bluuebunny/crossref_metadata_2025_split huggingface dataset:
The CFD Investigation of General FPSO Green Water
Authors: Li Min , Dou Peilin , Qi Yue 
Published: March 2023

Abstract
The main research is to investigate the seakeeping effect resulting from general FPSO hull bow flare. CFD-FV (Computational Fluid Dynamics-Finite Volume) method is applied with fluent software to simulate in the 3D time domain. Simulation objects are two different bow flare models exposed to the green water phenomenon, which is under the sea state of the Brazilian sea 20 years of return extreme sea state. Seakeeping analysis includes green water. The results indicated that a 3.5 m vertical bow flare would reduce about 35.09% level of green water on deck. A comprehensive comparison indicated that bow flare improved the global seakeeping performance, which can be used as a reference to the design of general FPSO hull bow flare.
Design and Realization of Ultra-wideband Constant Beamwidth Beamforming in a Waveguide Environment
Authors: Li Xuegang , Zhu Jie , Jiang Guoqing , Hua Runan , Yao Wuping 
Published: March 2023

Abstract
Array signal processing technology has been widely used in signal detection and underwater target radiation noise measurement. A design and realization method of an ultra-wideband and high-robustness constant beamwidth beamformer based on a vertical nested array is proposed. Using the nested array multiplexing, the ultra-wideband constant beamwidth beamforming was realized by using fewer array elements; the main lobe of each sub-band beam in the designed band was made to approach the desired constraint value based on the convex optimization method; the beamforming robustness and array gain were improved through the constraint of the weight vector two-norm. In the paper, the influence on beamforming due to inconsistent array element amplitude-phases in a measured waveguide environment is analyzed. The computer simulation was used to realize the measurement of constant beamwidth beamforming within a 100-octave band range in the measured waveguide environment and verify the effectiveness of the proposed method.
A Low-Frequency Unidirectional Underwater Acoustic Transducer
Authors: Wang Qiumu , Lan Yu 
Published: March 2023

Abstract
A unidirectional underwater acoustic transducer has the advantage of narrower beam width. In the low-frequency field, a single transducer is usually omnidirectional because its dimension is much smaller than the wavelength of the sound waves. Here, a low-frequency unidirectional underwater acoustic transducer, the Single-Sided Radiation Flextensional Transducer (SSR FT), which is driven by a stack with the longitudinal vibration, was designed by the finite-element method. The vibration mode of the transducer was first studied and analyzed. Then, an underwater harmonic response analysis of the transducer was conducted. We found that the second resonance, corresponding to the fourth vibration mode, could be unidirectional based on a specific s
br, which is the ratio of r
b (the radius of the tail mass) to l
maj (the inner length of the semi-major axis of the radiation surface). Finally, the effect of s
br on the vibration velocity and directivity of the SSR FT was investigated. We established that the vibration velocity amplitude and phase of the shell were different at the same vibration mode but at different s
br, which resulted in different directivity.
An Analytical Method of Beamwidth under Different Angles of Planar Array
Authors: Kong Qiang , Zhu Jieqi , Su Peilin 
Published: March 2023

Abstract
It is widely recognized that the calculation of the beam width of the large-aperture planar array through beam pattern simulation is slow and inefficient, and obtaining the ability to distinguish the target from different angles within the observation range quickly is difficult. This paper uses methods such as the array product theorem, discrete array, continuous array beam width equivalence, and coordinate transformation to acquire a more accurate analytical solution of the beam width of the planar array. The analytical value of the beam width of the planar array at different angles and the number of array elements were compared with the simulated value. The results show that with the usage of the new method, the average deviation of the beam width analytical values in different main maxima directions can reach less than 1% when the number of array elements is less than 10 elements. Compared with the simulation method, the planar array beam width can be obtained quickly and accurately by the new method.
The Correlation between the Numerical Analysis of Wake Dynamics and the General Theory of Aerodynamic Instability of a Flapping Foil
Authors: Sun Liping , Zhou Peijian , Bao Yixiang 
Published: March 2023

