西北工业大学学报最新文献_第8页

Characteristic analysis and optimization of special-shaped micro-textured multi-oil wedge sliding bearing 异形微织构多油楔滑动轴承的特性分析与优化

西北工业大学学报 Pub Date : 2023-02-01 DOI: 10.1051/jnwpu/20234110222

Y. Yu, Le Zhou, Wenxin Ruan, P. Xu, Jiaxing Shen

{"title":"Characteristic analysis and optimization of special-shaped micro-textured multi-oil wedge sliding bearing","authors":"Y. Yu, Le Zhou, Wenxin Ruan, P. Xu, Jiaxing Shen","doi":"10.1051/jnwpu/20234110222","DOIUrl":"https://doi.org/10.1051/jnwpu/20234110222","url":null,"abstract":"In order to deeply explore the potentials of micro-texture on enhancing the performances of a multi-oil wedge sliding bearing, a three-oil-wedge radial sliding bearing is taken as the prototype to simulate its bearing pressure, friction coefficient and temperature with the CFD method. According to the prototype bearing, the elliptic opening offset parabola micro texture(EOOPT) is designed. The response surface method is used to analyze the influence of EOOPT parameters on characteristics of the three-oil-wedge radial sliding bearing, and its corresponding quadratic regression equations are established. The multi-objective optimization of EOOPT parameters is carried out to obtain the optimal EOOPT parameters. The simulation results show that the sequence of influences of EOOPT parameters on the average bearing pressure and friction coefficient of the radial sliding bearing is as follows: short half axis, semi-major axis, depth, offset, texture evenly distributed angle. The sequence of influence on average temperature is depth, semi-major axis, texture evenly distributed angle, offset, short half axis. Compared with the prototype bearing, the average bearing pressure of the optimal-parameter micro-texture bearing increases by 13.7%, while the friction coefficient and average temperature decrease by 13.8% and 8.3% respectively.","PeriodicalId":39691,"journal":{"name":"西北工业大学学报","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43563872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Molecular dynamics simulation on friction performance of collision sliding contacts of soft metals in vibration environment 振动环境下软金属碰撞滑动接触摩擦性能的分子动力学模拟

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061269

Baobao Qiang, R. Tong, Jun Ye, Ze-fen Quan, Jingyan Wang, Shilin Li

{"title":"Molecular dynamics simulation on friction performance of collision sliding contacts of soft metals in vibration environment","authors":"Baobao Qiang, R. Tong, Jun Ye, Ze-fen Quan, Jingyan Wang, Shilin Li","doi":"10.1051/jnwpu/20224061269","DOIUrl":"https://doi.org/10.1051/jnwpu/20224061269","url":null,"abstract":"Soft metals are often used for space mechanism lubrication because of their low shear strength. In outer space, the vibration of spatial mechanism will occur when there is a small disturbance due to the effects of microgravity environment. Studies on the friction properties of soft metals in vibration environment could contribute to the application of space lubrication materials. Taking a clearance joint as an example, the relative motion between the shaft and the bearing is simplified to a sliding contact between a cylinder and two smooth contact bodies. A molecular dynamics model of the collision sliding contact between a rigid cylindrical indenter and an elastic substrate is established. The effects of sliding velocity, collision velocity and indenter radius on the friction properties of soft metals are studied. The results show that the Ag substrate and Au substrate present strong adhesion to the Fe indenter. The indenter and the substrate are always in a state of adhesive sliding contact. The larger the initial collision velocity of the indenter, the higher the friction force. The friction force shows great values as the sliding velocity increases. As the increase of indenter radius, the contact area is enlarged, which results in a high friction force. The adhesion of the Cu substrate to the Fe indenter is weak, so the friction force shows a low value, and the friction performance of Cu is the best, while the friction performance of Au is the worst.","PeriodicalId":39691,"journal":{"name":"西北工业大学学报","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"57899625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on main failure modes of multiple-holes structures based on branch-bound method 基于分支定界法的多孔结构主要失效模式研究

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061204

W. Xie, Yadan Zhang, Zehua Ma, Jinrong Feng, Yu Wu

{"title":"Study on main failure modes of multiple-holes structures based on branch-bound method","authors":"W. Xie, Yadan Zhang, Zehua Ma, Jinrong Feng, Yu Wu","doi":"10.1051/jnwpu/20224061204","DOIUrl":"https://doi.org/10.1051/jnwpu/20224061204","url":null,"abstract":"Aiming at the typical five-hole structure on the aircraft skin, combined with the failure criterion of multi crack structure and considering the random factors affecting the residual life distribution of multiple crack structure, this paper applies the branch and bound algorithm to the screening of the main failure modes of typical five-hole structure, and gives the specific screening steps. The residual life of the structure is predicted by Franc3D crack propagation software, and the life interference model is established. Finally, the residual life distribution curve of the five-hole structure is formed to complete the screening of its main failure modes. The results show that the efficiency of using the algorithm to screen the main failure modes of the structure has been improved by 77.2%, and the error between the corresponding median life and that before screening is about 12%, indicating that the result of screening the main failure modes of the structure by the algorithm is more accurate. Compared with the existing test results, the median life predicted by the life distribution is more conservative and has certain reliability and accuracy. This method has certain reference significance for the evaluation of the safe life of this multi-holes structure.","PeriodicalId":39691,"journal":{"name":"西北工业大学学报","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48799801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Image fusion method based on JBF and multi-order local region energy 基于JBF和多阶局部区域能量的图像融合方法

