Fatigue is the primary cause of failure of crankshafts in internal combustion engines. The cyclic loading conditions and the stress concentrations in the crank pin fillets are unavoidable, and can result in fatigue failure. The objectives of this study were to compare the fatigue behavior of forged steel and ductile iron crankshafts from a one-cylinder engine as well as to determine if the fati...

Single Point Diamond Turning (SPDT) experiments conducted on single crystal 6-H Silicon Carbide (SiC) has shown chip formation similar to that seen in the machining of metals. The ductile nature of SiC is believed to be the result of a high pressure phase transformation (HPPT), which generates a plastic zone of material that behaves in a metallic manner. This metallic behavior is the basis for ...

Yuemin Sun and Efthimios Kaxiras (a) Division of Applied Sciences, Harvard University, Cambridge MA 02138 (b) Department of Physics, Harvard University, Cambridge MA 02138 We conisder the brittle versus ductile behavior of aluminum in the framework of the Peierls-model analysis of dislocation emission from a crack tip. To this end, we perform first-principles quantum mechanical calculations for...

Brittle materials are materials that display Hookean behavior (linear relationship between stress and strain) and which fail at a discrete strain. Plastic materials display a variety of yielding behaviors associated with changes in the internal structure of the material at a fixed level of strain and at a fixed rate of strain. The time dependence to yielding behavior is due to the structural ch...

Cubic silicon carbide (SiC) is an extremely hard and brittle material having unique blend of material properties which makes it suitable candidate for microelectromechanical systems and nanoelectromechanical systems applications. Although, SiC can be machined in ductile regime at nanoscale through single-point diamond turning process, the root cause of the ductile response of SiC has not been u...

A novel numerical approach to analyze the mechanical behavior within composite materials including inelastic regime up final failure is presented. Therefore, a second-gradient theory combined with phase-field methods fracture. In particular, we assume that polymeric matrix material undergoes ductile fracture, whereas continuously embedded fibers undergo brittle fracture as it typical e.g. for r...

In this study, a practical seismic retrofit method for RC frames was proposed. For purpose, quasi-static loading applied to 8 different type of in finite elements analysis software, Abaqus and were pushed 45mm laterally. High strength fiber reinforced lightweight concrete panels used strengthen infill walls inside the frames. To apply them walls, epoxy binder polyurethane their behaviour compar...

Numerical studies of the ductile-brittle transition are described that are based on incorporating physically based models of the competing fracture mechanisms into the material's constitutive relation. An elastic-viscoplastic constitutive relation for a porous plastic solid is used to model ductile fracture by the nucleation and subsequent growth of voids to coalescence. Cleavage is modeled in ...

A numerical fragmentation model is proposed to predict the mechanical response of intermingled, unidirectional hybrid composites under tensile loads. The based on a previously developed for considering critical number fiber breaks and correction fiber-matrix interfacial strength. Hybrids comprising two reinforcements are considered, energetic contribution evaluated during damage process. Additi...