CHAOTIC PHENOMENA IN NONLINEAR MAGNETO-PIEZOELECTRIC ENERGY HARVESTER
Published In: 3RD INTERNATIONAL CONFERENCE ON ADVANCES IN CIVIL, STRUCTURAL AND MECHANICAL ENGINEERING
Author(s): DANUTA SADO , MAREK PIETRZAKOWSKI
Abstract: The presented analysis concerns the two-degree-of-freedom lumped parameter model, which is combined of the magneto-piezoelectric energy harvester and the mass-spring subsystem used as a dynamic magnifier. The simplified single-degree-of-freedom energy harvester describes the tip beam dynamics and the voltage generated by the piezoelements. The equivalent mass and stiffness of the cantilevered beam, and also the piezoelectric properties characterize this subsystem. The repulsive force created by the tip magnet and another one mounted to the cantilever base is involved. It is assumed that the repulsive loading component is a nonlinear odd function of the cantilever tip displacement and the energy harvesting subsystem can be modelled as Duffing oscillator. Changing the distance between the magnets, monostable or bistable behaviour of the beam harvester can be created. The presence of bistability improves the harvester effectiveness and also may create chaotic behaviour. For characterizing
- Publication Date: 27-May-2015
- DOI: 10.15224/978-1-63248-062-0-38
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3D SIMULATION OF STRESS IN GIRTH WELDING OF PIPELINE THERMAL ANALYSIS OF GIRTH WELDING IN PIPELINE
Published In: 3RD INTERNATIONAL CONFERENCE ON ADVANCES IN CIVIL, STRUCTURAL AND MECHANICAL ENGINEERING
Author(s): BIN WANG , BRIDGET KOGO , BRIDGET KOGO
Abstract: Welding is the primary joining technology used to make continuous pipelines in the industry. The thermal and mechanical loading in the process has a profound impact on the integrity of the pipeline over its service life. An accurate and thorough assessment is needed on the associated residual stress and its effect on the structural properties of the pipeline. 3D simulations of stress in girth welded pipe sections have been carried out using the Abaqus CAE software in two steps, the first being the thermal modelling with a moving hot spot and added mass whereas the second being the stress or mechanical analysis. In the Thermal Model, it was observed that the distribution of heat in the heat affected zone (HAZ) was maximal at the apex of the heat flux whereas minimum at the start and end points indicating that heat was trapped in the middle region which is responsible for the fluctuations in the heat distribution in these zones. Contour plots of these results further confirm same pattern
- Publication Date: 27-May-2015
- DOI: 10.15224/978-1-63248-062-0-56
- Views: 0
- Downloads: 0