Aeroelastic analysis of bridges using FEM and moving grids

In the recent years flow around bridges are investigated using computer modeling. Selvamrn(1998), Selvam and Bosch (1999), Frandsen and McRobie (1999) used finite element procedures. Larsenrnand Walther (1997) used discrete vorticity procedure. The aeroelastic instability is a major criterion to bernchecked for long span bridges. If the wind speed experienced by a bridge is greater than the critical windrnspeed for flutter, then the bridge fails due to aeroelastic instability. Larsen and Walther (1997) computedrnthe critical velocity for flutter using discrete vortex method similar to wind tunnel procedures. In thisrnwork, the critical velocity for flutter will be calculated directly (free oscillation procedure) similar to thernapproaches reported by Selvam et al. (1998). It is expected that the computational time required torncompute the critical velocity using this approach may be much shorter than the traditional approach. Therncomputed critical flutter velocity of 69 m/s is in reasonable comparison with wind tunnel measurement.rnThe no flutter and flutter conditions are illustrated using the bridge response in time.