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Crack Growth Rate Model Derived from Domain Knowledge-Guided Symbolic Regression

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Chinese Journal of Mechanical Engineering 2023年第3期36卷 286-301页

作者： Shuwei Zhou Bing Yang Shoune Xiao Guangwu yang Tao Zhu State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu 610031China

Machine learning(ML)has powerful nonlinear processing and multivariate learning capabilities,so it has been widely utilised in the fatigue field.However,most ML methods are inexplicable black-box models that are difficult to apply in engineering practice.Symbolic regression(SR)is an interpretable machine learning method for determining the optimal fitting equation for datasets.In this study,domain knowledge-guided SR was used to determine a new fatigue crack growth(FCG)rate model.Three terms of the variable subtree ofΔK,R-ratio,andΔK_(th)were obtained by analysing eight traditional semi-empirical FCG rate models.Based on the FCG rate test data from other literature,the SR model was constructed using Al-7055-T7511.It was subsequently extended to other alloys(Ti-10V-2Fe-3Al,Ti-6Al-4V,Cr-Mo-V,LC9cs,Al-6013-T651,and Al-2324-T3)using multiple linear regression.Compared with the three semi-empirical FCG rate models,the SR model yielded higher prediction accuracy.This result demonstrates the potential of domain knowledge-guided SR for building the FCG rate model.

关键词： Fatigue crack growth rate Stress intensity factor range Threshold stress intensity factor range R-ratio Symbolic regression Machine learning

Method for Evaluating Bolt Competitive Failure Life Under Composite Excitation

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Chinese Journal of Mechanical Engineering 2023年第4期36卷 372-384页

作者： Guangwu yang Long yang Han Zhao Haoxu Ding Bing Yang Shoune Xiao State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China

In this study,the competitive failure mechanism of bolt loosening and fatigue is elucidated via competitive failure tests on bolts under composite excitation.Based on the competitive failure mechanism,the mode prediction model and“load ratio-life prediction curve”(ξ-N curve)of the bolt competitive failure are established.Given the poor correlation of theξ-N curve,an evaluation model of the bolt competitive failure life is proposed based on Miner’s linear damage accumulation theory.Based on the force analysis of the thread surface and simulation of the bolt connection under composite excitation,a theoretical equation of the bolt competitive failure life is established to validate the model for evaluating the bolt competitive failure life.The results reveal that the proposed model can accurately predict the competitive failure life of bolts under composite excitation,and thereby,it can provide guidance to engineering applications.

关键词： Bolt Competitive failure life Evaluation model Mode prediction model Composite excitation

Genome editing in grass plants

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aBIOTECH 2020年第1期1卷 41-57页

作者： Si Nian Char Bing Yang Division of Plant Sciences University of MissouriColumbiaMO 65211USA Donald Danforth Plant Science Center St.LouisMO 63132USA

Cereal crops including maize,rice,wheat,sorghum,barley,millet,oats and rye are the major calorie sources in our daily life and also important bioenergy sources of the world.The rapidly advancing and state-of-the-art genome-editing tools such as zinc finger nucleases,TAL effector nucleases,and clustered regularly interspaced short palindromic repeats(CRISPR)/CRISPR-associated systems(CRISPR-Cas9-,CRISPR-Cas12a-and CRISPR/Cas-derived base editors)have accelerated the functional genomics and have promising potential for precision breeding of grass crops.With the availability of annotated genomes of the major cereal crops,application of these established genome-editing toolkits to grass plants holds promise to increase the nutritional value and productivity.Furthermore,these easy-to-use and robust genome-editing toolkits have advanced the reverse genetics for discovery of novel gene functions in crop plants.In this review,we document some of important progress in development and utilization of genome-editing tool sets in grass plants.We also highlight present and future uses of genome-editing toolkits that can sustain and improve the quality of cereal grain for food consumption.

