The predictions of residual stresses are most critical on the machined aerospace components for the safety of the aircraft. In this paper, an enhanced analytic elasto-plastic model is presented using the superposition of thermal and mechanical stresses on the workpiece, followed by a relaxation procedure. Theoretical residual stress predictions are verified experimentally with X-ray diffraction...

We show experimentally that unpassivated freestanding nanoscale metal films, subjected to uniaxial tension, show substantial Bauschinger effect (BE) during unloading, even at large overall tensile stresses. Aluminum films (thickness 200–400 nm, grain size 200 nm) show BE at stresses as high as 150 MPa and their plastic strain after unloading is often less than 50% of the expected value. In gold...

In this paper, we investigate the effects of the non-singular stress (T stress) on the mode I near-tip fields lbr elastic perfectly plastic pressure-sensitive materials under plane-stress and small-scale yielding conditions. The T stress is the normal stress parallel to the crack faces. The yield criterion for pressure-sensitive materials is described by a linear combination of the effective st...

Transition theory has been used to derive the elastic-plastic and transitional stresses. Results obtained have been discussed numerically and depicted graphically. It has been observed that for disc with exponentially varying thickness (k=2), high angular speed is required for initial yielding at internal surface as compared to the flat disc and exponentially varying thickness for k=4 onwards. ...

Yield functions and plastic potentials are expressed in terms of the invariants of the stress tensor for polycrystalline metals and other isotropic materials. The plastic volume change data of Richmond is used to evaluate the embedded materials properties for some bcc metals and one polymer. A general form for the plastic potential is found that is intended to represent and cover a wide range o...

Fatigue is defined as 'Failure under a repeated or otherwise varying load, which never reaches a level sufficient to cause failure in a single application.' Fatigue cracks always develop as a result of cyclic plastic deformation in a localised area. This plastic deformation often arises, not due to theoretical stresses in a perfect part, but rather due to the presence of a small crack or pre-ex...

The manufacturing of components for aero engine structures from a flat sheet to the final shape usually requires several steps that may introduce residual stresses and shape distortions in the part. Depending on the magnitude, sign and distribution with respect to the stresses induced by the service load, the remaining stresses may affect the service life of a component, especially when submitt...