The ambient temperature modulus of elasticity for cast iron in compression is 103.95 GPa (used in the numerical simulations, and according to [19]). The effective length factor is 1.0 for hinged ends and 0.5 for fixed ends. The column is assumed to have uniform temperature distribution in the and the average cross-section temperature is used. For axially restrained columns, the applied load is the maximum force in the column due to restrained thermal expansion. Figure 12 compares all the simulation results with calculation results using the Eurocode 3 Part 1-2 method (described above) for steel columns. In general, the analytical method gives conservative (safe) results. The results in Figure 12 also show that if the column load eccentricity does not exceed 0.2·D, using the EN 1993-1-2 design equation gives reasonably accurate and safe estimation of the limiting temperatures of cast iron column even if the effects of load eccentricity are not included. However, if the load eccentricity exceeds 0.2·D, it is no longer safe to assume the column to be under compression only. For stocky columns, the margin of safety is quite high. In fact, because the average temperature is used and the thicker part of the cross-section has lower temperatures, the column failure load may be even higher than the calculated plastic resistance of the cross-section with average uniform temperature. Nevertheless, it is considered not necessary to search for a more refined, and hence more accurate, method to calculate cast iron column resistance at elevated temperatures. Cast iron structures are no longer being constructed and there is not a
The ambient temperature modulus of elasticity for cast iron in compression is 103.95 GPa (used in the numerical simulations, and according to [19]). The effective length factor is 1.0 for hinged ends and 0.5 for fixed ends. The column is assumed to have uniform temperature distribution in the and the average cross-section temperature is used. For axially restrained columns, the applied load is the maximum force in the column due to restrained thermal expansion. Figure 12 compares all the simulation results with calculation results using the Eurocode 3 Part 1-2 method (described above) for steel columns. In general, the analytical method gives conservative (safe) results. The results in Figure 12 also show that if the column load eccentricity does not exceed 0.2·D, using the EN 1993-1-2 design equation gives reasonably accurate and safe estimation of the limiting temperatures of cast iron column even if the effects of load eccentricity are not included. However, if the load eccentricity exceeds 0.2·D, it is no longer safe to assume the column to be under compression only. For stocky columns, the margin of safety is quite high. In fact, because the average temperature is used and the thicker part of the cross-section has lower temperatures, the column failure load may be even higher than the calculated plastic resistance of the cross-section with average uniform temperature. Nevertheless, it is considered not necessary to search for a more refined, and hence more accurate, method to calculate cast iron column resistance at elevated temperatures. Cast iron structures are no longer being constructed and there is not a
with_chrys_columns.docx