Digital Certification

6:

• A computer-implemented method according to claim 1, in which test requirement criteria are transformed into a pre-defined format, comprising one or more of:
• step c) comprising the step of pre-defining the one or more analysis types;
• step b) additionally comprising the step of predefining input parameters;
• step b) additionally comprising the step of predefining load cases.

9:

• A computer-implemented method according to claim 1, in which the selected test is a bird ingestion test, comprising two parts:
• i. an initial impact representing one or more bird strikes;
• and
• ii. a resulting unbalance analysis.

10:

• A computer-implemented method according to claim 9, in which the unbalance is modelled using an approach selected from the following:
• i. a user-defined force;
• ii. a user-defined unbalance;
• iii. a calculated unbalance, calculated from a given mass and displacement;
• iv. a calculated unbalance, calculated by removing a fan or turbine blade.

11:

• A computer-implemented method according to claim 9, the method comprising:
• a) building a structural model of the drivetrain;
• b) solving the structural model of the drivetrain, using either
• i) an iterative quasi-static analysis
• or
• ii) a dynamic analysis
• of the structural model of the drivetrain;
• c) calculating the unbalance response of the rotor;
• wherein the analysis in step b) accounts for non-linear variation of bearing stiffness with load or rotation speed.

12:

• A computer-implemented method according to claim 11, in which the step of solving is a quasi-static iterative method, comprising the steps of:
• a) selecting a rotational speed;
• b) applying an unbalance to a rotor shaft;
• c) running a quasi-static structural analysis at the selected rotational speed;
• d) calculating bearing reaction forces;
• e) applying bearing reaction forces as a quasi-static load;
• f) repeating steps b) to e) until the analysis results converge;
• g) outputting the results for the given rotational speed.

14:

• A computer-implemented method according to claim 1, in which the selected test is a bird ingestion test or compressor and turbine blade failure test, wherein the test includes a calculation of one or more of the following as a function of shaft rotation angle:
• i. shaft deflection;
• ii. gear misalignment;
• iii. bearing misalignment;
• iv. gear contact stress;
• v. bearing contact stress.

16:

• A computer-implemented method according to claim 15, in which the test includes a calculation of one or more of the following:
• i. the natural frequencies and the associated mode shapes of the shafts;
• ii. a damped natural frequency map;
• iii. the kinetic and the strain energy as a function of speed for a component;
• iv. a trace over speed at specific positions, where the trace comprises one or more of velocity, acceleration, deflection, and stress;
• v. the value of one or more of velocity, acceleration, deflection, and stress at a specific speed.

17:

• A computer-implemented method according to claim 1, in which the selected test is a combination of one or more of the following:
• i. an endurance test;
• ii. an over-torque test;
• iii. an over-speed test;
• iv. an exhaust gas over-temperature test;
• v. an over-temperature test.

19:

• A computer-implemented method according to claim 18, in which the thermal analysis further comprises:
• building a structural meshed model based on the parametric description;
• building a meshed-thermal-model based on the structural meshed model;
• calculating a temperature distribution for one or more components of the drivetrain using:
• (i) the meshed-thermal-model;
• and (ii) one or more fluid temperatures associated with the drivetrain;
• determining the efficiency of one or more components of the drivetrain, based on the temperature distribution;
• and
• determining whether the drivetrain passes the certification test.