ENERGYMETHOD 3 General expressions of the strain energy Strain energy is independent of the order ofloading. Deformations due to mutually independent load may be summed up each other U N(x)1 d x t M(x) d x t M2(x) JL 2EA L2GlnJ2EⅠ Q2(x) dx L 2E4 als-> Deflection factor of shear For slender columns, the strain energy due to shearing forces may be neglected U= N(x x dx+ ndx t M2(x) L 2EAJL GIJL 2EI3、General expressions of the strain energy： Strain energy is independent of the order of loading. Deformations due to mutually independent load may be summed up each other. For slender columns，the strain energy due to shearing forces may be neglected. x EI M x x GI M x x EA N x U L L P n L d 2 ( ) d 2 ( ) d 2 ( ) 2 2 2    = + +  + L x EA Q x d 2 ( ) 2 S S → x EI M x x GI M x x EA N x U L L P n L d 2 ( ) d 2 ( ) d 2 ( ) 2 2 2    = + + Deflection factor of shear