Helical Spring Deflection The total strain energy for a helical spring consists of >Torsional component ·T=F*D/2=torque 、i=πdN >Shear component ·J=πd4/32=polar moment of inertia A=wire cross-sectional area Given by N=N.number of active coils T21 F21 U= 十 2GJ 2AG 。Or 4FDN FDN d'G d'GHelical Spring Deflection • The total strain energy for a helical spring consists of ¾Torsional component ¾Shear component • Given by A G lF GJ lT U 2 2 2 2 += • Or Gd DNF Gd NDF U 2 2 4 32 4 = + • T = F ∗D/2 = torque • l = πdN • J = π d 4/32 = polar moment of inertia • A = wire cross-sectional area • N = N a = number of active coils