426 CHAPTER 15 Bending of Open and Closed, Thin-Walled Beams
Fig.15.4
Bending of a symmetrical section beam.
Fig.15.5
Length of beam subjected to a pure bending moment.
hassufferedastrainεzwhichisgivenby
εz=
changeinlength
originallength
Then,
εz=
(R−y)δθ−δz
δz
thatis,
εz=
(R−y)δθ−Rδθ
Rδθ