Which of the following can be characterized with yield stress?     Thixotropy     Plastic behavior     Newtonian behavior     Pseudoplastic behavior

Which of the following statements is incorrect for polymers? (This question has only one correct answer) а. The fatigue behavior of polymers is more sensitive to loading frequency than for metals Ob. Amorphous and semi-crystalline polymers both have lower strength than crystalline polymers О с. Strength increases at higher temperatures as the material softens O d. It is desirable to have a ductile-to-brittle transition temperature below room temperature

Hooke's law is used to correlate true stress and true strain in the plastic region of the stress/strain curve.   true or false

(b) A cylindrical rod made from an unknown metal is 350mm long and has a diameter of 10mm. The rod is subjected to a tensile load. It experiences only elastic deformation and elongates by less than 1.0mm under an applied load of 19,800N. Could any of the four metals listed in the table below could be the unknown metal? If so which ones and why? Material Modulus of Yield Ultimate Elasticity / GPa Strength / MPa Tensile Strength / MPa Aluminium 70 255 420 alloy Brass 100 345 420 Copper alloy Steel 110 250 290 207 450 550

How do heat treatment techniques like quenching and tempering contribute to enhancing the mechanical properties of materials in the field of mechanical engineering?

The cylindrical tank has an inner diameter of 450 mm, the wall thickness is 6 mm, and point a is the most critical location. With a vacuum pressure of 1.5 MPa, a) using the von Mises criterion, is this a durable design? b) using the Mohr's criterion, is this a durable design?