Reduction Zone Era (RZera), a customized and user-friendly software designed for the reduction of time-of-flight (TOF) data from the Multi-physics Instrument (MPI) at China Spallation Neutron Source ...(CSNS), is developed and presented in this paper. After inputting the required information, the software can transform and apply a series of corrections from raw data to user data that only reflects the intrinsic properties of the sample. The software has two modes: diffraction and pair distribution function reduction. Each mode is capable of processing batch data quickly. The nickel has been used to test the diffraction and the pair distribution function reduction mode separately. The diffraction result has been fitted by GSAS, and the pair distribution function result has been fitted by the DiffPy-CMI suite. All the fittings demonstrate the effectiveness of RZera. The future versions of RZera will integrate additional instrument data reduction capabilities, and incorporate advanced algorithms and features that address emerging challenges in neutron scattering research.
•Loading deviations are quantified by displacement gauges data in real time.•Strain field based on digital twin (DT) is built by strain and displacement data.•DT can combine all the advantages of ...multi-type data of FEA and sensor data.•Considering real-time loading deviations is helpful to improve the accuracy of DT.
For the static loading test, digital twin (DT) constructed by multi-type data fusion can combine the advantages of these data, which has potential application in test monitoring. Affected by assembly and manufacturing defects of test system, the loading deviations are difficult to avoid and quantify, and it has an important effect on the strain state of structures. However, the current DT is built by data fusion of strain gauges data and strain field of finite element analysis (FEA) only, and how to build DT considering real-time loading deviations by fusing multi-type sensor data remains a challenging task. Therefore, a strain field reconstruction method based on DT considering the real-time loading deviations (DT-SFRM-LD) is proposed to improve the accuracy of DT. In the test, the loading deviations calculated by displacement sensors data are used as FEA database input to obtain FEA strain field considering real-time loading deviations. The FEA strain field is combined with strain gauges data to construct DT in real time, which combines all the multi-type data advantages of displacement gauges, FEA strain field and strain gauges. A cylindrical shell test is performed to validate the high accuracy of DT-SFRM-LD. Results indicate that the AvgErr (5.0%) and MaxErr (13.6%) of DT-SFRM-LD are 4.3% and 10.0% lower than those of conventional DT method, and the AvgErr of DT-SFRM-LD is less affected by the eccentricity distance. In general, under different test conditions, the accuracy of DT-SFRM-LD is always higher than that of conventional DT method, indicating that considering the real-time loading deviations by displacement gauges is helpful to provide accurate FEA strain field distribution and to improve the accuracy of DT-SFRM-LD.
•A homogenization-based model updating approach for the grid stiffened cylindrical shell is proposed.•The axially compressed buckling test of a 1.6-m-diameter orthogrid stiffened cylindrical shell is ...performed.•The error of the high-fidelity updated finite element model is only −0.67% compared with the experimental result.
Stiffened cylindrical shells are commonly used in the launch vehicle, which are prone to buckling under axial compression load and extremely sensitive to imperfections. Establishing a high-fidelity finite element model is a prerequisite for correctly analyzing buckling load and imperfection sensitivity of stiffened cylindrical shells. This paper proposes a homogenization-based model updating approach for the grid stiffened cylindrical shell with many chamfers, which can establish a high-fidelity shell finite element model that maintains calculation efficiency and accuracy advantages. It uses the equivalent elastic constants of the unit cell as the link to modify the size parameters of the finite element model for the grid stiffened cylindrical shell. Moreover, the axially compressed buckling test of a 1.6-m-diameter orthogrid stiffened cylindrical shell is performed to verify the effectiveness of the proposed method. Through comparison, it could be found that the updated finite element model has a higher analysis accuracy. Specifically, the analysis error of the initial finite element model is −16.85% compared with the test result, while the error of the updated model is only −0.67%. The updated model can be used with full confidence for simulating mechanical performance such as the buckling process and the imperfection sensitivity analysis. Besides, it also indicates the necessity of considering the structural characteristics such as the chamfer in the optimization design process of the grid stiffened cylindrical shell structure.
