EMCS-SVR: Hybrid efficient and accurate enhanced simulation approach coupled with adaptive SVR for structural reliability analysis

Fatigue life prediction based on a deep learning method for Ti-6Al-4V fabricated by laser powder bed fusion up to very-high-cycle fatigue regime

A novel defect-based fatigue damage model coupled with an optimized neural network for high-cycle fatigue analysis of casting alloys with surface defect

Investigation of the strength of concrete-like material with waste rock and aeolian sand as aggregate by machine learning

Laser additive manufacturing (AM) is an advanced green shaping technology that enables fast and flexible fabrication or repair of high-performance metallic materials. Since the component with the complex structure can be directly shaped by AM technologies, and then it can not only achieve the increase of the production efficiency of the AM component, but also the reduction of the component weight. Therefore, AM technologies are extensively used in the aerospace and automotive industries. Moreover, since AM components are usually in service under the conditions of static or complex dynamic cyclic loading, the fatigue performance of AM components is a key consideration during the service process. However, during the additive manufacturing process, the intrinsic AM defects such as lack of fusion (LOF) and unmelted particles will inevitably be formed, causing the stress concentration in the local area of the AM component, thus deteriorating the fatigue performance of the AM component. At the same time, since the defects in AM component can be reduced by the post-treatments or heat treatments but may not be fully eliminated, and therefore, the presence of the intrinsic AM defects tends to lead to unstable fatigue properties of the AM components compared with the components prepared by conventional manufacturing technologies. This work mainly reviews the latest research progress in improving the fatigue properties of superalloys manufactured by laser directed energy deposition (L-DED) and laser powder bed fusion (L-PBF) techniques. The research results of AM titanium alloys, nickel-based alloys and iron-based alloys in this field are highlighted, and the low-cycle fatigue, high-cycle fatigue behaviors and fatigue crack propagation processes of these alloys under multi-field coupling and general testing conditions are compared and reviewed. In addition, this review also analyzes the effects of defects, microstructures, and printing processes, post-treatments, and heat treatments on the fatigue properties of the AM superalloys, and also introduces the relevant fatigue mechanical models, and provides an outlook for important future development directions in this research field. 

Multi-field coupling fatigue behavior of laser additively manufactured metallic materials: A review

A Fatigue Life Prediction Approach for Laser-Directed Energy Deposition Titanium Alloys by Using Support Vector Regression Based on Pore-Induced Failures

The effect of porosity defects on the mid-cycle fatigue behavior of directed energy deposited Ti-6Al-4V

2-3 μm mid-infrared luminescence of Ho3+/Yb3+ co-doped chloride-modified fluorotellurite glass.

The thermal stability and structural evolution of (55-x-y)Al(PO3)3-xNaF-8MgF2-10CaF2-ySrF2-17BaF2-10LiF (mol%) glasses were investigated. The thermal stability of the fluorophosphate glass system was characterized by DSC. As the content of metaphosphate increased, the thermal stability was strengthened. Besides, the thermal stability reached the strongest at alkaline metal and alkaline earth metal fluoride contents converged. On the one hand, according to Raman and FT-IR spectra, it was demonstrated that the intensity of OPO vibration in the glass structure was strengthened with the increase of Al (PO3)3 and NaF. On the other hand, 31P NMR results indicated that the POP bond was also enhancing when the Al (PO3)3 content increased. In summary, OPO and POP bonds were components of [PO4] units, and their increase signified that the structural stability of glass was enhanced. During the process of expanding the content of Al(PO3)3, deconvolution of O 1s and F 1s in XPS spectrum revealed that the increase of PO and FP bond content resulted in the structural distortion of polyhedral P[O, F]4 in glass structure and enhanced the disorder of glass. 

Effect of Al(PO3)3, NaF, and SrF2 on structure and properties of fluorophosphate glass

GNSS-R is a new branch of GNSS which has been developed since the 1990s. It can be applied to remote sensing exploration of marine environment and remote sensing of terrestrial environment. GNSS-R has many advantages over other remote sensing techniques, such as remote sensing, Low cost, low power consumption, high spatial and temporal resolution, and many other advantages of the project can be detected. GNSS-R marine remote sensing detection technology mainly through high-gain reflection antenna to receive the GNSS reflection signal from the sea to complete the marine environmental detection, the reflected signal carries changes in signal waveforms, changes in polarization characteristics, amplitude, phase, and frequency. In this paper, a GNSS-R ocean height detection technique based on carrier phase assistant was introduced. The conventional channel accomplishes the initial acquisition of the signal and outputs the original DDM pattern by the time delay-Doppler mapping correlator, DDM diagram can be used to complete the inversion of the wind field, etc., while the DDM map contains the reflected signal doppler, time delay information, the accuracy of doppler and time delay was determined by the DDM Doppler interval and the time interval. The processor can process the time delay of the reflected signal to obtain a roughly phase and doppler information. The closed-loop acquisition and tracking of the signal was completed by the time information and doppler information obtained by the reflection. By calculating the direct and reflection channel carrier phase, pseudo-range difference for the sea surface height inversion. In order to verify the inversion accuracy of the system, in this paper, the ground-based test and flight test was carried out using the self-research phased-array GNSS-R ocean reflection receiver system. The experimental data showed that the inversion error of sea surface height was better than 10 cm.

Dingcheng Tang

Papers

A Fatigue Life Prediction Approach for Laser-Directed Energy Deposition Titanium Alloys by Using Support Vector Regression Based on Pore-Induced Failures

The effect of porosity defects on the mid-cycle fatigue behavior of directed energy deposited Ti-6Al-4V

2-3 μm mid-infrared luminescence of Ho3+/Yb3+ co-doped chloride-modified fluorotellurite glass.

Effect of Al(PO3)3, NaF, and SrF2 on structure and properties of fluorophosphate glass

GNSS-R Ocean Altitude Detection Technology Based on Carrier Phase Assistant