There was a factor of 2 missing in Eq. (36) in the original paper [1] and this error in Eq. (36) has propagated throughout the rest of the paper [1]. For the sake of brevity, only the affected equations are listed in the following:
Display Formula

(36)$U=2\xb7M2l2EI=\pi 2lEI$

Display Formula(37)$\pi 2lEI=EBlq$

Display Formula(38)$lq=\pi 2EIEB1l$

Display Formula(39)$lT=l+\pi 2EIEB1l\u22652l\xb7\pi 2EIEB1l=2\pi EIEB$

Display Formula(40)$lcr=4\pi EIEB=4\pi reqx=12.5664reqx$

Display Formula(44)$U1=2\xb7M12l12EI=EIl1\phi 12\u2003U2=2\xb7M22l22EI=EIl2\phi 22$

Display Formula(45)$EI(\phi 12l1+\phi 22l2)=EBlq$

Display Formula(46)$lq=EIEB(\phi 12l1+\phi 22l2)$

Display Formula$lT=l1+l2+lq=l1+sin\phi 11-sin\phi 1\phi 1-\pi 2\phi 1l1+EIEB(\phi 12l1+\phi 1(\phi 1-\pi 2)sin\phi 11-sin\phi 1l1)=l1(1+sin\phi 11-sin\phi 1\phi 1-\pi 2**\phi 1)+EIEB1l1(\phi 12+\phi 1(\phi 1-\pi 2)sin\phi 11-sin\phi 1)\u2003\u22652EIEB(1+sin\phi 11-sin\phi 1\phi 1-\pi 2\phi 1)(\phi 12+\phi 1(\phi 1-\pi 2)sin\phi 11-sin\phi 1)=2\phi 1EIEB(sin\phi 11-sin\phi 1+\phi 1-\pi 2\phi 1)(1-sin\phi 1sin\phi 1+\phi 1-\pi 2\phi 1)$

Display Formula(50)$lcr=4EIEBMin\pi 2<\phi <\pi h(\phi )$

Display Formula(53)$lcr=13.4487reqx$

Display Formula(58)$U=4k2EI[K(k)]2l[1-1k2K(k)-E(k)K(k)]$

Display Formula(59)$4k2EI[K(k)]2l[1-1k2K(k)-E(k)K(k)]=EBlq$

Display Formula(61)$cE=4k2[K(k)]2EIEB[1-1k2K(k)-E(k)K(k)]$

Display Formula(62)$lcr=8kK(k)req1-1k2K(k)-E(k)K(k)x$

Display Formula(63)$lcr=10.6038reqx$

Display Formula(70)$lcrL,f=1425.7A\xb0\u2003lcrU,f=2790.73A\xb0$

Display Formula(71)$lcrreq=4\pi x=12.5664x\u2003(a circle and a straight line)$

Display Formula(72)$lcrreq=13.4487x\u2003(two circles and a straight line)$

Display Formula(73)$lcrreq=10.6038x\u2003(an elliptic function and a straight line)$

Display Formula(74)$lcrL,e=2616.79A\xb0\u2003lcrU,e=3318.84A\xb0$