RMANERA
Structural
- Jan 13, 2010
- 14
Hi,
I want to estimate the resistant capacity of metallic tubes of circular section subjected to a longitudinal compression and external pressure calculated by the standard EN 1993-1-6, with non-linear analyzes (Geometrically and Materially non-linear Analysis with Imperfections - GMNIA).
I have seen some papers, assume the characteristic imperfection amplitude (Eq D.15) to represent a level of imperfection amplitude, with de shell in axial compression.
I have used “out-of-roundness tolerance” to represent the amplitude level of the imperfection, according to Table 8.1.
For exemple, if I have a cylindrical shell with: thickness t = 8,7 mm, radius R=865 mm, Q=40 (class A)
(i) the level of imperfection amplitude will be (t/Q)*(R/t)^0.5 according Eq D15, so 2.17 mm
(ii) the level of imperfection amplitude will be 0.0106 (class A) according Table 8.1.
The level of imperfection amplitude it´s very different.
What is the correct way to apply geometric imperfections by Eurocode?
I want to estimate the resistant capacity of metallic tubes of circular section subjected to a longitudinal compression and external pressure calculated by the standard EN 1993-1-6, with non-linear analyzes (Geometrically and Materially non-linear Analysis with Imperfections - GMNIA).
I have seen some papers, assume the characteristic imperfection amplitude (Eq D.15) to represent a level of imperfection amplitude, with de shell in axial compression.
I have used “out-of-roundness tolerance” to represent the amplitude level of the imperfection, according to Table 8.1.
For exemple, if I have a cylindrical shell with: thickness t = 8,7 mm, radius R=865 mm, Q=40 (class A)
(i) the level of imperfection amplitude will be (t/Q)*(R/t)^0.5 according Eq D15, so 2.17 mm
(ii) the level of imperfection amplitude will be 0.0106 (class A) according Table 8.1.
The level of imperfection amplitude it´s very different.
What is the correct way to apply geometric imperfections by Eurocode?