Abstract
We study the correlation between the wake dynamics analyzed by numerical simulation and the general theory of aerodynamic instability of a flapping foil. The pure pitching motion and the pure heaving motion are considered in this paper. The main parameter is the Reynolds number, here we fixed the Reynolds number at Re = 1700. We found an interesting phenomenon in our research, which is that the lift amplitude CY of the numerical simulation is consistent with the the results of the general theory of aerodynamic instability, even at low frequencies where the additional mass effect is less important. And the average thrust CT(mean) increases exponentially with the Strouhal number SRA = fA/U, which is also an interesting phenomenon. By making the lift amplitude CY dimensionless with the amplitude θ0 and h
0, we find that the dimensionless lift amplitudes CY/θ0 or CY/h
0 are distributed along the same trend under different amplitudes. Through comparison and analysis of the pure pitching motion and the pure heaving motion, We clearly found that the lift on the heaving foil is slightly lower and the change of the lift is slightly more dramatic when the frequency is small.
A Combined Passive Automatic Detection Method of Constant False Alarms and Multiple Nodes
Authors: Huang Di , Zhu Xian , Gong Yi , Chen Fuhu 
Published: March 2023

Abstract
Aiming at the problem of whether multi-array passive joint detection can improve the detection performance of sonar, this paper analyzes in detail the relationship between the detection probability, false alarm probability, the input signal-to-noise ratio, and integration time under the condition of single array detection, and then obtains the input signal-to-noise ratio and integration time required to achieve the same detection probability and false alarm probability under different joint detection rules. It is concluded that the multi-array joint detection can reduce the required input signal-to-noise ratio and integration time and provide detection performance, which is verified by simulation experiments.
Study on Characteristics of Particle Dynamics with Coarse Particles in Vertical and Inclined Pipeline
Authors: Ren Wanlong , Zhang Xuhui , Zhang Yan , Lu Xiaobing 
Published: March 2023

Abstract
The pipeline hydraulic transport is an important component of the deep-sea mineral resources. The characteristics of particle dynamics with coarse particles is investigated by using the CFD-DEM method in the vertical and inclined pipeline. The normal pipeline and abnormal pipeline mentioned in this paper refer to vertical pipeline and inclined pipeline, respectively. The particles of the normal pipeline mainly move in the middle of the pipeline, while the particles mainly concentrate on the pipeline wall in the abnormal pipeline. The velocity difference of the abnormal pipeline between liquid and particle is much greater, which can be prone to cause particle aggregation. Finally, the pipeline to be blocked can be easy to be caused by the particle aggregation in the wall of abnormal pipeline. An appropriate increase in liquid velocity can improve the phenomenon.
Experimental research on sound quality evaluation of aircraft cabin
Authors: Li Hongnian 
Published: March 2023

Abstract
This paper proposes a construction method for the sound quality evaluation model of the aircraft cabin. By combining the subjective with the objective method, the relationship between the subjective results and the psychoacoustic parameters is established, and the sound quality evaluation model of the sound field in the passenger cabin is formed. The model takes the characteristic acoustic parameters that are more sensitive to the human ear, such as loudness and sharpness, as input, which can efficiently obtain the subjective result of sound quality and accurately reflect the subjective quality feeling of human ear on the current sound field.
Numerical Simulation of Thermal Conductivity of Graphene Reinforced Aluminum Matrix Composites
Authors: Wang Yan , Du Xiaoming , Chi Qingbo 
Published: March 2023

Abstract
In order to develop materials with high thermal conductivity, aluminum matrix composites are attracting much attention. The heat transfer ability of graphene-reinforced aluminum matrix composites was numerically simulated with the finite element method. A composite model of 3D many-particle stochastic distributions is developed. The effect of temperature, volume fraction of graphene, graphene shapes and graphene orientation heat transfer capacity of composite materials was researched. Studies have shown that that the graphene volume fraction, graphene shapes and graphene orientation were significant factors for the heat transfer of the composites. As the graphene content increases, the temperature transfer capacity of the composite increases. The disc-shaped graphene with an orientation angle of 45° in composites can obtain an enhancement in the heat transfer ability of the composites.
An Investigation on the Compatibility of Epoxy Resin and Asphalt Based on Molecular Simulation
Authors: Ji Xue , Gao Lei , Zhang Ye , Gao Junqi 
Published: March 2023

