Analysis of Structural Changes in Cold-Formed Steel Profiles Caused by Production Technology

摘要

Because of different production technology, the calculation of cold-formed profiles significantly differs from that of hot-rolled profiles. Formation of various section shapes from the basic sheets induces changes in material mechanical properties, which manifest themselves through different yield point, ultimate tensile strength, modulus of elasticity and reduced elongation percentage. Yield stress distribution over the cross section also changes, the largest values are in the corners of the profile. This paper presents testing results obtained from tensile coupons taken from different regions within profiles and compression tests on complex stub columns. Results are shown on cumulative diagrams and compared with those obtained from the base strip coupons. Before testing, a detailed measurement of real geometric properties of profiles was performed to determine the initial geometric imperfections of samples. The obtained results represent important parameters in determining appropriate buckling curves of centrically compressed members made from cold-formed profiles.