Essentials in the theory of framed structures . Pig. 104. Mi is a maximum. For this reason we shall draw the influenceline for Mi as a load of i lb. moves across the span. When the load of i lb. is between Z4 and Li, the only forceacting on the left of the section is the left reaction Ro, and Mi= 50R0. As the load moves fromLi to Lo, Ro increases uniformlyfrom o to I- lb., and 5oi?o increasesuniformly from o to 50 f Hencethe line ON is the influence line forMi when the load of i lb. is betweenLi and L2. When the load of i lb. is betweenLo and Li, the only force acting onthe light of the
Essentials in the theory of framed structures . Pig. 104. Mi is a maximum. For this reason we shall draw the influenceline for Mi as a load of i lb. moves across the span. When the load of i lb. is between Z4 and Li, the only forceacting on the left of the section is the left reaction Ro, and Mi= 50R0. As the load moves fromLi to Lo, Ro increases uniformlyfrom o to I- lb., and 5oi?o increasesuniformly from o to 50 f Hencethe line ON is the influence line forMi when the load of i lb. is betweenLi and L2. When the load of i lb. is betweenLo and Li, the only force acting onthe light of the section is the right reaction Ri, and Mi =Soi?4. When the load is between Li and Li, there are twoforces acting on the right of the section—a floor beam load atLi and the truss reaction Ri; and the moment of these twoforces about Li is also Mi = ^oRi. As the load moves fromLo to Li, Ri increases uniformly from o to i lb.; and $oRiincreases uniformly from o to 50 Hence, the line QN. Pig. 105. 148 THEORY OF FRAMED STRUCTURES Chap. IV is the influence line for M2, when the load of i lb. is betweenLo and L2. Now it may be observed that the influence line ONQ for if 2is identical with the influence line which was drawn, when thecriterion for maximum bending moment at the center of theloo-ft. girder was required in Article 90. Hence, the criterionand position of an E-40 train are the same in each case. It wasfound in Article 90 that wheels 11, 12 and 13 at the center,
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectstructu, bookyear1922
