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• High-sensitivity EFPI sensor capable of measuring a large range of strains. • Suitable for studying the effect of strain rate on mechanical properties. • Comparison with extensometer measurement results. • Comparison with FEM simulation results. This paper reports on the design and implementation of an innovative fiber optic sensor based on extrinsic Fabry-Perot interferometer (EFPI) to accurately measure the tensile strain of the Inconel 718 specimen. The measurement results were compared with the strain measured simultaneously by the electronic extensometer. The fast Fourier transform (FFT) method was used to obtain the cavity length from the real-time spectrum. The proposed EFPI sensor revealed a sensitivity of 26.59 nm/με and a strain measurement range of 166,000 με. By matching strain with the stress measured by tensile testing machine, the full stress-strain curves of the Inconel 718 specimen were obtained at different strain rates from 0.00001/s to 0.001/s. The finite element method (FEM) was used to verify the accuracy of the proposed EFPI sensor. [ABSTRACT FROM AUTHOR]

The life of turbine blades often determines the life of the aero-engine, and creep rupture is one of the main fracture forms of turbine blades in high temperature environments. In order to accurately predict the life of turbine blades, creep tensile tests of smooth specimens were carried out according to typical loads of 760 °C/800 MPa, 900 °C/445 MPa, 980 °C/400 MPa, 1000 °C/283 MPa and 1050 °C/210 MPa. With the help of crystal plasticity theory, creep constitutive equations with temperature interpolation were constructed. The FSI heat transfer analysis was performed to obtain the creep life of the turbine blades,. The temperature difference on the blade had reached 300 °C. With creep constitutive model and temperature boundary, the creep analysis of the blade was carried out and the creep process was revealed. The dangerous section of the global-model was obtained, and the sub-model was used to re-analyze the dangerous area. This paper reveals the deformation of the blade after creep failure: the middle part of the blade shrinks which is also the potential damage area, the top part expands, and the trailing edge of the blade tip produces a radial displacement of 0.313 mm after creep failure. The creep life of the turbine blades is determined to be 91 h. Finally, a method to determine the creep life of turbine blades was given based on skeletal point stress method. [ABSTRACT FROM AUTHOR]

Despite the emergence of various human-robot collaboration frameworks, most are not sufficiently flexible to adapt to users with different habits. In this article, a Multimodal Reinforcement Learning Human-Robot Collaboration (MRLC) framework is proposed. It integrates reinforcement learning into human-robot collaboration and continuously adapts to the user's habits in the process of collaboration with the user to achieve the effect of human-robot cointegration. With the user's multimodal features as states, the MRLC framework collects the user's speech through natural language processing and employs it to determine the reward of the actions made by the robot. Our experiments demonstrate that the MRLC framework can adapt to the user's habits after repeated learning and better understand the user's intention compared to traditional solutions. [ABSTRACT FROM AUTHOR]

A growing number of studies have been conducted over the past few years on the positioning of daily massage robots. However, most methods used for research have low interactivity, and a systematic method should be designed for accurate and intelligent positioning, thus compromising usability and user experience. In this study, a massage positioning algorithm with online learning capabilities is presented. The algorithm has the following main innovations: (1) autonomous massage localization can be achieved by gaining insights into natural human-machine interaction behavior and (2) online learning of user massage habits can be achieved by integrating recursive Bayesian ideas. As revealed by the experimental results, combining natural human-computer interaction and online learning with massage positioning is capable of helping people get rid of positioning aids, reducing their psychological and cognitive load, and achieving a more desirable positioning effect. Furthermore, the results of the analysis of user evaluations further verify the effectiveness of the algorithm. [ABSTRACT FROM AUTHOR]

Based on the turbine high-temperature combustion gas simulation test platform, the long-term combustion gas environment exposure test of the 2D plain woven SiC f /BN/SiC composites under two combustion conditions was carried out. Uniaxial tensile test, fracture morphology characterization and non-destructive testing analysis revealed the degradation and microstructure evolution of composites after exposure to combustion gas environment. The results show that the degradation of 2D-SiC f /SiC composites after exposure to combustion gas environment is manifested as a decrease in static toughness, and the interphase transition is the mesoscopic cause of the decrease in static toughness of the composite. [ABSTRACT FROM AUTHOR]