In the current paper, the characteristic factor
β=[1 +0.904(σ_{b} / σ_{s}) ·
(1-σ_{s} / σ_{b})] is
extracted from the analytical solution of the bending moment for a rectangular
strainhardening beam first. Thereafter, the characteristic factor β is transplanted into the
previously proposed assessment of the critical buckling strain for rigid-perfectly plastic
bending pipe by analogy method, thus an extended expression of the critical buckling strain
for a pipe plastic bending including strain-hardening effect is developed,
$
\varepsilon_c=0.19 \frac{t}{r}\cdot \Big(1+\frac{1}{1.78r}\Big) \cdot [0.096+ 0.904/ (1-n)^2 ].
$
Moreover, available test data is employed to
check the suitability of the extended expression. The results show that the extended
expression is reasonable to reveal the effect of Hollomon type strain-hardening behavior on
the critical buckling strain of pipe plastic bending.
Keywords: plastic bending, buckling, critical strain, strain-hardening, pipe |
full paper (pdf, 1696 Kb)