Abstract
Epoxy resin and asphalt compatibility have a significant impact on the material qualities of epoxy-modified asphalt. At present, there is a shortage of the study on the compatibility mechanism from the standpoint of nano. This paper evaluated the influence of temperature on the compatibility of epoxy resin (ER) and asphalt using the molecular dynamics (MD) simulation approach to explore the compatibility between ER and asphalt in greater detail. First, a twelve-component molecular model of asphalt was built, as well as a model of the system following cross-linking of epoxy resin and curing agent. And model optimization and model validation were performed. Secondly, the model of ER and asphalt co-blended system was constructed by combining the optimized model with the Amorphous Cell module. Then, MD simulations were done at various temperatures to derive the solubility parameters and intermolecular interaction energy of the mixed system for each system. Finally, the compatibility of ER with asphalt at different temperatures was analyzed based on the calculation results. It was found that the compatibility of ER and asphalt was temperature dependent. As the temperature increased, the solubility parameters of ER and asphalt decreased, and the difference in solubility parameters Δδ between them took the minimum value at 170 °C. As the temperature rises, so does the total potential energy in each system, and the intermolecular interaction energy of ER and asphalt mixed system achieves the maximum value at 170 °C. Currently, the structure of ER and asphalt mixed system is the most stable, and the compatibility between the two is the best.
Design and Analysis of Extruder Head Flow Channel of Cladding Infiltration Irrigation Pipe
Authors: Shi Changyu , Lv Bing , Wang Wenshu , Ma Yuanzheng 
Published: March 2023

Abstract
To solve the problem of deformation and to drop off buried infiltration irrigation pipe, a kind of extruder co-extrusion die that can effectively produce clad infiltration irrigation pipe is proposed from the structure and production infiltration irrigation pipe. Through the innovative design method, the flow passage and some parts of the extruder head were designed. The model of the extruder head runner was established, and the structure of the extruder head runner was optimized by finite element analysis. Compared with the original coextrusion die, this design reduces the size of the extruder die, and can effectively enhance the plasticizing effect and uniformity, and the material flow is more stable. This method is conducive to strengthening the strength and quality of the subsurface irrigation pipe, prolonging its service life, and reducing the difficulty of maintenance and replacement of the buried subsurface irrigation pipe.
Simulation on High Strain Rate Thermal Deformation Constitutive Equation of AZ91 Magnesium Alloy
Authors: He Zhongtao , Xu Chun 
Published: March 2023

Abstract
The hot compression simulation experiment of AZ91 magnesium alloy was carried out by a Gleeble-1500D thermal simulation machine under the conditions of T within the range of 300~400°C,

ε
˙

within the range of 10-2~101 s−1, and a compression capacity being 70%. In order to establish the constitutive equation more accurately, this paper uses the piecewise function model to match the σ-ε curve as the necessity of making the simulated curve have a good match with the true stress-strain curve. The linear function and nonlinear function are used to match the σ-ε curve when the material reaches the stage of softening. The fitting results show that the piecewise function matches the true stress-strain curve well under different experimental circumstances of T and

ε
˙

even at a high strain rate. This indicates that the piecewise function has a better capacity in the real situation of the relationship between hot-working deformation and the stress-strain curve of magnesium alloys.
Effect of Cryogenic Cooling on Mechanical Properties and Cutting Force of 6061 Aluminum Alloy
Authors: Wang Jinhui , Duan Pengfei , Wang Tianzhong , Wang Xiangyu , Qiao Yang 
Published: March 2023

