The Research On Comfort Degree Of A Museum’s Long-span Bi-directional Cantilever Floor

Since the21th Century, our country economy developed rapidly, people’sstandard of living improved constantly, the pursuit of the construction tends to belight and particular, that make the new type of structure in use and raise the level ofconstruction technology, with the applying of high strength and light weight materials.Due to the reduced stiffness and the increased span, the structure of modernengineering has a low natural frequency。At this moment,high level of vibrations canoccur in structure due to excitation from human activities such as walking andaerobics. In building structure, excessive vibrations are generally not a safety concernbut a cause of annoyance and discomfort. As the long-span floor structure developedquickly in China, it is important to do the research on human-induced vibrationproblem of long-span structure. Taking Qujin museum as the engineering background,the finite element model of floor is established by the finite element program MIDASand the research on human-induced vibration comfort of bidirectional cantileverlong-span structure is carried on. The work mainly includes following aspects:1) It summarized the appraisal system of vibration comfort, emphaticallyintroduced the method presented in ISO2631of how to calculate the comfort indices.On that basis, the annoyance rate model which based on psychological physicsmethod was introduced, and the annoyance rate method about museum floor is buildup, which make up for the deficiency that traditional appraisal system can only makequalitative judgment. The annoyance rate method realize the ualitative analysis offloor-vibration comfort standard.2) Commen pedestrian load model is recommend, and successive walking loadmodel is constructed as well.It analyse the human-induced vibration of cantileverbeam, After the analysis, a shortened form of spectrum method that can caculate themaximum acceleration of cantilever structure was brought forward.3) By using the program MIDAS, the finite element model of floor is establishedand three walking load which identified by the museum’s reasonable visit flow isapplied on. After that analysis, assessments about human-induced vibration comfort ismade by adopting the annoyance rate method of museum floor.