Papers by Keyword: Fatigue Durability

Abstract: The paper contains results of the first stage of experimental programme aimed at an evaluation of microstructure, mechanical properties, fatigue durability and creep of the first batch of Inconel 718 samples manufactured using the 3D printing technology, Direct Metal Laser-Sintering (DMLS). Specimens were printed in the X position with specimen axis perpendicular to the built direction. The results, compared with specimens manufactured conventionally, were completed and discussed with analyses of damage mechanisms particularly using scanning electron microscopy. Static strength of the printed material was significantly higher in comparison with conventional material. Fatigue resistance was comparable provided that there were no microstructure defects causing premature failure. High sensitivity to sever machining was demonstrated.

Abstract: One of the important methods to ensure the durability of cement concrete pavement is utilizing excellent waterproof bond layer. Firstly, based on the mechanism of strength of the thermosetting epoxy asphalt waterproof bond material (EAWBM), the construction temperature which is strictly controlled above 130°C, is insured. Then the amount, the curing time and temperature of the thermosetting epoxy asphalt, are studied as the influencing factors of mechanical properties based on the composite structures of the concrete cement pavement. Finally, through the three-point bending fatigue test of composite structures, the fatigue durability of different waterproof bond material is compared. The results show that: the optimal amount of the thermosetting epoxy asphalt is 0.60~0.80L/m²; the asphalt concrete paving must be carried out within 24~32h after the EAWBM is constructed; the mechanical properties of the material decreases as the increasing test temperature; the waterproof bond materials have greater impact on the fatigue durability for the composite structures of the concrete cement pavement compared with the paving material, and the fatigue durability of the EAWBM is the optimal selection for cement concrete pavement.