In the cross section, {HEAD ~ the lower flange} is thicker than the upper flange and the lower flange is wider than the upper flange, and {TAIL ~ the neutral axis} of upward/downward bending 
In the cross section , { HEAD ~ the lower flange } is thicker than the upper flange and the lower flange is wider than the upper flange , and { TAIL ~ the neutral axis } of upward / downward bending
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH