<![CDATA[Aeroelastic testing of a sectional bridge model in a wind tunnel with scale 1:20 had been conducted. The model was tested to study the characterictis of aeroelastics dynamic, such as Vortex Induced Vibration (VIV) and flutter. Based on the testing, phenomenon soft flutter was found in the test. Soft flutter has different characteristics as classical or hard flutter. In hard flutter, there are obvious divergence point, which is the point of wind speed when the amplitude increases suddenly and might be catastrophic. In soft flutter phenomenon, the vibration amplitude increases gradually as increasing of wind speed. In this paper, the characteristics of soft flutter on a model will be described and the method to determine its critical flutter speed.Keywords: Aeroelastic, flutter, divergence, critical flutter speedAbstrakPengujian aeroelastika di terowongan angin pada model seksional jembatan dengan skala 1:20 dilakukan untuk mengetahui karakteristik aeroelastika dinamik, yaitu Vortex Induced Vibration (VIV) dan flutter. Berdasarkan hasil pengujian terlihat fenomena flutter yang terjadi adalah soft flutter. Fenomena soft flutter berbeda dengan classical flutter atau hard flutter, dimana pada hard flutter terdapat titik divergen yang jelas. Pada hard flutter titik divergen ditandai dengan naiknya amplitudo menjadi sangat besar secara tiba-tiba dan dapat mengakibatkan kerusakan yang fatal. Pada soft flutter amplitudo getaran akan meningkat secara bertahap dengan bertambahnya kecepatan angin. Makalah membahas karakteristik soft flutter yang terjadi dan metode untuk menentukan kecepatan kritis flutter.Kata kunci : Aeroelastika, flutter, divergen, kecepatan kritis flutter]]>