Abstract
With the increasingly strict environmental protection requirements, cryogenic cutting technology as an environmentally friendly machining technology has received more and more attention. In this article, the affect of cryogenic cooling on the mechanical behaviors, cutting force and swarf shape of 6061 Aluminum Alloy were studied. Test result display that cryogenic increase strength of materials and reduces the plasticity of the material. Cryogenic cooling improves the cutting force and improves the chip breaking effect.
Study on matching layer of ultrasonic transducer for defect detection of stainless steel
Authors: Liu Luyu , Hou Huaishu , Wang Zongren 
Published: March 2023

Abstract
To solve the impedance mismatch problem between the piezoelectric wafer and the tested material when ultrasonic testing is used to detect the internal defects of materials, alumina powder and epoxy resin are compounded to prepare the matching layer material. Then the matching layer of the ultrasonic transducer is designed according to the quarter wavelength theory. The pulse-echo signal of the developed matching layer is tested and analyzed. The results show that the sound velocity of the matching layer is consistent with the changing trend of the acoustic impedance. That is, the acoustic impedance increases with the increase of the alumina mass fraction, and the density is 1080.73kg/m³. The ultrasonic transducer was designed by matching layer with a sound velocity of 1059.49m/s, with an acoustic impedance of 1.14mryal and acoustic attenuation coefficient of 0.1279dB/mm has good bandwidth and sensitivity.
The Effect of Heating and Cooling Process During Quenching treatment on Microstructures and Properties of Wear-Resistant Steel NM450
Authors: Ji WenBo , Lin TianZi , Zuo YuJian , Zhang Tao , Tian HongXin , Wang Yong , Wang YingShuo 
Published: March 2023

Abstract
Quenching is a conventional production process of wear-resistant steel, which has a decisive effect on the properties of wear-resistant steel. In this paper, the effects of quenching treatment on microstructures and mechanical properties of NM450 wear-resistant steel were investigated by optical microscopy and scanning electric microscopy. The results show that during the process of heating temperature of 880 °C and air cooling to 850 °C before quenching, the ductility and toughness of NM450 were improved significantly, whose comprehensive properties are better than 880 °C or 850 °C direct quenching steel. With the proportion of ferrite increasing, the strength of NM450 decreases, but the toughness doesn`t increase as influenced by grain size and grain boundary segregation. The martensite of intercritical quenching NM450 appears a shape massive, not lath.
Study on Cold Hardening and Recrystallization Temperature of Cu-Ni-Sn-P Alloy for Integrated Circuit Lead Frame
Authors: Yuan Hefeng , Yang Qi , Chen Jiacheng , Tao Jie 
Published: March 2023

Abstract
The work hardening curve of the Cu-Ni-Sn-P alloy for the integrated circuit lead frame was drawn by different degrees of cold deformation. The recrystallization temperature of the alloy was determined by testing the tensile strength, Vickers hardness, elongation, and electrical conductivity of the samples annealed at different temperatures and microstructure observation. The results show that the Cu-Ni-Sn-P alloy had obvious work hardening characteristics after being deformed by cold rolling; the tensile strength of the alloy showed a trend of first increasing and then tending to be stable with the increase of the working rate, while the elongation and electrical conductivity showed the opposite changing law. At the same annealing time, with the increase of annealing temperature, the tensile strength of Cu-Ni-Sn-P alloy decreased slowly first and then sharply, and finally tended to be stable. To effectively reduce energy consumption and shorten the production cycle, the reasonable recrystallization annealing system of Cu-Ni-Sn-P alloy after 60% deformation is determined to be 440°C×4h.
Design of calculation model of residual stress in austenitic stainless steel during plastic deformation
Authors: Deng Xiaoting , Zhang Shihong , Cheng Ming 
Published: March 2023

Abstract
In the process of processing, the residual stress in the deformed component will play a crucial role in the assembly and future use. This paper analyzes the deformation behavior of martensite phase transition induced by deformation through unidirectional stretching. The martensite phase variables and residual stress distributions after stretching were measured. The calculation model of residual stress distribution is established considering the phase change factors. It provides a theoretical basis for the calculation of phase transition behavior and residual stress distribution in the complex deformation process. A dynamic model based on stress and strain was established under different conditions, and the realization of martensite transformation was added to the finite element software with the help of secondary development subroutine. By comparing with the test data, the results show that the distribution pattern of residual stress can better reflect the residual stress after deformation under the consideration of the phase transformation of martensite.
Effects of surface roughness on fatigue behavior of additively manufactured stainless steel 316L
Authors: Zeng Guowei , Ye Wanrong , Liu Lei 
Published: March 2023

