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Recently, we develop a new method for reducing vibration named liquid film damping (LFD) which combines the mechanism of vibrational energy dissipation of liquid viscous damping (LVD) and air film damping (AFD). This paper use experiment to compare the capacities of vibration decreasing of LFD and the pore viscous damping (PVD) which is an extensive applied type of LVD. The results of experiment present LFD has better ability than traditional LVD in reducing vibration of structures in not only higher frequency but lower frequency.

The vibration of pipe systems not only worsens their working environment, but also may result in the loosening of mechanical connections between pipelines, as well as the structural fatigue damages. This paper presents a new method for vibration control of pipe systems, by specially designing some pipe structures based on two vibration reduction mechanisms of phononic crystals, for the vibration frequency in the actual tests. Some numerical analyses are then performed about the effects of the parameters of vibrator, for instance, the ratio of material components, and the numbers of period. The simulation results demonstrate that the proposed phononic crystals structures can reduce the vibration of pipe systems effectively.

Elastic constants of purity and containing impurity metal aluminum were calculated, and the effects of impurity on the elastic constants were also studied. The effect of particle on micro-stress concentration and debonded stress of inclusion was researched. The mechanical relationship between the grains was defined by relationship of displacement and driving force in cohesion zone model (CZM).The method can be extended to research mechanical properties of other metals and alloys structures.

Through the analysis of the thermal state model of the wire, it is considered that the temperature rise is the characteristic parameter to measure the working state of the wire, which is related to the actual heat dissipation coefficient and heat dissipation surface area, and is determined by practical factors such as laying mode, operating current and thermal load, and external working condition. A method to determine its thermal state by obtaining infrared temperature spectrum is proposed, and the relatively stable temperature rise is taken as the evaluation index. The vibration condition promotes the establishment of heat exchange and its equilibrium. Different laying methods have different sensitivity to vibration and thermal stress.