Special Truss Moment Frame Component Test 2 - 2C12x20.7

Special truss moment frame component test 2, made of double channels 2-C12x20.7, was tested under cyclic loading. The test setup is a representative of half of the chord in the special segment of the prototype special truss moment frame. To investigate the possibility of using the gusset plate to prevent lateral tosional buckling, 8-in. portion of the gusset plate was not welded to the specimen. This allowed the channels to slight along the gusset plate when being cyclically loaded. The plastic hinge formed roughly at the end of the weld as expected. Observation of flange local buckling started at about 1% story drift. Twisting of the specimen also started at this drift level, however; it is believed to be the result of eccentricity of the loading and inadequate out of plane restraint at the loading point. At 1.5% story drift, bulging of the webs were observed in addition to more apparent twisting. The test was terminated at 5.53% member drift while trying to achieve 2% story drift due to significant twisting and failing of the bracing.