This paper investigates the dynamics of the engine driveline system for achieving accurate and online diagnostics of engine conditions using instantaneous angular speed (IAS). Based on a state space modelling approach and key structures of the system, a torsional vibration model is developed and its modal properties: modal frequency, damping ratio and shapes are evaluated. Then taking the outpu...

An approximate numerical mthod is presented for analysis and determination of modal characteristics in straight, pretwisted non-unifom helicopter blades. The analysis considers the coupled flapwise bending (out of plane), chordwise bending (in plane), and torsion vibration of both rotating and non-rotating blades. The proposed method is based on the integral expansion of Green functions (struct...

The present study set out to investigate the effect of teaching substitution as a kind of grammatical cohesion on the true identification of confusing substitution elements with cohesive or non-cohesive roles in different contexts and also the production of modal, reporting and conditional contexts through clausal substitution acquaintance. To this end, the following procedures were taken. Firs...