Plastic Flow and Fracture in Round Bars under Pure Torsion Sadia Makky Indiana University Mathematics Journal 1961 text pdf 10.1512/iumj.1961.10.10014 10.1512/iumj.1961.10.10014 en Indiana Univ. Math. J. 10 (1961) 199 - 221 state-of-the-art mathematics http://iumj.org/access/