ransformed section of composite columns

huangyhg

transformed section of composite columns
i am looking for some literature on the analysis of round columns that are composed of various materials.  i looked at the aisc 13th edition (concrete-filled tubes/encased tubes), aci 318-63 thru aci 318-05 (reinforced-concrete columns for both working stress and ultimate design), and even a mechanics of materials book, but i cannot find any information on how to transform different materials of a round column for axial and flexural analysis purposes.  for a column with axial compression only, all of the methods i've encountered simply take the area of each individual component multiplied by their allowable/ultimate strength and sum them up, without regard to their varying modulii of elasticity.  for a column with flexural load only, literature on transforming a section beyond the simple rectangular sections are few and far between.  any help and insight on this would be greatly appreciated.
strengi - if you are just looking for a quick analysis technique, use the aisc 13th edition plastic distribution method where the axial capacity is determined per equation i2-13, then calculate the plastic moment capacity for the steel tube section alone(fyz) as allowed per i3.3(b), then use the axial/moment interaction equations of chapter c as permitted by i4.  i know this does not directly answer your question of transformed areas, however it is a valid technique.
do you have circular concrete column with a wide flange core? if so, look at treating the wide flange as reinforcing steel. or do you have a steel tube filled with concrete?
thank you all for your input.  however, the question is not relative to steel, concrete, or any other specific material, but simply to analysis of columns composed of materials with varying modulii of elasticity by the transformed section method.  i was only referring to aisc and aci to determine their methods of analysis.