Failure analysis of a high mast lamp post

The failure of a high mast lamp post was analysed. The mast failed by bending at a position just opposite to the maintenance pocket. It appears that the failure was due to wind load, which the structure could not bear. The elemental analysis and mechanical properties determination of the failed mast materials was as per the recommended values. However, the mechanical properties were slightly higher compare to recommended values and this is because of the presence of very fine pearlite in the microstructure. The probable causes might be due to faulty installation and/or damage during installation, severe weather condition or events such as high-speed storm, etc. or fatigue caused by the unpredictable phenomenon of harmonic vibration.