144 Mechanics of Materials §6.3 Wab Free moment diagram Ma王 Fixing moment diagram t Total B.M.diagram -Wo2 b Fig.6.3. (径x"2xL）+w+aL=0 Wab M+M8=- L (1) Also the deflection of A relative to B is zero;therefore the moment of the B.M.diagram between A and B about A is zero. [且x"空xa]g+"兜x]e+)+(wL×号)+Mu×号)=o w+2w+"2+"2(+)-0 Wab. M4+2Ma=-L8[2a2+3ab+b2] (2) Subtracting (1), wab」 Ma=-"p[2a2+3ab+b2-L2] but L=a+b, Wab Ma=-[2a+3ab+b2-a2-2ab-b] Wab Wa'bL 3Ca>+ab]=- Wa2b =- L2 (6.7)144 Mechanics of Materials 46.3 .. L Fig. 6.3. Also the deflection of A relative to B is zero; therefore the moment of the B.M. diagram between A and B about A is zero. ... [~x~xa]~+[jxt wabxb I( a+- :) + ( +MALx- 4) + ( +MBLx- 't) =O Wab MA+2M~= - ---[2a2+3ab+b2] L3 Subtracting (l), Wab L3 M 8- - - -[2a2 + 3ab+ b2 - L2] but L=a+b, Wab L3 .. M B- [2a2 + 3ab + bZ - a2 - 2ab - b2] Wab Wa'bL [a +ab] = -___ L3 L3 = -__