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A 3D model of a middle-size olive tree has been analyzed considering various shaking conditions by using an attached trunk shaker to improve the harvesting rate as regards the critical nodal acceleration and displacement. The effects of shaking frequency, loading type as well as temperature and loading height were simulated and investigated on olive-stem-twig joint rupture. Comparing the results of finite element modal analysis in ABAQUS 6.10 with those of field experiments, utilizing a hydraulic eccentric-mass trunk shaker, exhibits less than 5% deviation at frequencies between 10 to 25 Hz at the first four vibration modes with damping ratio of 16-30%. The experiments and simulations show the maximum harvested quantity of sample middle-size olive trees is 92% and 96%, respectively. It is acquired at f=20 Hz, T=28°C for 45% moisture content of wood in late November 2012, without chemicals. The optimized mechanical harvesting yielded the lower number of workers, time saving (~12 tree/hr), and to improve the obtained productivity (293 kg/hr). The results imply that accurate 3D analysis of mechanized olive harvesting can be an efficacious solution to obtain desired parameters and optimal efficiency, which is comparable to manual method.

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Lead zirconate-titanate (PZT) thick films of perovskite structure Pb(Zr x Ti 1-x )O 3 were fabricated on the curved surface of IN738 nickel-based supper alloy substrate up to 15 mm thickness using sol-gel deposition technique without polyvinylpyrrolidone. The films were heated at 200 C with 10 wt% excess PbO, pyrolyzed at 400 C, and subsequently annealed at 650 C, 700 C, and 800 C. Au and Pt thin films were deposited as bottom and top electrodes, respectively. PZT films of different thicknesses and thermal treatment conditions were characterized to investigate the effect of process on crystalline phase development, orientation, and microstructure morphology. Thereby, formation of fairly smooth, semi-dense, and crack-free random orientated thick films as well as an increase in the average grain size and stress relaxation was observed as the film thickness increased. Having optimized the coating process, intrinsic and extrinsic dielectric, ferroelectric and piezoelectric properties were measured as a function of the film thickness, orientation, grain size, and domain wall motions to evaluate the remnant polarization (P r ¼ 7.6-17.5 mC/cm 2 ), coercive field (E c ¼ 2.5-4 kV/ cm), permittivity (" r ¼ 276-326), dielectric loss (tan(%) ¼ 2.7-3), and piezoelectric charge coefficient (d 33 ¼ 71-145 pm/ V) of the PZT thick films prepared potentially to be used as high bandwidth 1-5 MHz structural health monitoring transducers.

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Resonant magnetostrictive transducers are used for generating vibrations in the sonic and ultrasonic range of frequency. As the mechanical properties of magnetostrictive materials change according to different operating conditions (i.e., temperature, mechanical prestress, and magnetic bias), the vibrational behavior of the transducer changes too.ΔEeffect is the change in the Young modulus of the ferromagnetic material and it has to be considered as it leads to changes in the dynamics of the transducer. This paper deals with the study of such effect from both theoretical and experimental point of view.ΔEeffect on behavior of the transducer based on Terfenol-D is analytically described as a function of different operating conditions focusing on effects on resonance frequency, mode shape, and moreover experimentally the quality factor. Results of resonance frequency prediction have been validated with experiments and good agreement has been seen.

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