| Description |
xviii, 173 leaves : illustrations, photographs ; 29 cm |
| Summary |
"This thesis focuses on two separate aspects of cold-formed steel connections, creating a standard for determining the strength of self-drilling screws, and determining how the connection strength varies with the number of screws in the connection, the screw spacing, and the pattern of the screws. Previously, no standard test method has existed for determining the strength of a self-drilling screw. Manufacturers have used their own test methods to determine the strength of their products, but no standard existed for which screws from different manufacturers could be reliably compared. A test standard has been developed based on American Society for Testing and Materials F606 for establishing bolt strengths. Tests have been performed to show the practicality of the proposed test standard. According to current design specifications, the screw pattern in a connection is ignored. This experimental study shows that the screw pattern has a minor effect, however it is negligible for purposes of design. The connection strength in current design specifications is based on single- and double-screw connection strength tests, with greater numbers of screws assumed to give a corresponding proportional increase in strength. This experimental study demonstrates that connection strength increases with additional screws in the connection, but at a rate slightly less than a multiple of the single- and double-screw strengths. Finally, these experiments reveal a decrease in connection strength with a decrease in center-to-center spacing of screws"--Abstract, leaf iii. |
|
