{\mathbf{\text{cm}}^{\mathbf{2}}}\mathbf{= 378,5\ MPa}$$
378, 5 MPa>308, 467 MPa
Przyjęto HEB 220
A= 91,0 cm2
ix = 5, 59cm
iz = 9, 43cm
$$\lambda_{x} = \frac{l_{\text{ex}}}{i_{x}} = \frac{350}{5,59} = \mathbf{62,61}$$
$$\lambda_{z} = \frac{l_{\text{ez}}}{i_{z}} = \frac{700}{9,43} = \mathbf{74,23}$$
$$\lambda_{p} = \pi \times \sqrt{\frac{E}{R_{H}}} = \pi \times \frac{210000}{420} = \mathbf{70,248}$$
λmax = λz = 74, 23 > λp wyboczenie sprezyste
$$\sigma_{k} = \frac{\pi^{2} \times 210000}{{74,23}^{2}} = \mathbf{376,15\ MPa}$$
$$\frac{N}{A} \leq \sigma_{k}\ \ \ = > \ \frac{N}{A} = \frac{2955,86}{91,0} = \mathbf{32,48}\frac{\mathbf{\text{kN}}}{\mathbf{\text{cm}}^{\mathbf{2}}}\mathbf{= 324,8\ MPa}$$
324, 8MPa<376, 15MPa
ZAPROJEKTOWANO PRZEKRÓJ SŁUPA WYKONANEGO Z DWUTEOWNIKA WALCOWANEGO HEB 220