Systems and methods for determining efficiency of friction welding processes

1. A method, comprising:

measuring, using a strain gauge, a workpiece torque experienced by a sample;

calculating, using a computing device, an energy associated with the workpiece torque; and

calculating, using the computing device, an efficiency of a rotary friction welding process using the energy associated with the workpiece torque.

2. The method of claim 1 , further comprising:

measuring a rotational velocity of the welding machine;

calculating a total torque required to cause a decrease in the rotational velocity of the welding machine; and

calculating an energy associated with the total torque, wherein the efficiency of the rotary friction welding process is calculated using the energy associated with the workpiece torque and the energy associated with the total torque.

3. The method of claim 2 , wherein the energy associated with the total torque is an instantaneous energy or a cumulative energy over a period of time.

4. The method of claim 2 , wherein the efficiency of the rotary friction welding process comprises a ratio between the energy associated with the workpiece torque and the energy associated with the total torque.

5. The method of claim 1 , further comprising using the efficiency of the rotary friction welding process in a computational thermal or thermal-stress model used to determine a parameter for the rotary friction welding process.

6. The method of claim 5 , wherein the parameter comprises at least one of axial load, moment of inertia of a flywheel for an inertia friction welding machine, initial rotational velocity or kinetic energy for the flywheel for the inertia friction welding machine, rotational speed of a direct drive welding machine, sample surface roughness, sample diameter, pre-heating temperature, welding time, burnoff length, or interface temperature.

7. The method of claim 1 , wherein

the strain gauge is attached to the sample.

8. The method of claim 1 , wherein the energy associated with the workpiece torque is an instantaneous energy or a cumulative energy over a period of time.

9. The method of claim 1 , further comprising obtaining a total energy supplied to the welding machine to spin the sample, wherein the efficiency of the rotary friction welding process is calculated as a ratio between the energy associated with the workpiece torque and the total energy.

10. The method of claim 1 , wherein the rotary friction welding process comprises inertia friction welding, continuous drive friction welding, hybrid friction welding, or orbital friction welding.

11. The method of claim 1 , further comprising using the efficiency of the rotary friction welding process to control the rotary friction welding process.

12. A system, comprising:

a torque load cell configured to measure a workpiece torque experienced by a sample; and

a processor and a memory operably coupled to the processor, wherein the memory has computer-executable instructions stored thereon that, when executed by the processor, cause the processor to:

receive the workpiece torque experienced by the sample;

calculate an energy associated with the workpiece torque; and

calculate an efficiency of a rotary friction welding process using the energy associated with the workpiece torque.

13. The system of claim 12 , the memory having further computer-executable instructions stored thereon that, when executed by the processor, cause the processor to:

receive a rotational velocity of a welding machine;

calculate a total torque required to cause a decrease in the rotational velocity of the welding machine; and

calculate an energy associated with the total torque, wherein the efficiency of the rotary friction welding process is calculated using the energy associated with the workpiece torque and the energy associated with the total torque.

14. The system of claim 13 , wherein the energy associated with the total torque is an instantaneous energy or a cumulative energy over a period of time.

15. The system of claim 13 , wherein the efficiency of the rotary friction welding process comprises a ratio between the energy associated with the workpiece torque and the energy associated with the total torque.

16. The system of claim 12 , wherein the torque load cell is attached to the sample.

17. The system of claim 12 , wherein the sample is a rotating or non-rotating sample.

18. The system of claim 12 , wherein the energy associated with the workpiece torque is an instantaneous energy or a cumulative energy over a period of time.

19. The system of claim 12 , the memory having further computer-executable instructions stored thereon that, when executed by the processor, cause the processor to receive a total energy supplied to the welding machine to spin the sample, wherein the efficiency of the rotary friction welding process is calculated as a ratio between the energy associated with the workpiece torque and the total energy.

20. The system of claim 12 , wherein the rotary friction welding process comprises inertia friction welding, continuous drive friction welding, hybrid friction welding, or orbital friction welding.

21. A non-transitory computer-readable recording medium having computer executable instructions stored thereon that, when executed by a processor, cause the processor to:

receive a workpiece torque experienced by a sample;

calculate an energy associated with the workpiece torque;

receive a rotational velocity of a welding machine;

calculate a total torque required to cause a decrease in the rotational velocity of the welding machine;

calculate an energy associated with the total torque; and

calculate an efficiency of a rotary friction welding process using the energy associated with the workpiece torque and the energy associated with the total torque.