The high reflectivity and excellent thermal conductivity exhibited by copper substrates pose considerable challenges for conventional laser cladding techniques aiming to achieve high-performance ...coatings on their surfaces. In this study, a novel blue diode laser cladding approach was proposed to prepare nickel-based coatings on copper substrates. Under the conditions of a preheating temperature of 200 °C and laser power of 1500 W, a Ni60A coating was successfully fabricated on the surface of pure copper, with metallurgical bonding achieved and no crack defects observed. The average microhardness of the coating ranges from 468 HV0.1 to 775 HV0.1, which is approximately 8.8–14.6 times greater than that of the copper substrate. Furthermore, the wear resistance of the coating is approximately 3.6–4.7 times higher than that of copper at 25 °C, and approximately 3.8–5.4 times higher at 300 °C. The performance of the coating exhibit gradient variations in the cladding direction. Consequently, the challenges posed by the high laser reflectivity and the need for a high preheating temperature of copper substrate have been effectively overcome through the utilization of a blue laser cladding, facilitating the industrial-scale preparation of large-area coatings on copper components.
•A novel strain field reconstruction method is proposed for test monitoring.•Strain field is reconstructed by fitting coordinates and strains of strain gauges.•Real buckling regions of article are ...accurately predicted by proposed method.•Novel method is suitable for high-nonlinearity strain field reconstruction.
For the static loading test in the aerospace field, conventional strain field reconstruction based on finite element analysis (FE-SFRM) is difficult to meet the accuracy requirements of test monitoring. A novel experiment strain field reconstruction method (EXP-SFRM) is proposed to improve the accuracy and monitoring effect of reconstructed field. Firstly, the coordinates of strain gauges are introduced to build the connections in space between discrete strain gauges and make it possible to check the accuracy of finite element analysis. Next, the real-time strains with high-precision coordinates are employed to reconstruct the strain field by radial basis function. A cantilever plate test and a large opening cylindrical shell (LOCS) test are performed to validate the high accuracy and good monitoring effect of EXP-SFRM. For the LOCS test, a maximum inward and outward bending criterion (MIOBC) is also proposed to determine the buckling regions. The results show that the average errors of EXP-SFRM are 2.8% (cantilever plate) and 17.4% (LOCS), which are 4.8% and 26.4% lower than these of FE-SFRM. Additionally, for LOCS, the risk regions predicted by EXP-SFRM are finally consistent with the real buckling regions, while these predicted by FE-SFRM are not. Compared with conventional FE-SFRM, the EXP-SFRM is proved to have high accuracy and good monitoring effect during test process.
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To enhance the durability of copper tuyeres in blast furnaces, it is necessary to apply coatings on their surfaces to protect against wear caused by high-temperature coke. In this study, a series of ...in-situ synthetic TiC-reinforced Stellite 6 alloy coatings containing a Ni60A interlayer were successfully produced on copper substrates using 5–45 wt% TiFe/Cr3C2 precursor powders. The coatings exhibited excellent metallurgical bonding with the Ni60A interlayer, and an elemental transition zone was formed at the interface between the coating and the interlayer. XRD Rietveld refinement analysis revealed that the T45 coating with 45 wt% of precursor powder showed the highest TiC phase content of 12.27 %, with an average hardness of 658.15 HV0.2, which was 31.2 % higher than that of the Stellite 6 alloy. The wear mechanism of the Stellite 6 coating was plastic delamination at 25 °C, and oxidative wear at 500 °C. As the TiC particle content in the coating increased, the dominant wear mechanism tended to shift towards abrasive wear. The specific wear mechanism of the coating was influenced by the content of coating phases and the operating temperature. The best wear resistance was achieved by the T45 coating, which showed an abrasive wear mechanism at both 25 °C and 500 °C, with a wear resistance of 4.47 and 5.94 times higher than that of the Stellite 6 alloy respectively.
