The experiment result shows that the method mentioned above can obviously restrain its main mode(i.e.the first order vibration mode) vibration,and can be applied to controlling vibration of the structure.

In the method, three dimensional FEM is used to compute the temperature field and thermal bending deformation of rotor, or a first order vibration mode distribution procedure is adopted to estimate the thermal bending deformation of rotor.

From the view point of mechanical resonance,the first order vibration mode are analyzed as the dynamic characteristics of the floater servo system without built model,and it provides some bases for the design of servo system and the optimization of frame.

Numerical results show that the intervals of the elastic modulus of the dam concrete and the rock basement could be reliably identified by using the first order vibration mode values at several fixed points in the dam.

In 1985 Roddcn et al considered the coupling of rigid motion and elastic vibration. But their mathematical model appears to be inconvenient in engineering design. In this paper. the authors present a simplified mathematical model,which allows the authors to study the effect of sensor position on stability of elastic vehicle.Appropriate sensor's position along longitudinal axis. Analyaing zero-pole distribution. the authors can obtain rather optimal sensor position. Taking SAM-1 missile as example,we calculate...

In 1985 Roddcn et al considered the coupling of rigid motion and elastic vibration. But their mathematical model appears to be inconvenient in engineering design. In this paper. the authors present a simplified mathematical model,which allows the authors to study the effect of sensor position on stability of elastic vehicle.Appropriate sensor's position along longitudinal axis. Analyaing zero-pole distribution. the authors can obtain rather optimal sensor position. Taking SAM-1 missile as example,we calculate the appropriate distance of sensor from nose to be 5.45m. This calculated position agrees fully with the actual distance found in SAM-1 missile.In general, the authors believe that the following design suggestions can be made:(1)Normal type of flight vehicle. The group of sensors should be placed behind valley of first order vibration mode and ahead of those of 2nd and 3rd order vibration modes. In the SAM-1 numerical example mentioned above, the distance of 5.45m from nose to sensor farees with this design suggestion.(2) canard type of night vehicle. The suggestion for normal type nceds to be reversed in the case of canard type, i.e., the group of sensors should be placed ahead of valley of first order vibration mode and behind those of 2nd and 3rd order vibration modes.(3) Rotory wing type of flight vehicle. When actuator position is ahead of c.g., of flight vehicle, the suggestion for normal typeof flight vehicle should be followed; when it is behind c.g., the suggestion for canard type should be followed.

In this paper, a numerical analysis method of rotor′s thermal deflection and its affection on vibration response is studied. In the method, three dimensional FEM is used to compute the temperature field and thermal bending deformation of rotor, or a first order vibration mode distribution procedure is adopted to estimate the thermal bending deformation of rotor. A transfer matrix method is also employed to compute thermal bending vibration response. The results obtained...

In this paper, a numerical analysis method of rotor′s thermal deflection and its affection on vibration response is studied. In the method, three dimensional FEM is used to compute the temperature field and thermal bending deformation of rotor, or a first order vibration mode distribution procedure is adopted to estimate the thermal bending deformation of rotor. A transfer matrix method is also employed to compute thermal bending vibration response. The results obtained from this paper fit well with theoretical and experimental ones. The numerical method presented here can be applied to the analyses of thermal deflection and its affection on vibration response of a real rotor.

Based on the coupled dynamic model for the spatial rotation and elastic vibration of a body, the aeroelastic stability of rockets in flight is studied by Laplace transform equations Under the consideration of a first order vibration mode, the static aeroelastic stability condition is obtained According to the Hurwitz discriminance of stability, the dynamic stability conditions are derived and the diagram of dynamic stability is determined The results are of great importance...

Based on the coupled dynamic model for the spatial rotation and elastic vibration of a body, the aeroelastic stability of rockets in flight is studied by Laplace transform equations Under the consideration of a first order vibration mode, the static aeroelastic stability condition is obtained According to the Hurwitz discriminance of stability, the dynamic stability conditions are derived and the diagram of dynamic stability is determined The results are of great importance to the design of projectiles or rockets having large L/D ratios