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secCiÓn 8.5 Cargas combinadas 653<br />

b = 1.5 m<br />

W = 4.8 kN<br />

W<br />

h = 6.6 m<br />

h = 6.6 m<br />

T = 7.2 kN ⋅ m<br />

(a)<br />

(b)<br />

M<br />

A<br />

T<br />

C<br />

B<br />

V<br />

s A<br />

t 2<br />

t 1<br />

C t 1<br />

B<br />

A t 1<br />

(c)<br />

(d)<br />

y<br />

y<br />

A<br />

t xy = t 1<br />

B<br />

t xy = t 1 + t 2<br />

O<br />

x<br />

O<br />

x<br />

Figura 8.27 Solución <strong>de</strong>l ejemplo 8.6.<br />

(e)s y = s A<br />

(f)<br />

El par <strong>de</strong> torsión T produce esfuerzos cortantes t 1<br />

en los puntos A y B (figura<br />

8.27d). Po<strong>de</strong>mos calcular estos esfuerzos con la fórmula <strong>de</strong> la torsión:<br />

t 1<br />

T(d<br />

I P<br />

2/2)<br />

en don<strong>de</strong> I p<br />

es momento polar <strong>de</strong> inercia:<br />

p<br />

I P<br />

32 d 4 2<br />

d 4 1<br />

2I 126.92 10 6 m 4 continúa

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