Small Scale Models for Steel Frameworks

The analysis and design of steel structures has become increasingly sophisticated and efficient in the last decade. For conventional structures, present methods of analysis can be employed with confidence with the proportioning of members based upon some prescribed criteria, such as building and bridge construction codes. When these methods can be employed, there can be no economic justification for a model study of a structure. Some aspects of both member and whole structure behavior, however, are still not well understood for these conventional structures and as new design criteria are developed for these situations, testing programs will be required. For unconventional structures, mathematical analyses that appropriately account for the complex geometries and behavior may not be available. It is in these areas, the development of design criteria for conventional structures and the study of unconventional structures, that model analysis can be useful. The use of experimental methods has already been demonstrated in tests carried out on full scale sections atLehigh University and other schools. These tests have effectively contributed to the incorporation of plastic design into building codes. On the other hand, full scale tests have a number of limitations. To date tests have been restricted to simple members and simple one, two or three story plane frames. While more complex structures, in many cases, would have masked the phenomenon under study there are situations where tests on larger or more complete structures would have been appropriate. Even in those situations where full scale study is feasible, the same total investment in small scale study would often permit a more comprehensive investigation. The purpose of this paper is to present the results of the first phase of a study aimed at establishing a reliable small scale ultimate strength modeling technique for wide-flange steel frameworks.