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061414

Feng Wang, Yongmei Cheng

引用次数: 0

A high or low temperature compensation bandgap reference voltage with pre-regulated voltage circuit 带预稳压电路的高或低温补偿带隙参考电压

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061360

Xiaoxuan Liu, Haisong Li, Tianjiao Cao, Tingsong Li

引用次数: 0

A feature extraction method for small sample data based on optimal ensemble random forest 一种基于最优集合随机森林的小样本数据特征提取方法

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061261

Wei Zhang, H. Zhang

{"title":"A feature extraction method for small sample data based on optimal ensemble random forest","authors":"Wei Zhang, H. Zhang","doi":"10.1051/jnwpu/20224061261","DOIUrl":"https://doi.org/10.1051/jnwpu/20224061261","url":null,"abstract":"High dimensional small sample data is the difficulty of data mining. When using the traditional random forest algorithm for feature selection, it is to have the poor stability and low accuracy of feature importance ranking caused by over fitting of classification results. Aiming at the difficulties of random forest in the dimensionality reduction of small sample data, a feature extraction algorithm ote-gwrffs is proposed based on small sample data. Firstly, the algorithm expands the samples based on the generated countermeasure network Gan to avoid the over fitting phenomenon of traditional random forest in the small sample classification. Then, on the basis of data expansion, the optimal tree set algorithm based on weight is adopted to reduce the impact of data distribution error on feature extraction accuracy and improve the overall stability of decision tree set. Finally, the weighted average of the weight and feature importance measure of a single decision tree is used to obtain the feature importance ranking, which solves the problem of low accuracy and poor stability in the feature selection process of small sample data. Through the UCI data set, the present algorithm is compared with the traditional random forest algorithm and the weight based random forest algorithm. The ote-gwrffs algorithm has higher stability and accuracy for processing high-dimensional and small sample data.","PeriodicalId":39691,"journal":{"name":"西北工业大学学报","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46958326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Enhanced beetle antennae search algorithm for spot color prediction 用于斑点颜色预测的增强型甲虫天线搜索算法

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061422

Zehai Gao, Yang Liu, Jie Chen, Molin Chu, Yan Zhang, Changsen Li

引用次数: 0

Study on passive location method of shallow water acoustic source with single hydrophone 浅水声源单水听器无源定位方法研究

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061278

Haijie Shi, Jinghua Li, Hong Chang

引用次数: 0

Multi-target assignment hunting strategy of UAV swarm based on improved K-means algorithm and shortest time mechanism 基于改进k -均值算法和最短时间机制的无人机群多目标分配狩猎策略

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061297

Bin Hu, Yahui Zhu, Zhize Du, Zixin Zhao, Yannian Zhou

{"title":"Multi-target assignment hunting strategy of UAV swarm based on improved K-means algorithm and shortest time mechanism","authors":"Bin Hu, Yahui Zhu, Zhize Du, Zixin Zhao, Yannian Zhou","doi":"10.1051/jnwpu/20224061297","DOIUrl":"https://doi.org/10.1051/jnwpu/20224061297","url":null,"abstract":"Multi-target hunting of UAV swarm is an important tactical means. This paper proposes a hunting strategy based on improved K-means and the shortest time mechanism. The large-scale task assignment problem is complex in structure and difficult to solve. To obtain higher hunting efficiency and reduce the amount of calculation on the single UAV, the hybrid architecture is used to decompose the complex multi-target hunting problem into a set of tasks that the UAV need to perform, which reduces the coupling of the system and the complexity of problem. Firstly, the multi-target hunting problem is stratified by the improved K-means algorithm to form multiple independent single target hunting subsystems. In the subsystem, the single target hunting task is decomposed into multiple subtasks that are easy to be executed by UAVs, and a one-to-one matching relationship between subtasks and UAVs is established by using the shortest time mechanism. UAV swarm can achieve multi-target hunting only by executing subtasks. The simulation results show that the UAV swarm can effectively allocate the multi-target hunting problem, which proves the effectiveness of the allocation strategy is proved.","PeriodicalId":39691,"journal":{"name":"西北工业大学学报","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48744833","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Analysis of earth pressure on geogrid reinforced retaining wall and improvement of its calculation method 土工格栅加筋挡土墙土压力分析及计算方法改进

西北工业大学学报 Pub Date : 2022-12-01 DOI: 10.1051/jnwpu/20224061366

Lihua Li, Zhigang Zheng, Han Yan, Shaoping Huang, Xinlong Zhou

引用次数: 0