关键词： Genome editing Cereal crops ZFNs TALENs CRISPR/Cas9 CRISPR/Cas12a Base editor

Research on the Influence of Multiple Parameters on the Responses of a B-type Subway Train

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Chinese Journal of Mechanical Engineering 2022年第4期35卷 329-346页

作者： Yanwen Liu Bing Yang Shoune Xiao Tao Zhu Guangwu yang Ruixian Xiu State Key Laboratory of Traction Power Southwest Jiaotong University Basic R&D Department National Railway Passenger Car Engineering Research CenterChangchun Railway Vehicles Co.Ltd College of Engineering Changchun Normal University

To obtain improved comprehensive crashworthiness criteria for a B-type subway train, the influence laws of the vehicle design collision weight M and empty stroke D on the train’s collision responses were investigated, and multiobjective optimization and decision-making were performed to minimize TS(total compression displacement along the moving train) and TAMA(the overall mean acceleration along the moving train). Firstly, a one-dimensional train collision dynamics model was established and verified by comparing with the results of the finite element model. Secondly, based on the dynamics model, the influence laws of M and D on the collision responses, such as the energy-absorbing devices’ displacements and absorbed energy, vehicles’ velocity and acceleration, TS, TAMA and the coupling correlation effect were investigated. Then, surrogate models for TS and TAMA were developed using the optimal Latin hypercube method(OLHD) and response surface method(RSM), and multi-objective optimization was conducted using the particle swarm optimization algorithm method(MPOSO). Finally, the entropy method was used to obtain the weight coefficients for TS and TAMA, and multi-objective decision-making was performed. The results indicate that D and M significantly affect the compression displacements and energy absorption of the first three collision interfaces, but have limited impact on the last three collision interfaces. The velocity versus time curves of vehicle M1 and M2 are shifted and parallel with different D. However, the velocity versus time curves of all the vehicles are shifted but gradually divergent with different M. The maximum collision instantaneous accelerations of the vehicles are directly determined by M, but are only slightly affected by D. Under the coupling effect, all concerned collision responses are strongly correlated with M; however, the responses are weakly correlated with D except for the compression displacement at the M2-M3 collision interface and the maximum collision instantaneous acceleration o

关键词： Train collision response Multi-body dynamics model Experiment design Surrogate model Multi-objective optimization Entropy method Multi-objective decision-making

On the surface brightness radial profile of the extendedγ-ray sources

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Science China(Physics,Mechanics & Astronomy) 2022年第1期65卷 84-91页

作者： Rui-Zhi yang bing Liu Department of Astronomy School of Physical SciencesUniversity of Science and Technology of ChinaHefei 230026China CAS Key Labrotory for Research in Galaxies and Cosmology University of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Key Laboratory of Modern Astronomy and Astrophysics(Nanjing University) Ministry of EducationNanjing 210093China

The morphology of the extendedγ-ray source is governed by the propagation process of parent relativistic particles.In this paper,we investigate the surface brightness radial profile of extendedγ-ray sources illuminated by cosmic ray protons and electrons,considering the radiation mechanisms,projection effects,and the response of instruments.We find that the parent particle species and the propagation process can cause considerable differences in the observed radial profiles.Thus,the surface brightness profile can be used as a unique tool to identify the radiation mechanism and the propagation process of the parent particles.In addition,we also discuss the possible implications regarding the latest discoveries from very/ultra-high energyγ-ray instruments like LHAASO and HAWC.

关键词： cosmic rays γ-ray sources diffuse emission

Parameters Calibration of the GISSMO Failure Model for SUS301L-MT

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Chinese Journal of Mechanical Engineering 2023年第1期36卷 332-343页

作者： Tao Zhu Haoxu Ding Chao Wang Yuxin Liu Shoune Xiao Guangwu yang Bing Yang State Key Laboratory of Traction Power Southwest Jiaotong UniversityChengdu610031China FAW Jiefang Automobile Co. LTDChangchun130011China

With the development of the rail transit industry,more attention has been paid to the passive safety of rail vehicles.Structural damage is one of the main failure behaviors in a rail vehicle collision,but it has been paid little attention to in past research.In this paper,the quasi-static fracture experiments of SUS301L-MT under different stress states were carried out.The mechanical fracture properties of this material were studied,and the corresponding finite element simulation accuracy was improved to guide the design of vehicle crashworthiness.Through the tests,the fracture behavior of materials with wide stress triaxiality was obtained,and each specimen’s fracture locations and fracture strains were determined.Parameters of a generalized incremental stress state dependent damage model(GISSMO)of the material were calibrated,and the model’s accuracy was verified with test results from a 45°shear specimen.The GISSMO failure model accurately reflected the fracture characteristics of the material.The mesh dependency of this model was modified and discussed.The results show that the simulation agrees well with experimental data for the force-displacement curve after correction,but the strain distribution needs to be further studied and improved.

