The Earthquake Engineering Online Archive

Inelastic behavior of beam-to-column subassemblages under repeated loading

Bertero, Vitelmo V.

UCB/EERC-68/02, Earthquake Engineering Research Center, University of California, Berkeley, 1968-04, 83 pages (530/B37/1968)

A review of some tests carried out in Japan on full-scale models of the beam-to-column connections in a building indicate the necessity of including the deformation that takes place in the panel zone in any rational method for predicting the behavior of subassemblages and, therefore, of a structure in general. Premature yielding or buckling of the panel zone can be avoided by stiffening this region, but the addition of these stiffeners is usually very expensive. Present methods of design are concerned only with the strength of the panel zone. Furthermore, these methods are usually based on results obtained in tests in which specimens have been loaded directly to collapse. This type of test does not represent the complete history of loading affecting the behavior of a multistory building that may be subjected to severe lateral actions of alternating directions. In these cases, a knowledge of the strength, stiffness, and ductility of the panel zone under repeated reversible loading is required before any rational assessment of structural behavior can be made. The study reported here forms part of a general investigation to obtain these data. The objective of the general investigation is to determine the inelastic behavior of beam-to-column subassemblages under repeated actions -- loading or imposed deformations. Two phases of work were planned. In the first, preliminary studies were done in order to plan a systematic program of tests that will form the second phase. Only the first phase is covered in this report. This first phase includes: (1) a review of current methods for reinforcing the panel zone; (2) analysis of available experimental data as well as analytical results with the objective of evaluating present practice and the most promising method for designing such panel zones against the effects of repeated loadings; (3) the development of a systematic and comprehensive program of testing scale models, full-scale specimens of panel zones, and whole subassemblages under repeated loading.

Available online: http://nisee.berkeley.edu/documents/EERC/EERC-68-02.pdf (5 MB)