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Solutions for certain rectangular slabs continuous over flexible ...

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26 ILLINOIS ENGINEERING EXPERIMENT STATION<br />

1 (1 + A) P 7V<br />

M() | - log, coth --<br />

J x=./2 47r a<br />

-- Pv 1+ (1-p)1) v coth-- 2Vv csch--2vv<br />

2a 2a a a<br />

M ] (1 + p) P Vh<br />

=W - Irxr~ onih _ ~/O ~\<br />

J x=a/2 47r " a<br />

Pv P p- (1-)rv-- coth- 2iry<br />

csch<br />

2iy<br />

-- ,<br />

2a 2a a a<br />

M() = 0.<br />

xy I -a/2<br />

The resultant bending moment My in the slab <strong>over</strong> the beam<br />

becomes, when u = a/2 in (32),<br />

] Pv<br />

sinh -<br />

a<br />

sin --<br />

a<br />

M] = -_ - - -(36)<br />

i_0 a 2yrv<br />

cosh - + cosa<br />

2irx<br />

a<br />

7V<br />

rx<br />

Since the corrective twisting moment in the slab <strong>over</strong> the beam is<br />

zero, according to (35), the resultant twisting moment is given completely<br />

by the effect of a concentrated load on the infinitely long slab<br />

without the cross beam. The equation <strong>for</strong> the twisting moment in<br />

the slab <strong>over</strong> the beam is, there<strong>for</strong>e,<br />

cosh - cos -<br />

U ] = 1 (1- ) Pv a a<br />

M \ =M (0 \ =<br />

(37)<br />

,=0o J= 2a 2-v 2x (37)<br />

cosh - + cos -<br />

a<br />

a<br />

Westergaard* gives numerical values and curves obtained from an<br />

*H. M. Westergaard, Computation of Stresses in Bridge Slabs Due to Wheel Loads, Public Roads,<br />

V. 11, No. 1, March, 1930, p. 12-15. See Westergaard's Equation 75, Figures 12 and 14, and Table 5.

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