|Statement||prepared by: Gary Davis, Ray Clough.|
|Series||NASA contractor report -- NASA CR-184100.|
|Contributions||Clough, Ray C., Rockwell International. Rocketdyne Division., George C. Marshall Space Flight Center.|
|The Physical Object|
The resultant stress distribution of the blade with the superposition of a tip friction force onto the centrifugal force is shown in Fig. 6. It can be seen that the peak stress location is transferred from the trailing to the leading edge corner when blade tip/casing rub strap impact takes by: To deal with these two problems, a novel method based on the vibration amplitudes of blade tip along axial direction is proposed to identify the effective detected position. The vibration stress of the whole blade then can be determined by linking the modified displacements to the mode shape information from finite element (FE) : Xiaojie Zhang, Yanrong Wang, Xianghua Jiang, Shimin Gao. Stress distribution analysis showed that when applying a contact force, the stress at the leading-edge root hole increases drastically. Therefore, experimental evidences as well as numerical simulations confirm that the crack occurred due to rubbing between the blade tip and the nearby wall. Experimental results obtained for an Inconel ® compressor blade rubbing bare-steel and treated casings at engine speed are described. Since a number of experiments were conducted to generate a broad database for tip rubs, the Rotor-Blade Rub database obtained using the unique experimental facility at the The Ohio State University Gas Turbine Laboratory.
As the forces applied on the wind turbine blade are irregular, the deformation and concentrated stress of the blade may vary with the load and excitation. And the lamination of composite materials is critical to blade design, it directly affects the performance and power of wind power plants. In this paper, the response characteristics of the wind turbine blade is analyzed by the application. In order to investigate the mechanism of a rotor system with unbalance and blade-casing rubbing coupling faults, the vibration and rub force in a rotor system resulting from unbalance and blade-casing rubbing coupling faults are simulated. At first, a dynamic model of form rotor is established, and a blade-casing model, which considered blade number, clearance between the blade tip and. TIP | 2 where Y is constant depending on the crack and sample shape, KIC is fracture toughness, and c is crack size. Glass having larger crack size, c, could broken at lower failure stress. Although the stress applied for glass is lower than the failure stress, crack can be propagated in . The rotor–stator rubbing in rotating machinery generated as a consequence of rotor imbalance, shaft misalignment, and casing deformation is a potential threat to the machinery that seriously affects its performance. Timely prediction and correction of the rubbing are essential for the prolonged life of the machinery and its overall performance.
The results show that the stacking sequences, rub positions, blade damping, and stiffness could have much impact on the relatively dangerous interaction regimes. With the help of this method, one can assist the design processes of the composite blade-casing interface in initial aero-engine structural designs. Prediction of Unsteady Tip Leakage Flow of a Transonic Compressor Rotor by Reynolds-Stress-Constrained Large Eddy Simulation Yueqing Zhuang, The turbulence statistical results show three distinct high flow fluctuation regions near the blade tip. The first one is a long and narrow strip ahead of the leading edge of the rotor caused by the. A common failure mode for turbine machine is high cycle of fatigue of compressor and turbine blades due to high dynamic stress caused by blade vibration and resonance within the operating range of. In the current facility configuration, a 90 deg sector of a representative engine casing is forced to rub the tip of a single-bladed compressor disk for a selected number of rubs with predetermined blade incursion into the casing at rotational speeds in the vicinity of 20, rpm .