Research On The Mechanism And Simulation Methodology Deyelopment For Aeroengine Casing/Blade Containment

The containment process of failed rotor blades is very complex, which involves high-energy, high-speed interactions of numerous locally and remotely located engine components. It includes every nonlinear aspect of structural dynamics, such as large displacements, plastic behavior of the materials, and contact interaction between structural elements. It is of great importance to systematically and deeply study the containment of failed rotor blades for the improvement in both safety and design of aeroengine. To this end, the main researches are as follows:(1) A comparative study involving aeroengine fan casing and plate target impacted by blade-like and cylindrical projectiles has been conducted. Based on the ballist impact tests carried out on the compressed gas gun, theoretical method has been used to analyze the perforation resistance of the target and the penetration capability of the projectile. For this purpose, the energy absorption modes of the target are classified and each mode is established with a corresponding theoretical model, among which, a new dishing energy calculation approach for an arbitrary cross-section projectile impact is proposed. The cause why the blade-like projectile nose shatters and the transformation mechanism of the failure mode on the target are also analyzed using theoretical methods. Moreover, the effects of yaw angle on the perforation process by the blade-like projectile have been investigated using numerical simulations.(2) Simulation methodology for aeroengine failed blade containment analysis has been developed. One test selected from nine blade/case containment tests conducted on the high speed spin test facility is simulated with different finite element models using the com-mercially available explicit dynamic analysis code ANSYS/LS-DYNA to assess the effects of mesh size, contact penalty factor and friction coefficient on numerical simulations, wherein a numerical method for metal blade/case containment simulation is formed and developed. Then, the developed simulation method is applied to the other eight tests and good agreements are in general obtained between the numerical and the test results. (3) The mechamism of the containment of failed fan blade has been investigated in detail. Firstly, numerical simulations for the containment analysis are conducted using the proposed simulation method, then, containment tests are carried out to validate the numerical results and the application of the proposed simulation method to real aeroengine fan blade containment analysis. Based on the validated FEM model, the mechamism of the containment of failed aeoegine fan blade is studied deeply and in detail.(4) The containment of aeroengine turbine blade has been studied systematically. Similar to the research method for the containment of the fan blade, numerical simulations are validated through containment tests. It reveals that the applicability of the proposed simulation method to real aeroengine turbine blade containment analysis. Using numerical method, the containment of aeroengine turbine blade is studied systematically. It is found that the differences of the containment mechanism between the turbine and the fan components are large. Multi-blade effects and the influences of the released speed on the containment capability of the turbine casing depend on the impact angle and the impact location on the casing.