| The current Chinese Specification GB50018-2002 prescribes that the section thickness of main load carrying members in cold-formed structural shouldn't be less than 2mm for lacking of relative experimental data. So in order to verify the suitability of the specification GB50018-2002, it is necessary to carry out relative experimental and theoretical study on this subject.A total of 20 cold-formed lipped channel columns with section thickness of 1.0mm over a range of lengths from 600mm to 1800mm and with width to thickness ratio b/t=89, 140 under axial compression are tested. The test results show that it is conservative for the design of compression columns with thickness less than 2mm if according to current Chinese Specification GB50018-2002.Based on the tests, the finite element program ANSYS9.0 is applied to carry out the finite element nonlinear analysis of axial compressed channel columns with sectional thickness less than 2mm. The comparision of FEM results and test results shows that they are agree well with each other. Meanwhile, some parameters refer to section thickness, initial imperfections and so on are analysed by ANSYS. The FEM results show that the columns are sensitivity for initial imperfections .Based on the test and the finite element nonlinear analysis, load carrying capacity of columns are caculated by GB50018-2002, AISI 96 and Direct Strength Method. Then the results caculated by specifications are compared with the test results and the ANSYS results. The comparision show that the GB50018-2002 and Direct Strength Method could be used to calculate the load carrying capacity of compression members with section thickness less than 2mm. So the suggestion to the modifying of the current GB50018-2002 is put out in the paper. |
