Comparison of Tests of Purlins with and Without Cleats

The paper describes a series of tests on Z-section purlins lapped over three spans and subject to wind uplift loading. The purlins were not attached to the rafters by cleats. Sheeting was screw-fastened to the purlins and a range of bridging (bracing) members was used to prevent lateral deflection and twisting. The results of the tests are compared with earlier tests with the same configurations but including cleats at the supports

Tests of Continuous Purlins under Downwards Loading

The paper describes a test program on purlin-sheeting systems for which the sheeting was screw fastened to the purlins. The test program simulates downwards loading. Z-section purlins were tested in three span continuous lapped configurations. The test purlins were supported by a range of bridging (bracing) members ranging from no bracing to one brace per span. The test results are compared with the design values computed using the Australian Cold-Formed Steel Structures Standard (AS1538-1988). The Australian Standard design is based on a flexural-torsional buckling analysis which may include the restraint from attached sheeting