In this paper, rod drawing process of strain-hardening materials is investigated by analytical, numerical and experimental methods. The classic upper bound solution, based on the assumption of perfect plasticity, has been extended to consider the work-hardening of the material during the drawing process. For a given process conditions and mechanical properties of the rod material, the power ter...

Safety analysis has been done for the torsion of a functionally graded thick-walled  circular cylinder under internal and external pressure subjected to thermal loading. In order to determine stresses the concept of Seth’s transition theory based on generalized principal strain measure has been used. This theory simplifies the set of mechanical equations by mentioning the order of the measure of...

A continuum thermodynamics formulation for micromagnetics coupled with mechanics is devised to model the evolution of magnetic domain and martensite twin structures in ferromagnetic shape memory alloys. The theory falls into the class of phase-field or diffuseinterface modeling approaches. In addition to the standard mechanical and magnetic balance laws, two sets of micro-forces and their assoc...

We analyze the onset of ‘necking’ and subsequent filament failure during the transient uniaxial elongation of viscoelastic fluid samples in extensional rheometers. In the limit of rapid elongation (such that no molecular relaxation occurs) the external work applied is all stored elastically and the Considère criterion originally developed in solid mechanics can be used to quantitatively predict...

in the first impounding of rockfill dams, additional settlements occur in upstream side in saturated rockfills due to collapse phenomenon even high rainy seasons can cause additional deformation in the dumped rockfills. unfortunately these displacements are not taken into account in the conventional numerical models which are currently used to predict embankment dam behavior during impounding. ...

in this work, dynamic mechanical properties of three high-manganese steels with trip/twip or fully twip characteristics are studied. high strain rate experiments in the range of true strain rates between ~500 and 1800 /s are conducted using a dynamic torsional testing setup. all the three steels show a positive strain rate sensitivity in the intermediate range of strain rates (up to 500 /s). bu...

The first quantitative analysis of the forward flow in frictionless rolling contact, firstly discovered experimentally by Crook [Proc. Inst. Mech. Eng. London 171 (1957) 187], was conducted by Merwin [Plastic deformation of surfaces in rolling, Ph.D. Dissertation, Cambridge University, UK, 1962] who attempted to model the ratchetting phenomenon in excess of shakedown (the cumulative forward flo...

The ultimate strength of carbon nanotubes is investigated by large-scale quantum calculations. While the formation energy of strain-induced topological defects determines the thermodynamic limits of the elastic response and of mechanical resistance to applied tension, it is found that the activation barriers for the formation of such defects are much larger than estimated previously. The theore...

We analyze in detail the atomistic response of a model amorphous material submitted to plastic shear in the athermal, quasi-static limit. After a linear stress-strain behavior, the system undergoes a noisy plastic flow. We show that the plastic flow is spatially heterogeneous. Two kinds of plastic events occur in the system: quadrupolar localized rearrangements, and shear bands. The analysis of...

In this paper we analyze a broad class of abstract doubly nonlinear evolution equations in Banach spaces, driven by nonsmooth and nonconvex energies. We provide some general sufficient conditions, on the dissipation potential and the energy functional, for existence of solutions to the related Cauchy problem. We prove our main existence result by passing to the limit in a time-discretization sc...