a suitable transmitting boundary for dynamic analysis of gravity dam – reservoir system utilizing ansys (technical note)

numerical analysis of the dam-reservoir systems including fluid-structure interaction, by finite element method has some complexities especially for the semi-infinite reservoirs. however, similar to the other fem program the ansys is included some difficulties in the modeling of the semi-infinite domains, such as the dam reservoirs. in this paper a new method is proposed to remedy this problem. for this, one of the existence elements of the mentioned program is used as an upstream boundary of the reservoir. this element which is able to absorb the waves rationally was named fluid129 in the ansys. it should be emphasized that to apply this element, some special conditions must be prepared which are presented in the article. after that, some practical results which obtained by the proposed method are compared with the exact responses which are attained by the other special purpose program, and they are reported in the literature. obviously this comparison could be clarified the ability of this new simple method for seismic analysis of dam-reservoir system.