Abstract Electron backscatter diffraction (EBSD) is an important technique for analyzing the microstructure of materials. Unfortunately, EBSD images obtained by experimental means often suffer from ...different types of information loss, which affect the subsequent experimental analysis. Our study aims to study an EBSD image restoration method based on deep learning, which can solve the problem of various defects in EBSD imaging process. This paper proposes MSA-GAN: A multi-scale image restoration method based on generative adversarial networks (GAN) and feature pyramids (ASPP). To construct a dataset for training the model, a mask generation method based on cellular automata is proposed to simulate the information loss in EBSD images. The experimental results show that the MSA-GAN method can effectively restore large, medium and small types of defects in EBSD images, and achieve better results than other restoration methods, improving the quality and accuracy of the digital microstructure images. Our study provides a new technical means for the analysis of material microstructures, which has important theoretical and practical value.
Abstract The high-pressure turbine blade in aero-engine power system may experience microstructural degradation due to uncertain flaws, multi-physical fields and loads during manufacturing, ...processing, installation, and maintenance, leading to serious structure deterioration that affects safety and reliability in service. Therefore, it is necessary to assess the influence of random flaws and loads on the fatigue performance of turbine blades from a probabilistic perspective. In this study, we propose a novel method based on the Artificial Hummingbird Algorithm and Kriging surrogate model (AHA-Kriging), for flaw tolerance assessment in the surface partition of the turbine blade. The results indicate that in the hazardous zone, the flaw tolerance reliability is 0.9984, corresponding to a LCF life of 1520 cycles. In the safe zone, the flaw tolerance reliability is 0.9991, corresponding to a LCF life of 2501 cycles. The primary factor influencing LCF life is flaw size, followed by factors such as the strength coefficient, gas temperature, and fatigue strength exponent. Besides, the AHA-Kriging approach exhibits higher modeling precision and simulation efficiency compared to other methods. This paper presents a practical engineering approach for assessing flaw tolerance in the surface partition of complex components, which is of significant value.
•Discover competitive cracking behavior in accelerated CCF failure for turbine blades.•Find crack initiation change from slip planes to metallic pores and carbides, to oxides.•Reveal damage ...mechanisms in acceleration states by microstructural dominant features.•The source of cracking transition from transgranular to intergranular mode is the detected behavior.•Provide a promising mechanism insight for CCF estimation and acceleration test.
The cracking behavior and microscopic mechanism of K403 superalloy turbine blade are investigated respecting the Combined high and low Cycle Fatigue (CCF) with four acceleration states. It concludes that: (1) the crack initiation sites transform from slip planes inside alloy matrix to subsurface pores and carbides, then to oxides outside surface with increasing loads; (2) the behavior in (1) is attributed to the competition and alliance of different microstructural factors and the interaction of the factors with grain boundaries; (3) hereinto, the role shift of high cycle fatigue in CCF causes the transformation of transgranular to intergranular cracking mode.
Two-dimensional (2D) Nb 2 CT X MXene has outstanding physicochemical properties and great potential in biochemical sensing applications. Here, we proposed and designed an ultrasensitive microfiber ...sensor integrated with Nb 2 CT X nanosheets and tested its BOD detection power. The Nb 2 CT X nanosheets were coated on the microfiber surfaces to enhance BOD sensing performance. The Nb 2 CT X nanosheets have a sheet-like structure, large specific surface area, and hydrophilic surface functional groups that significantly increase light-matter interactions and refractive index modulation around the microfiber. The transmission spectrum red shift significantly increases with BOD concentration whereas the transmission spectrum blue shift significantly increases with external temperature. An ultrasensitivity value of 34.98 nm/mg/mL and a detection limit of 0.00057 mg/mL were obtained. These values were more than twice those obtained using the bare sensor. The temperature sensitivity was -0.41 nm/°C. The device had inverse spectral responses to BOD concentration and temperature. For this reason, we achieved temperature compensation by demodulating the shifts in the various transmission dips. As the proposed microfiber sensor is ultrasensitive and has temperature compensation, it is a novel and promising design for biosensing and environmental pollution monitoring.
In structural simulation and design, an accurate computational model directly determines the effectiveness of performance evaluation. To establish a high-fidelity dynamic model of a complex assembled ...structure, a Hierarchical Model Updating Strategy (HMUS) is developed for Finite Element (FE) model updating with regard to uncorrelated modes. The principle of HMUS is first elaborated by integrating hierarchical modeling concept, model updating technology with proper uncorrelated mode treatment, and parametric modeling. In the developed strategy, the correct correlated mode pairs amongst the uncorrelated modes are identified by an error minimization procedure. The proposed updating technique is validated by the dynamic FE model updating of a simple fixed–fixed beam. The proposed HMUS is then applied to the FE model updating of an aeroengine stator system (casings) to demonstrate its effectiveness. Our studies reveal that (A) parametric modeling technique is able to build an efficient equivalent model by simplifying complex structure in geometry while ensuring the consistency of mechanical characteristics; (B) the developed model updating technique efficiently processes the uncorrelated modes and precisely identifies correct Correlated Mode Pairs (CMPs) between FE model and experiment; (C) the proposed HMUS is accurate and efficient in the FE model updating of complex assembled structures such as aeroengine casings with large-scale model, complex geometry, high-nonlinearity and numerous parameters; (D) it is appropriate to update a complex structural FE model parameterized. The efforts of this study provide an efficient updating strategy for the dynamic model updating of complex assembled structures with experimental test data, which is promising to promote the precision and feasibility of simulation-based design optimization and performance evaluation of complex structures.
