Jim LaBelle co-authored an article with Tanya Dolby of Kawneer, based on extensive screw pull-out testing by Kawneer. This type of connection, to resist outward wind pressure, is commonly used in aluminum framing for curtainwalls and skylights. In some but not all cases, mock-up tests are used to verify adequacy of these structural components. Hence there is a need for an analytical approach to predict pull-out strength.
The article compares predicted pull-out strengths, based on an unpublished older method, to test results. The finding is that the old method is significantly unconservative in many cases. Fortunately, there is now a new equation that compares well with those tests.
The article is available on lightmetalage.com by clicking here and in their April 2019 issue of their publication.