Increasing operating temperature plays a critical role in improving the thermal efficiency of gas turbines. This paper assesses the capability of advanced thermal barrier coatings being developed for use in 1700 °C class gas turbines. Parts sprayed with these coatings were evaluated and found to have excellent durability and long-term reliability.

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In this study, the damping effects of an impact damper which consists of a vessel and elasto-plastic balls are evaluated. Lead is employed as an elasto-plastic material. Numerical simulations are performed based on a discrete element method. In the numerical simulations, the impact force modeling is modified so as that the elasto-plasticity of the material can be considered. And the rotation of a particle is also considered to simulate the actual particle behaviors at the collision. Frequency responses of the vessel and the damping effect of the damper are evaluated for 2 kinds of impact force models. Also, the effects of vessel dimensions, vessel configurations and the excitation directions are investigated. As a result, the effects of the above mentioned parameters are clarified.

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The conventiona ユstudies o ロ the granuEac material impact dampers ， rarely take the dependency of restitution coeficient on relative impact velocity due to elasto − plastic deforlnation at the impact into consideratioIl ． III this paper ， elasto − plastic materials su 〔h as lead are treated ． The elasto − plastic behavior at the impact is modeled as a bi − linear type force − displacement characteristics ． Impact behaviors in the horizontal and vertical plane are evaluated by numerical simulations ， and the viblation mitigatioll capability is investigated for vamious container configurations ．