A high-sensitivity interferometric optical microfiber sensor based on liquid cladding is proposed to detect liquid samples temperatures in special environments. The sensor is manufactured by arc ...discharge and flame-brushing technology and is encapsulated in a capillary tube and covered with deionized water. The sensor is more susceptible to the influence of the external environment due to the strong evanescent field on the tapered fiber surface. High-sensitivity measurement near room temperature is important, which can be used for effective diagnosis and treatment of local temperature of biological tissues in the field of biosensing. Compared with the silica material, the sensor based on liquid encapsulation has a larger thermo-optical coefficient, and the difference between the thermo-optic coefficient of water and the optical fiber is greater. The results show that with increasing ambient temperature, the wavelength of the transmission spectrum shifts towards shorter wavelengths. The device without liquid packaging has a temperature sensitivity of −57 pm/°C, and the liquid-encapsulated microfiber can reach −415 pm/°C ranging from 30-50 °C, which is 7 + times higher than the former. In addition to improving the temperature sensitivity of the sensor, the water cladding can protect the microfiber from damage. This sensor can be used as a basic sensing unit in remote and intelligent optical fiber sensor networks with great application potential in marine environment monitoring, biomedicine diagnosis and chemical reaction research.
Because of the randomness of many impact factors influencing the dynamic assembly relationship of complex machinery, the reliability analysis of dynamic assembly relationship needs to be accomplished ...considering the randomness from a probabilistic perspective. To improve the accuracy and efficiency of dynamic assembly relationship reliability analysis, the mechanical dynamic assembly reliability（MDAR） theory and a distributed collaborative response surface method（DCRSM） are proposed. The mathematic model of DCRSM is established based on the quadratic response surface function, and verified by the assembly relationship reliability analysis of aeroengine high pressure turbine（HPT） blade-tip radial running clearance（BTRRC）. Through the comparison of the DCRSM, traditional response surface method（RSM） and Monte Carlo Method（MCM）, the results show that the DCRSM is not able to accomplish the computational task which is impossible for the other methods when the number of simulation is more than 100 000 times, but also the computational precision for the DCRSM is basically consistent with the MCM and improved by 0.40-4.63% to the RSM, furthermore, the computational efficiency of DCRSM is up to about 188 times of the MCM and 55 times of the RSM under 10000 times simulations. The DCRSM is demonstrated to be a feasible and effective approach for markedly improving the computational efficiency and accuracy of MDAR analysis. Thus, the proposed research provides the promising theory and method for the MDAR design and optimization, and opens a novel research direction of probabilistic analysis for developing the high-performance and high-reliability of aeroengine.
Plantar pressure force data derived from gait and posture are commonly used as health indicators for foot diagnosis, injury prevention, and rehabilitation. This study developed a wearable plantar ...pressure force measurement and analysis (WPPFMA) system based on a flexible sensor matrix film to monitor plantar pressure force in real time. The developed system comprised a flexible sensor matrix film embedded in the insole of the shoe, a wearable data acquisition (DAQ) device with a Bluetooth module, and dedicated software with an intuitive graphical user interface for displaying the plantar pressure force data from receivers by using a terminal unit (laptop or smart-phone). The flexible sensor matrix film integrated 16 piezoresistive cell sensors to detect pressure force at different anatomical zones of the plantar and under different body positions. The signals from the flexible sensor matrix film were collected using the DAQ module embedded in the shoe and transmitted to the receivers through Bluetooth. The real-time display and analysis software can monitor, visualize, and record the detailed plantar pressure force data, such as average pressure force, maximum pressure force, and pressure force distributions and variations over time. The outcomes of the trials in which the system was worn revealed the applicability of the developed WPPFMA system for monitoring plantar pressure force under static and dynamic wearing conditions. The plantar pressure force data derived from this system provide valuable insights for personal foot care, gait analysis, and clinical diagnosis.
Intermittent pneumatic compression (IPC) is a proactive compression therapeutic technique in the prophylaxis of deep vein thrombosis, reduction of limb edema, and treatment of chronic venous ulcers. ...To appropriately detect and analyze biomechanical pressure profiles delivered by IPC in treatment, a dynamic interface pressure monitoring system was developed to visualize and quantify morphological pressure mapping in the spatial and temporal domains in real time. The system comprises matrix soft sensors, a smart IPC device, a monitoring and analysis software, and a display unit. The developed soft sensor fabricated by an advanced screen printing technology was used to detect intermitted pressure by an IPC device. The pneumatic pressure signals inside the bladders of the IPC were also transiently collected by a data acquisition system and then transmitted to the computer through Bluetooth. The experimental results reveal that the developed pressure monitoring system can perform the real-time detection of dynamic pressures by IPC and display the morphological pressure mapping multi-dimensionally. This new system provides a novel modality to assist in the effective evaluation of proactive compression therapy in practice. The study results contribute to understanding the working mechanisms of IPC and improving its functional design based on intuitive biomechanical characteristics of compression delivery profiles.
A structure-modulated ultralong-period microfiber grating (SULPMG) was successfully designed for simultaneous measurement of microdisplacement and temperature. The SULPMG was fabricated based on the ...standard single-mode fiber using the arc discharge method followed by hydrogenoxygen flame drawing technology. The resonance wavelength of the two notches shifts toward a shorter range when the microdisplacement varies from 0 μm to 65 μm. The results show that the wavelength sensitivity could reach a maximum value of -288.9 pm/μm with a total depth change of 2.95 dB and a high resolution of 69 nm. The temperature sensitivity of the proposed sensor could reach approximately -26.4 pm/°C over an ambient temperature range of 22-90 °C. The proposed sensor can be expected to be applied in fields pertaining to microfabrication and many industrial applications.
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