Document Type

Conference Paper

Publication Date


Publication Title

Proceedings of the Annual Stability Conference Structural Stability Research Council


16 pp.

Conference Name

Annual Stability Conference Structural Stability Research Council, March 22-25, 2022, Denver, Colorado


Cold-formed steel C- and Z-shaped purlins in standing seam roof systems rely on the diaphragm action provided by the panels to restrain lateral movements and thus increase the load carrying capacity the purlins. The clip connection between the purlin and the panel has inherent and sometimes intentional flexibility designed to accommodate thermal deformations. The lateral deformation behavior of standing seam systems supported by Zees is highly nonlinear and this behavior is not well understood. The flexibility has major implications on the transfer of diaphragm forces throughout these systems and simplified models often grossly overpredict the demands on the diaphragm and the subsequent impacts on the purlin behavior. To investigate the behavior of standing seam diaphragm systems, shell finite element models are developed based on systems tested according to the AISI S908 Base Test. Initial models investigate separately flexibility in the panel versus flexibility in the purlin-to-panel clip connection to visualize the effects on the force transfer. Additional models were developed to investigate bilinear behavior of the panels and clips. These models are calibrated to AISI S907 Cantilever Test data and then compared to base test data. The variation of the diaphragm forces relative to the various diaphragm configurations is presented.


Copyright © Structural Stability Research Council. Reprinted with permission. All rights reserved.

Original Publication Citation

Seek, M. W. (2022) Exploring the effects of chip flexibility on the behavior of standing seam diaphragms to brace cold formed steel purlins [Conference Paper]. Annual Stability Conference Structural Stability Research Council, Denver, Colorado.


0000-0002-9137-8222 (Seek)