Vol. 5, No. 2, pp. 151-163 (2009)
NUMERICAL ANALYSES OF COLD-FORMED THIN-WALLED
SECTIONS WITH CONSIDERATION OF IMPERFECTIONS DUE
TO THE PRODUCTION PROCESS
Albrecht Gehring 1 and Helmut Saal 2,*
1 Research assistant, Versuchsanstalt für Stahl, Holz und Steine, Universität Karlsruhe (TH), Germany
2 Professor, Versuchsanstalt für Stahl, Holz und Steine, Universität Karlsruhe (TH), Germany
*(Corresponding author: E-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.)
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ABSTRACT
The load bearing capacity of cold-formed thin-walled sections strongly depends on deviations from the nominal dimensions and the material properties. The former reduce the load bearing capacity. The latter enhance the load bearing capacity, because of work hardening during the manufacturing process. It is difficult to realistically account for both effects in a finite-element analysis of the load bearing capacity of thin-walled sections. Today, cost intensive testing is necessary, if a maximum utilization of the load bearing capacity is desired. The properties of a product can be determined during the product development process with a new simulation strategy, which covers the production process as well as the state of serviceability of a product. The roll forming process is simulated first followed by a non-linear ultimate limit state analysis. The combination of both analysis steps gives the possibility to determine the load bearing capacity realistically as deviations from the nominal value of dimensions and material properties are included in the analysis. The new analysis strategy is demonstrated for a U-section with respect to different aspects concerning work hardening and the load bearing capacity of a C-section. It is shown, that the new strategy leads to a realistic estimation of the load bearing capacity of thin gauged sections.
KEYWORDS
Numerical analyses, cold-formed sections, imperfections, work hardening, ultimate limit state.
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