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If the specimen is deformed plastically beyond the yield stress in one direction, e.g., tension and then after unloading it is loaded in the opposite direction, e.g., compression, it is found that the yield stress is less than the original yield stress. This dependence of yield stress on direction loading is called ____________

Correct Answer: bauschinger effect
Bauschinger effect is the phenomena which account for the difference in yield strength of the material in different directions of loading and unloading path. Following diagram show the effect. Strain hardening is a phenomenon in which the required stress increases for deformation with increases in strain. Residual stress is the remaining stress in the material after unloading. Nabarro–Herring effect is associated with creep.

From an alloy, two specimens are machined and tested separately under tension and compression. The engineering stress-strain curves as well as the true stress-true strain curves for tension and compression are plotted in the same diagram. Identify the correct statements:
P. The engineering stress-strain curves in tension and compression are identical.
Q. The true stress-true strain curve in compression is lower than the true stresstrue strain curve in tension due to Bauschinger effect.
R. The true stress-true strain curve in tension is above the corresponding engineering stress-strain, curve.
S. The true stress-true strain curve in tension and compression are identical.

The behaviour of a metal specimen, which when plastically strained in tension reduces its yield stress in compression and vice versa; is termed as the

A metallic sheet 1 m wide and 10 mm thick is to be rolled under a front tension force of 100 KN. A specimen from the sheet, tested under tension, shows a yield stress of 100 MPa. Assume plain strain condition during rolling and ignore the friction. If yielding is assumed to start at a roll pressure of σ3 MPa, then the stress in the width direction (where strain is zero) is

A zinc crystal is strained to point A, unloaded, and then reloaded in the direction opposite to the original slip direction: What is the reason for the drop in shear stress when loaded in the opposite direction?

To obtain super-plasticity, the alloy should
P. have a fine grain structure that is also stable at high temperature
Q. be deformed at low temperature
R. be deformed at low strain rates
S. be deformed at high strain rates

A rock specimen of 120 mm length and 54 mm diameter is subjected to uniaxial compressive loading. Two strain gauges, one axially and other radially, are attached to the specimen. At the breaking load, if these two gauges read 0.0082 m/m and 0.0023 m/m respectively, the Poisson's ratio of the specimen is

To obtain better memory utilization, dynamic loading is used. With dynamic loading, a routine is not loaded until it is called. For implementing dynamic loading ____________

Tresca or maximum-shear stress criteria assumes that yielding occurs when the maximum shear stress reaches a value of the shear stress in the uniaxial tension test. Assume the principal stress being σ1, σ2, σ3 where σ1 is largest, and σ3 is the smallest principal stresses. Find the value of minimum shear stress to cause yielding, given that yield stress in tension is equal to σo?

The maximum harbour depth below lowest low water is generally equal to
(i) loaded draft + 1.2 m when bottom is rock
(ii) loaded draft + 1.8 m when bottom is soft
(iii) loaded draft + 1.2 m when bottom is soft
(iv) loaded draft + 1.8 m when bottom is rock

Determine the correctness or otherwise of the following Assertion (a) and Reason (r).
Assertion: During rolling, front tension and (or) back tension are (is) employed to decrease rolling load.
Reason: Roll pressure decreases due to lowering of flow stress as a result of front tension/back tension.