振动与冲击 Pub Date : 2017-10-15 DOI: 10.13465/J.CNKI.JVS.2017.19.028

Zhaohui Lu, Yiyu Lu, M. Hood, Pan Linhua, Pei He

{"title":"Numerical simulation and analysis on the flow field structure and hard rock erosion potential of a disc-slotted pulse water jet","authors":"Zhaohui Lu, Yiyu Lu, M. Hood, Pan Linhua, Pei He","doi":"10.13465/J.CNKI.JVS.2017.19.028","DOIUrl":"https://doi.org/10.13465/J.CNKI.JVS.2017.19.028","url":null,"abstract":"A disc-slotted pulse water jet is a potential tool to break hard rock due to its special loading styles, such as the water hammer pressure, ultra-speed lateral jetting and pulse dynamic load etc. Aiming at investigating the flow filed of the jet, a two-phase-flow transient computational model, matching with the geometry and motion of the interrupted water jet generating device, was established to simulate the dynamic evolution and characteristics of a single pulsation within 100 mm standoff based on the volume of fluid (VOF) model and dynamic mesh theory. The results show that at the head of the pulsed jet forms a deflective slug structure which is consistent with the result from high-speed photography experiments. The slug head velocity is lower than that at the jet outlet and the jet turbulence is mainly distributed over boundary layers between jet and air and at the deflective side. Tile-shaped stereo-structure is yielded during the pulse formation process. It presents non-axisymmetric flow pattern when impacting target, which consists with the irregular erosion cavity obtained by hard rock fragmentation experiments.","PeriodicalId":39722,"journal":{"name":"振动与冲击","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87721687","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: 5

Modal parametric identification of distribution type structures based on random decrement technique 基于随机减量技术的分布型结构模态参数辨识

振动与冲击 Pub Date : 2017-09-15 DOI: 10.13465/J.CNKI.JVS.2017.17.008.HTML

Jingzhou Lu, S. Sim, B. Spencer

引用次数: 0

Finite element analysis of the effect of material properties on human thoracic impact response 材料性能对人体胸部冲击反应影响的有限元分析

振动与冲击 Pub Date : 2016-01-01 DOI: 10.13465/j.cnki.jvs.2016.08.015

Fang Wang, Yong Han, Guibing Li, Jikuang Yang

{"title":"Finite element analysis of the effect of material properties on human thoracic impact response","authors":"Fang Wang, Yong Han, Guibing Li, Jikuang Yang","doi":"10.13465/j.cnki.jvs.2016.08.015","DOIUrl":"https://doi.org/10.13465/j.cnki.jvs.2016.08.015","url":null,"abstract":"The purpose of the current study was to analyze the influence of changes of the material of the human thoracic skeleton and soft tissues on the thorax responses under frontal impact loading conditions. A series of human thorax impact simulations were conducted based on a developed and validated human thorax finite element (FE) model. A number of thoracic response parameters were output to investigate the effect of material property changes on the predicted thoracic responses by using polynomial fitting analysis. The results of the simulations indicated that varying thoracic material properties affects the impact responses with different level. The impact force (Fmax) and chest deflection (Dmax) were obviously affected, and the number of rib fractures (NRF) and T12 accelerations (Gmax-T12) were additionally affected by the material properties. However, the influences of the material properties on the deflection rate (Vmax) and T1 acceleration (Gmax-T1) were small. Specifically, the Fmax, Dmax, and Gmax-T12 were mainly influenced by the soft tissue material properties, while the NRF was primarily determined by the thoracic skeletal structure material properties.","PeriodicalId":39722,"journal":{"name":"振动与冲击","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82808002","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

The study of acoustic emission monitoring for contact state of seal end faces 密封端面接触状态的声发射监测研究

振动与冲击 Pub Date : 2016-01-01 DOI: 10.13465/J.CNKI.JVS.2016.08.014

Xiaohui Li, P. Fu, Lt, strong gt, Weiqing Cao, Kan Chen

引用次数: 2

Pedestrian lower extremity injury risk in car-pedestrian collisions 汽车-行人碰撞中行人下肢损伤的风险

振动与冲击 Pub Date : 2016-01-01 DOI: 10.13465/J.CNKI.JVS.2016.23.001

B. Wang, Jikuang Yang, D. Otte, F. Wang

引用次数: 8

Fault diagnosis method based on sensitive feature selection and manifold learning dimension reduction 基于敏感特征选择和流形学习降维的故障诊断方法

振动与冲击 Pub Date : 2014-01-01 DOI: 10.13465/J.CNKI.JVS.2014.03.014

Lt, strong gt, Zuqiang Su, B. Tang, Jinbao Yao