关键词： SUS301L-MT Fracture failure GISSMO model Finite element simulation Stress state

Multimode sensing based on optical microcavities

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Frontiers of Optoelectronics 2023年第3期16卷 153-167页

作者： Yanran Wu bing Duan Changhong Li Daquan yang State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and TelecommunicationsBeijing 100876China School of Information and Communication Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China School of Electronic Information Qingdao UniversityQingdao 266071China

Optical microcavities have the ability to confne photons in small mode volumes for long periods of time,greatly enhancing light-matter interactions,and have become one of the research hotspots in international academia.In recent years,sensing applications in complex environments have inspired the development of multimode optical microcavity sensors.These multimode sensors can be used not only for multi-parameter detection but also to improve measurement precision.In this review,we introduce multimode sensing methods based on optical microcavities and present an overview of the multimode single/multi-parameter optical microcavities sensors.Expected further research activities are also put forward.

关键词： Optical microcavity Multimode sensing Multiparameter measurement Sensing mechanisms

Shear testing on rock tunnel models under constant normal stress conditions

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第6期14卷 1722-1736页

作者： Bing Yang Quan Jiang Xiating Feng Jie Xin Dingping Xu State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan430071China University of Chinese Academy of Sciences Beijing100049China Key Laboratory of Ministry of Education on Safe Mining of Deep Metal Mines Northeastern UniversityShenyang110819China

Large shear deformation problems are frequently encountered in geotechnical engineering.To expose the shear failure mechanism of rock tunnels,compression-shear tests for rock models with circular tunnel were carried out,including single tunnel and adjacent double tunnels.The failure process is recorded by the external video and miniature cameras around the tunnel,accompanied by real-time acoustic emission monitoring.The experiments indicate that the shearing processes of rock tunnel can be divided into four steps:(i)cracks appeared around tunnels,(ii)shear cracks and spalling ejection developed,(iii)floor warping occurred,and(iv)shear cracks ran through the tunnel model.Besides,the roughness of the sheared fracture surface decreased with the increase in normal stress.Corresponding numerical simulation indicates that there are tensile stress concentrations and compressive stress concentrations around the tunnel during the shearing process,while the compressive stress concentration areas are under high risk of failure and the existence of adjacent tunnels will increase the degree of stress concentration.

关键词： Circular tunnel model Compression-shear test Spalling Numerical simulation Fracture surface roughness

Volume transport in the East Taiwan Channel in response to diff erent tracks of typhoons as revealed by HYCOM data

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Journal of Oceanology and Limnology 2022年第1期40卷 22-36页

作者： Yuanshou HE Po HU Bing Yang Yuqi YIN Yijun HOU CAS Key Laboratory of Ocean Circulation and Waves Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laboratory for Ocean and Climate Dynamics Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

Northward infl ow through the East Taiwan Channel is vital in modulation of water exchange processes off northeastern Taiwan,China.In addition to the eff ects of the Kuroshio Current and westward-propagating oceanic mesoscale eddies,the seas off eastern Taiwan,China,are frequently infl uenced by typhoons.Focusing on extrema of East Taiwan Channel volume transport(ETCVT)that appear within days of typhoon infl uence,this study investigated 124 historical cyclones including 91 typhoons that passed over the study sea area off eastern Taiwan,China.Based on 25-year HYbrid Coordinate Ocean Model(HYCOM)data,71%of short-term(within 10 d)ETCVT absolute values with>5 Sv occurred under the infl uence of typhoons crossing the study sea area,and the maximum short-term ETCVT extrema induced by typhoons were 12.5 and-10.9 Sv.The ETCVT extrema induced by typhoons showed reasonable positive correlation with typhoon wind speed.More importantly,the ETCVT extrema diff ered in response to diff erent typhoon tracks.Three types of typhoon were identifi ed based on their track and impact on ETCVT.Representative typhoon cases were examined to elucidate the specifi cs of each typical response.Based on historical best track data and HYCOM data,it was established that Type I typhoons caused the ETCVT to exhibit a negative extremum followed by a positive extremum.All Type I,II,and III typhoons tended to result in typical ETCVT fl uctuations in the surface mixing layer above the depth of 50-100 m,while Type II typhoons were more likely to induce ETCVT fl uctuations in the subsurface layer.The fi ndings of this study enhance understanding of ETCVT extrema that occur following typhoon passage,which is valuable for short-term physical-biogeochemical studies both in the study region and in areas downstream owing to the large net volume transport changes induced by typhoons.

关键词： ocean modeling East Taiwan Channel volume transport extrema typhoon