To determine helicopter component retirement intervals, it is common for fatigue engineers to utilize Miner’s rule for cumulative damage. Time consuming Monte Carlo simulations are considered the state of the art method for determining reliability in the presence of load variations. However, a new set of methods employed on a recent AHS fatigue reliability round robin problem provide an indicat...

H : specific total enthalpy α : angle of attack h : specific static enthalpy β : sideslip (yaw) angle J r : mass diffusion flux vector γs : recombination coefficient L : characteristic length ∆s : wall-normal grid spacing M : Mach number or molar mass ε : emissivity n : unit normal κ : gas mixture thermal conductivity p : Pressure μ : gas mixture viscosity Q : heat load σ : Stefan-Boltzmann con...

In the current work, the mesh free Smoothed Particle Hydrodynamics (SPH) method, was employed to numerically investigate the transient flow of a viscoplastic material. Using this method, large deformation of the sample and its free surface boundary were captured without the cumbersome process of the grid generation. This three-step SPH scheme employs an explicit predictor-corrector technique an...

Abstract Using molecular dynamics simulation, we investigate multiple scratching processes in which a tip moves through groove that has already been formed during previous scratch. We use conical indenter such the friction coefficient is independent of scratch depth. First, single to depth 4 nm compared with 2-cycle at 2 followed by second full nm. observe cycle shows smaller as long pre-formed...

In the discrete element simulation of granular materials, the modelling of contacts is crucial for the prediction of the macroscopic material behaviour. From the tribological point of view, friction at contacts needs to be modelled carefully, as it depends on several factors, e.g. contact normal load or temperature to name only two. In discrete element method (DEM) simulations the usage of Coul...

In recent years several catastrophic power systems blackouts have occurred worldwide. Various reasons have been declared for these failures. Economical limitations due to power system restructuring restrictions, inadvertent operation of protective relays and inefficient design of conventional load shedding schemes are of the most important reasons causing these blackouts. In fact, due to both e...

In this article, the nonlocal biaxial buckling load and bending analysis of polymeric piezoelectric nanoplate reinforced by carbon nanotube (CNT) considering the surface stress effect is presented. This plate is subjected to electro-magneto-mechanical loadings. Eshelby-Mori-Tanaka approach is used for defining the piezoelectric nanoplate material properties. Navier’s type solution is employed t...