The stress-induced martensite transformations (SIMTs) dramatically affect the recoverable strain and mechanical response of polycrystalline NiTi. An in-depth understanding of the propagation manner ...and orientation preference of SIMTs is therefore crucial. In this work, we present a unique asymmetric anisotropy of SIMTs and lattice strains induced by Lüders-type deformation in polycrystalline NiTi, achieved through a combination of in-situ synchrotron X-ray diffraction and uniaxial tensile loading and unloading experiments. Our experimental findings reveal that in polycrystalline NiTi under uniaxial deformation, the asymmetry of SIMTs is attributed to the inhomogeneous strain field caused by the Lüders-type mechanism. The asymmetrical SIMT starts with the forward Lüder band and disappears along with the backward Lüder band. The austenite with the favored orientation of ⟨110⟩A//loading direction (LD) transformed and recovered back at a higher rate compared to other orientations during both loading and unloading.
One of the greatest challenges for long-term human activities on the Moon is the development of in-situ resource utilization (ISRU) technologies, including in-situ oxygen extraction. In this study, a ...novel method called laser thermal vacuum metallurgy (LTVM) was proposed for oxygen extraction from lunar regolith, specifically using TiO2 as raw material. Firstly, the theoretical feasibility of oxygen production from TiO2 was elucidated through thermodynamic calculations. Subsequently, the impact of laser power density on the decomposition behavior of TiO2 was investigated. The results demonstrate that through the augmentation of laser power density to elevate temperatures, there is a substantial enhancement observed in both the pyrolysis and vaporization processes of TiO2. Under the conditions of a laser power density of 2.48 kW/cm2, the surface temperature of TiO2 can be maintained at approximately 2175 °C. The resulting pyrolysis products consist of Ti6O11 (8.2 ± 0.5 wt %), Ti5O9 (23.7 ± 0.6 wt %), Ti4O7 (10.9 ± 0.4 wt %), and Ti3O5 (57.2 ± 0.8 wt %). Further combining with the result of gas collection, the estimated oxygen extraction rate is approximately 43.3 L per kilogram of TiO2. Therefore, LTVM holds the potential to provide a new approach for in-situ oxygen extraction from titanium-containing lunar regolith on the Moon.
•A novel method for in-situ oxygen extraction from TiO2 on the moon using laser thermal vacuum metallurgy was proposed.•The feasibility of oxygen production via vacuum pyrolysis of TiO2 was elucidated through thermodynamic calculations.•The vacuum pyrolysis behavior of TiO2 and its corresponding oxygen extraction were investigated and discussed.•Laser thermal vacuum metallurgy has the potential to extract ∼43.3 L of O2 per kg of TiO2.
To identify the critical factors associated with the progression-free survival (PFS) and overall survival (OS) of high-grade glioma (HGG) in adults who have received standard treatment and establish ...a novel graphical nomogram and an online dynamic nomogram.
This is a retrospective study of adult HGG patients receiving standard treatment (surgery, postoperative radiotherapy, and temozolomide (TMZ) chemotherapy) at Huashan Hospital, Fudan University between January 2017 and December 2019. We used uni- and multi-variable COX models to identify the significant prognostic factors for PFS and OS. Based on the significant predictors, graphical and online nomograms were established.
A total of 246 patients were enrolled in the study based on the inclusion criteria. The average PFS and OS were 22.99 ± 11.43 and 30.51 ± 13.73 months, respectively. According to the multi-variable COX model, age, extent of resection (EOR), and IDH mutation were associated with PFS and OS, while edema index (EI) was relevant to PFS. In addition, patients with IDH and TERT promoter co-mutations had longer PFSs and OSs, and no apparent survival benefit was found in the long-cycle TMZ adjuvant chemotherapy compared with the standard Stupp protocol. Based on these critical factors, a graphical nomogram and online nomogram were developed for predicting PFS and OS, respectively. The calibration curve showed favorable consistency between the predicted and actual survival rates. C-index and time-dependent AUC showed good discrimination abilities.
We identified the significant predictors for the PFS and OS of HGG adults receiving standard treatment and established user-friendly nomogram models to assist neurosurgeons in optimizing clinical management and treatment strategies.
