On the Strength of Ductile Materials under Combined Stress

Abstract

1. Lack of knowledge of lams of strength.2. Separation of the isotropic materials into ductile m d brittle, 3, The yield-point in Tension Tests.4. The yield-point, rather than the ultimate, stl*ess the criterion of strength.5. Variations of the ultimate and yield-point stresses : annealing.6.The elastic limit. 7.The elastic-limit effect probably due to the existence of local yield-8.The yield-point, in preference to the clastic limit, selected as the 9. Torsion a case of combined stress.points.criterion of sbrength.10. First reason for use of thin tubes as specimens.11. Results of previous torsion experimentd.12, Previous experiments upon the yield-point under combined stress.13.Experiments upon ultimate strength under combined stress.14.Theories of elastic strength under combined stress : the maximum 15, The maximum strain theory.18, Theorem upon the limiting values of U . 17.The niaximum strain theory not disproved by published experiments. 18.The niaximum shearing-stress criterion of elastic strength.19.Further reasons for adopting thiu tubes as specimens.20, Range of stress covered by diferent types of experiment.21.Method of checking the isotropism of the material asregards yield-point 22. Objections to tubes 011 account of want of isotropy.23, Objections to tubes on account of large effect of defects.24.The system of Tests.25, The specimeiis and holders.28.The tension loads.57.The application of torque.28.The friction of the torsion-rigging.29, The application of the interual pressure.30.Measurement of the fluid pressure.31.A new type of pressure-gauge.32.Measurement of the distorsions.33.A new Extensometer.stress theory.stresses.