Papers by Keyword: Static Properties

Abstract: Ti-6Al-4V is the most common used titanium alloy in aerospace. Parts are therefore often machined from wrought material with high buy-to-fly ratios. Additive manufacturing, however, allows to build parts rapidly and directly from computer-aided design information, offering better material utilisation and lead time reduction. Despite the high potential for aerospace applications, the reliability of the mechanical properties is still at an early stage. This work should give a first overview by determining and comparing DMLS, EBM and DMD Ti-6Al-4V material. Each process is compared based on standardised post treatments, specimen geometries and test methods.It can be seen that the chemistry, the microstructure, and the defect formation differs between the processes, which leads to a scatter in the experimentally determined static tensile, axial fatigue, and crack growth properties.

Abstract: Static and dynamic characteristic of carbon nanotube is analyzed by molecular dynamic simulation. Static analysis show that maximum deflection of carbon nanotube appears at 0.033nm distance from free end of cantilever. When the value of driving voltage is less, the flexibility is more important, then the stiffness increase with the voltage increasing, and the collapse structure or hole appear on carbon nanobute. Under low pressure condition, deflection difference on equi-increase of pressure between no damping and damping simulation is larger than that on high pressure. The results of forced vibration indicate that system response consist of transient and steady-state response. With steps of molecular dynamic simulation increasing, transient response disappears gradually, so system response includes only steady-state response, which is simple harmonic vibration with the same frequency as excitation force. These results are in accord with the classical vibration theory. Moreover they will provide theoretic foundation for designing of nanostructure device.