The Research On Similitude Problem Of Structural Dynamic Models And Technology Of Structural Dynamic Tests

Model test (MT) is an age-old yet important technology in terms of the study on the responses of a structure as well as the regularities of its internal forces and deformations when the structure is subject to various external loads. Even in the context where the computer technology has developed dramatically, MT methods still play an important role in improving structure engineering. With advantages of being able to not only verity the validity and correctness of designing and calculating but also demonstrate directly the state of complex details under given forces, this method is especially indispensable to the study of those problems, for the solutions of which ideal mathematical models could not be constructed.Similitude theory is the premise of MT. By practicing model tests, the author of the dissertation advanced three basic requirements and some skills to keep the similarities between models and prototypes in testing dynamic models and their ruptures, pointing out that there exist differences in similitude requirements according to the different experimental aims, namely, dynamic characteristics, elastic vibration responses and rupture forms as well. Through MTs could be obtained deeper comprehension of and more information about dynamic features of a structure and its rupture activities. The dissertation produced some new concepts on dynamic model testing especially as to certain intricate similitude problems of civil engineering buildings.Selecting model testing materials for a large concrete structure is of great significance to the results of the experiment. This dissertation analyzed the features of low strengthen-emulation concrete materials including their proportions, dynamic natures, as well as field applications. The analysis indicated that simulation materials are perfect for simulating experiments on large-scale structures. The repeatability of the multiple group experiments could make it possible to eliminate some uncertain factors in the course of the experiment. Consequently, the credibility, of the experiment could be guaranteed.Solution of hydro-structures is usually based on researching both hydrodynamic equation and structure dynamic equation. The structure forms, experiment materials and working condition are so complex that we need many concepts such as seismology engineering, aseismic engineering to solve the previously mentioned problems. Water structure covers seashore and coast engineering, hydraulic engineering, harbor engineering, nuclear power engineering and bridge engineering etc. Up to now, we still have a long way to go to the target about aseismic theory of hydro-structure although quiet great progress on it being acquired. We have many difficulties in simulating the distribution and variation of internal parameters of hydro-structures. One of which is how to simulate infinite water area when the hydro-structure model experiment is tested. But now, the situation has been improved since the under water seismic simulating system was constructed successfully. Some hydro-cantilever structure model tests in both widen water and narrow area have been conducted. And the author of this dissertation has finished preliminary research work on the under water shaking table experiments. A long discussed issue in earthquakeengineering is the responding and failure mechanism of chimney structure in the case of earthquake happening. An important and available research method for studying high towering structure is to do model tests. Some topics, such as seismic responding as earthquake comes from vertical or horizontal directions or which direction plays the major role for controlling the rupture of structure, have been discussed by some scholars. But the studies of those topics are short of test-based verification. Some research items have been done by testing 45m and 180m chimney structure dynamic models. And some significant and important results have been obtained from these researching works. Potent and convincing references are found for doing theory research on this engineerin...