Using the IEC Simple Load Model for Small Wind Turbines - Small Wind Turbines: Analysis, Design, and Application - page 197

Simple Load Model Results

Load C ase A - Fatigue Loads on Blades and Rotor Shaft

Fatigue Damage Limit Fatigue Damage Conclusion

Blades 1.00 2.25E-06 SAFE

Shaft 1.00 Infinite Life SAFE

Load C ase B - Blade and Rotor Shaft Loads during Yaw

Material Stress Limit (MPa) Calculated Stress (MPa) Conclusion

Blades 13.33 0.27 SAFE

Shaft 27.78 40.29 FAIL

Load C ase C - Yaw Error Load on Blades

Material Stress Limit (MPa) Calculated Stress (MPa) Conclusion

Blades 13.33 2.77 SAFE

Load C ase D - Maximum Thrust on Shaft

Material Stress Limit (MPa) Calculated Stress (MPa) Conclusion

Shaft 13.33 0.65 SAFE

Load C ase E - Maximum Rotational Speed

Material Stress Limit (MPa) Calculated Stress (MPa) Conclusion

Blades 13.33 4.25 SAFE

Shaft 27.78 1.14 SAFE

Load C ase F - Short at Load Connection

Material Stress Limit (MPa) Calculated Stress (MPa) Conclusion

Blades 13.33 2.49 SAFE

Shaft 27.78 12.78 SAFE

Load C ase G - Shutdown Braking

Material Stress Limit (MPa) Calculated Stress (MPa) Conclusion

Blades 13.33 n/a n/a

Shaft 27.78 n/a n/a

Load C ase H - Parked Wind Loads during Idling

Material Stress Limit (MPa) Calculated Stress (MPa) Conclusion

Blades 13.33 3.58 SAFE

Shaft 27.78 1.86 SAFE

Fig. 9.7 The seventh sheet of the SLM spreadsheet

will no doubt become more popular, but it is not easy to implement. Readers
interested in pursuing this topic should start with the programs available from the
excellent NREL site: http://wind.nrel.gov/designcodes/simulators/ . Some of the
impressive results that can be obtained from aero-elastic simulations are described