A damage assessment methodology based on the Hashin failure theory for glass fiber reinforced polymer(GFRP)composite blade is proposed. The typical failure mechanisms including the fiber tension/compression and matrix...A damage assessment methodology based on the Hashin failure theory for glass fiber reinforced polymer(GFRP)composite blade is proposed. The typical failure mechanisms including the fiber tension/compression and matrix tension/compression are considered to describe the damage behaviors. To give the flapwise and edgewise loading along the blade span, the Blade Element Momentum Theory(BEMT) is adopted. In conjunction with the hydrodynamic analysis, the structural analysis of the composite blade is cooperatively performed with the Hashin damage model. The damage characteristics of the composite blade, under normal and extreme operational conditions,are comparatively analyzed. Numerical results demonstrate that the matrix tension damage is the most significant failure mode which occurs in the mid-span of the blade. The blade internal configurations including the box-beam, Ibeam, left-C beam and right-C beam are compared and analyzed. The GFRP and carbon fiber reinforced polymer(CFRP) are considered and combined. Numerical results show that the I-beam is the best structural type. The structural performance of composite tidal turbine blades could be improved by combining the GFRP and CFRP structure considering the damage and cost-effectiveness synthetically.展开更多
Carbon fiber reinforced polymer(CFRP)composites,as a typical difficult-to-machine material,exhibit high cutting forces and temperatures during actual machining,leading to more severe tool wear compared to traditional ...Carbon fiber reinforced polymer(CFRP)composites,as a typical difficult-to-machine material,exhibit high cutting forces and temperatures during actual machining,leading to more severe tool wear compared to traditional metal ma-terials.The shear fracture during fiber cutting is incomplete,resulting in surface defects such as unclosed fibers and burrs.To analyze the cutting forces and tool wear areas when cutting CFRP with different fiber angles,a three-dimensional or-thogonal cutting model of CFRP was established using finite element software and the VUMAT subroutine,based on the three-dimensional Hashin criterion.Simulation results show that during the cutting process of CFRP,high-stress areas appear in the region where the cutting edge contacts the workpiece for each fiber orientation,primarily concentrated in the first deformation zone in contact with the cutting edge.The Mises stress is highest when cutting the 90°fibers and lowest when cutting the 0°fibers.When cutting the 0°and 135°fibers,the tool is prone to wear on both the rake and flank faces,while when cutting the 45°and 90°fibers,the tool's rake face is more likely to experience wear.展开更多
基金financially supported by the Marine Renewable Energy Research Project of State Oceanic Administration of China(Grant No.GHME2013GC03)
文摘A damage assessment methodology based on the Hashin failure theory for glass fiber reinforced polymer(GFRP)composite blade is proposed. The typical failure mechanisms including the fiber tension/compression and matrix tension/compression are considered to describe the damage behaviors. To give the flapwise and edgewise loading along the blade span, the Blade Element Momentum Theory(BEMT) is adopted. In conjunction with the hydrodynamic analysis, the structural analysis of the composite blade is cooperatively performed with the Hashin damage model. The damage characteristics of the composite blade, under normal and extreme operational conditions,are comparatively analyzed. Numerical results demonstrate that the matrix tension damage is the most significant failure mode which occurs in the mid-span of the blade. The blade internal configurations including the box-beam, Ibeam, left-C beam and right-C beam are compared and analyzed. The GFRP and carbon fiber reinforced polymer(CFRP) are considered and combined. Numerical results show that the I-beam is the best structural type. The structural performance of composite tidal turbine blades could be improved by combining the GFRP and CFRP structure considering the damage and cost-effectiveness synthetically.
文摘Carbon fiber reinforced polymer(CFRP)composites,as a typical difficult-to-machine material,exhibit high cutting forces and temperatures during actual machining,leading to more severe tool wear compared to traditional metal ma-terials.The shear fracture during fiber cutting is incomplete,resulting in surface defects such as unclosed fibers and burrs.To analyze the cutting forces and tool wear areas when cutting CFRP with different fiber angles,a three-dimensional or-thogonal cutting model of CFRP was established using finite element software and the VUMAT subroutine,based on the three-dimensional Hashin criterion.Simulation results show that during the cutting process of CFRP,high-stress areas appear in the region where the cutting edge contacts the workpiece for each fiber orientation,primarily concentrated in the first deformation zone in contact with the cutting edge.The Mises stress is highest when cutting the 90°fibers and lowest when cutting the 0°fibers.When cutting the 0°and 135°fibers,the tool is prone to wear on both the rake and flank faces,while when cutting the 45°and 90°fibers,the tool's rake face is more likely to experience wear.
