Abstract

In the free vibration analysis, the result depends on exact autotyping of the composition feature of structure. The nearer essence the autotyping is, the more exact the result is. However that generates many elements and the processing on computer becomes slow. So converting deck and stringer into load on diaphragm will get the problem lessening many elements, the processing on computer becomes quicker, but the result of the arch rib internal force is unchangeable. However the stiffness of deck system is lower. The article will anlyse the free vibration of the concrete filled steel tube arch bridge in two cases: without considering affecting of deck system and considering affecting of deck system.