Abstract
Surface roughness plays an important role which affects the fatigue performance of additively manufactured metal components. Surface roughness generally contains micro-notches which form stress concentration and significantly deteriorate the fatigue life. Based on nonlinear elastoplasticity finite element (FE) analyses, the roughness model of additively manufactured stainless steel 316L (SS316L) was performed, and the cyclic behavior of surface notch root material under different fatigue stress loads was captured. The stress concentration factor on the selected critical surface position is calculated and the notch root strain analysis are proved by depending on the applied load level. Finally two distinct deformation modes are found: elastic shakedown and ratcheting deformation.
Study on the high-temperature corrosion behavior of 316Ti austenitic stainless steel for lead-bismuth cooled fast reactor application
Authors: Yuan Ganfeng , Sun Yulin , Wang Da , Ma Xianfeng , Zeng Jun , Liang Yuqiang , Ye Huanmin , Liu Sirui , Xiao Changquan , Hu Yanying 
Published: March 2023

Abstract
The austenitic stainless steel 316Ti with the addition of titanium is a promising candidate for fuel cladding due to its excellent corrosion resistance performance in LBE. In this paper, the corrosion behaviour of 316Ti steel in the static Lead-Bismuth Eutectic (LBE) for 1000 h at 550 °C is studied. The surface and cross-section morphologies of samples after corrosion were examined using Scanning Electron Microscope, Energy-Dispersive X-ray Spectroscopy and X-ray Diffraction. It concluded that the 316Ti undergoes both oxidations accompanied by the formation of a double-layer oxides and elements leaching that resulted in the nonuniform distribution of Cr, Ni, and Fe near the matrix/LBE interfac. The external oxide film mostly consisted by Fe3O4, and the internal oxide layer is primarily Fe-Cr spinel.
Design of Control System for Cultural Relics Testing Room Based on STM32
Authors: Huang Yangyang , Cui Ming , Li Bangyu 
Published: March 2023

Abstract
This paper designs a control system for a cultural relic test chamber based on STM32. The system uses the STM32 processor as the underlying main control of oxygen concentration and humidity and uses an industrial all-in-one machine as the bridge to exchange the information between the cloud server and the bottom master controller. The oxygen concentration, humidity and temperature data of the test chamber can be stored on the server in real-time, and the alarm messages are sent through the cloud SMS platform. The results reveal that the oxygen concentration in the test chamber could be adjusted continuously between 0.6% ~ 10% VOL and the relative humidity could be adjusted continuously within 45% ~ 55% RH, and it can keep stable near the set value. The system can meet the requirements of oxygen concentration and humidity for most cultural relics preservation and can also provide a settable constant oxygen concentration and humidity environment for the related research of anoxic treatment and modified atmosphere technology.
Analysis of Pressure Impact Characteristics of a Hydraulic Position Servo System Based on Series Servo Valves
Authors: Mao Xuyao , Xiang Chao , Hu Juhua , Wu Zhengjiang , Zeng Baoping 
Published: March 2023

Abstract
As one of the causes of system vibration and noise, pressure impact is always undesired. Analysis of pressure impact characteristics of a hydraulic position servo system based on a two-stage series servo valve is carried out to reduce the system impact. The influence of factors such as system flow rate, additional servo valve opening gain, external load, and system overflow pressure on the system pressure impact is analyzed. The results show that the series servo valve scheme can bring down the peak impact pressure at the inlet of the hydraulic cylinder by 8%~11% when the system flow rate or overflow pressure is low to a certain extent. In most other cases, the suppression effect of the impact peak pressure is unapparent. The impact pressure overshoot is always decreased accompanied by an easier trend to overflow for the system. At last, another new idea of application promotion with higher reliability and adaptability is proposed.