At a critical point in a steel part of a machine, the stress components found were σxx = 100 mpa, σyy = −50 mpa and σxy = 30 mpa. assuming the point is in state stress plane, and the material yield stress to be 160 mpa, determine whether the fails according to the criteria: (a) the maximum shear stress (tresca). (b) the maximum deformation energy (von mises).

Describe one experiment in which the glass transition temperature and melting temperature of a totally amorphous thermoplastic material can be determined. show the relevant experimental results in a diagram which should be properly annotated with the two temperatures clearly marked. what is likely to happen to the curve in the diagram if the amorphous polymer is replaced by a thermosetting type?