scope:

Under sponsorship of the American Institute of Steel Construction, test equipment has been developed in which various desired combinations of axial load and end moments may be applied to metal columns. Lengths of 8, 12, and 16 feet may be accommodated in the apparatus, which is designed to test steel columns up to an 8WF40 rolled section size. Axial load is applied by a universal testing machine of 800,000 pound capacity. The end moments are applied separately through lever arms with tension-comppression hydraulic jacks mounted in series with dynamometers which measure the thrust.

The behavior of test columns under load is determined by the use of four measuring techniques: (1) taut-wire and mirror deflection gages, (2) level bars, (3) SR-4 strain gages, and (4) whitewash. In addition, the momentproducing thrust is measured by aluminum tube dynamometers.

The test program is currently being sponsored by the Welding Research Council. Some of the test results obtained are presented to demonstrate the effectiveness of the apparatus.

The Objectives of the program are described, the principal one being todetermine the ultimate strength of steel columns under varying combinations of end moments and direct load.