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Numerical analysis of ossicular chain lesion of human ear

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Acta Mechanica Sinica 2009年第2期25卷 241-247页

作者： yingxi liu Sheng Li Xiuzhen Sun State Key Laboratory of Structural Analysis for IndustrialEquipment Dalian University of Technology116024 Dalian China ENT Department The Second Affiliated Hospital of DalianMedical University 116025 Dalian China

Abstract Lesion of ossicular chain is a common ear disease impairing the sense of hearing. A comprehensive numerical model of human ear can provide better understanding of sound transmission. In this study, we propose a three-dimensional finite element model of human ear that incorporates the canal, tympanic membrane, ossicular bones, middle ear suspensory ligaments/muscles, middle ear cavity and inner ear fluid. Numerical analysis is conducted and employed to predict the effects of middle ear cavity, malleus handle defect, hypoplasia of the long process of incus, and stapedial crus defect on sound transmission. The present finite element model is shown to be reasonable in predicting the ossicular mechanics of human ear.

关键词： Finite element model Ossicular chain lesionAcoustic-structural coupled analysis Middle ear cavity Sound transmission

Fatigue Analysis and Life Prediction of Dumpers with Cumulative Fatigue Damage Approach

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上海交通大学学报 2004年第z2期38卷 96-100页

作者： LI Shouju liu yingxi SUN Huiling State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian116024 China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian116024 China Department of Engineering Mechanics Dalian University of Technology Dalian116024China

A fatigue damage model is developed for evaluating accumulative fatigue damage of dumpers. The loading spectrums acted on dumpers are created according to measured strain data in field. The finite element analysis is carried out for assessing stress distribution and strength characteristics of dumpers. Fatigue damage indexes and service life are calculated by a modified Palmgren-Miner rule. The investigation shows that fatigue notch factor has a significant influence on the calculation of fatigue damage of dumpers.

关键词： fatigue life prediction dumper miner's rule finite element analysis loading spectrums

Numerical analysis of respiratory flow patterns within human upper airway

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Acta Mechanica Sinica 2009年第6期25卷 737-746页

作者： Ying Wang yingxi liu Xiuzhen Sun Shen Yu Fei Gao State Key Laboratory of Structural Analysisfor Industrial Equipment Dalian University of Technology116024 Dalian China Department of Otorhinalaryngology The Second Affiliated Hospital of Dalian Medical University116027 Dalian China

A computational fluid dynamics （CFD） approach is used to study the respiratory airflow dynamics within a human upper airway. The airway model which consists of the airway from nasal cavity, pharynx, larynx and trachea to triple bifurcation is built based on the CT images of a healthy volunteer and the Weibel model. The flow character- istics of the whole upper airway are quantitatively described at any time level of respiratory cycle. Simulation results of respiratory flow show good agreement with the clinical mea- sures, experimental and computational results in the litera- ture. The air mainly passes through the floor of the nasal cavity in the common, middle and inferior nasal meatus. The higher airway resistance and wall shear stresses are distrib- uted on the posterior nasal valve. Although the airways of pharynx, larynx and bronchi experience low shear stresses, it is notable that relatively high shear stresses are distrib- uted on the wall of epiglottis and bronchial bifurcations. Besides, two-dimensional fluid-structure interaction models of normal and abnormal airways are built to discuss the flow-induced deformation in various anatomy models. The result shows that the wall deformation in normal airway is relatively small.

关键词： Upper airway . Computational fluid dynamicsAirflow distribution .Resistance

Computational fluid dynamics simulations of respiratory airflow in human nasal cavity and its characteristic dimension study

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Acta Mechanica Sinica 2008年第2期24卷 223-228页

作者： Jun Zhang yingxi liu Xiuzhen Sun Shen Yu Chi Yu State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of Technology Dalian 116024 China Department of Otorhinolaryngology the Second Affiliated Hospital of Dalian Medical University Dalian 116027 China

To study the airflow distribution in human nasal cavity during respiration and the characteristic parameters of nasal structure, three-dimensional, anatomically accurate representations of 30 adult nasal cavity models were recons- tructed based on processed tomography images collected from normal people. The airflow fields in nasal cavities were simulated by fluid dynamics with finite element software ANSYS. The results showed that the difference of human nasal cavity structure led to different airflow distribution in the nasal cavities and variation of the main airstream passing through the common nasal meatus. The nasal resistance in the regions of nasal valve and nasal vestibule accounted for more than half of the overall resistance. The characteristic model of nasal cavity was extracted on the basis of characteristic points and dimensions deduced from the original models. It showed that either the geometric structure or the airflow field of the two kinds of models was similar. The characteristic dimensions were the characteristic parameters of nasal cavity that could properly represent the original model in model studies on nasal cavity.

关键词： Nasal cavity Characteristic dimension Three-dimensional reconstruction Numerical simulation of flowfield Computational fluid dynamic Finite element method

A TRIANGULAR QUASI-CONFORMING FINITE ELEMENT FOR TRANSIENT DYNAMIC ANALYSIS

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Acta Mechanica Sinica 1990年第1期6卷 59-63页

作者： liu yingxi Tang Limin, Dalian University of Technology 1. Dalian University of Technology Dalian China

A type of 3 node triangular element is constructed by the Quasi-conforming method, which may be used to solve the equation of a type of inverse problem of wave propagation after Laplace transformation △u-A^2u=0. The strains in the element are approximated by an expohential function and the string-net function between neigh- bouring elements is apporoximated by one dimensional general solution of the equation. Furthermore the strain field satisfies the equation, and therefore in the derivation of the element formulation, no shape function is needed. In this sense, it is a kind of hybrid element. Compared with the ordinary linear triangular element, the new one features higher precision with coarse meshes. Some numerical tests are presented.

关键词： quasi-conforming finite element method wave propagation equation

Static analysis of tympanic membrane in aero-otitis media by three-dimensional model of the middle ear

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Theoretical & Applied Mechanics Letters 2022年第2期12卷 111-117页

作者： Kaili Sun Xu Bie Zhixing Feng Shen Yu Xiuzhen Sun Jizhe Wang yingxi liu Lina Peng Zhaoxu Yao Department of Otolaryngology-Head and Neck Surgery The 2nd Affiliated Hospital of Dalian Medical UniversityDalian 116027China Department of Otolaryngology-Head and Neck Surgery Handan Central HospitalHandan 056001China Department of Engineering Mechanics Dalian University of TechnologyDalian 116024China

The three-dimensional(3D)model of the middle ear is of great significance to the research of middle ear related *** particular focus of this work is to simulate the impact of aircraft altitude and speed changes on the tympanic membrane(TM)during the descent phase,so as to analyze the pathogenesis of aero-otitis media and the mechanical response characteristics of TM under static *** simulations showed that the stress and strain of TM increase as the altitude difference and speed of the aircraft increase,and the maximum stress and strain areas are consistent with the clinical observation of TM ***,among many prevention and treatment measures of aero-otitis media,it is a therapeutic method to directly balance the pressure difference between the inner and outer TM.

关键词： Aero-otitis media The middle ear Numerical simulation Statics calculation Tympanostomy tube placement

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轮轨两点接触的有限元分析

机械工程学报 2005年第11期41卷 121-126页

作者：刘迎曦张军大连理工大学工业装备结构分析国家重点实验室大连116024 同济大学航空航天与力学学院上海200092

在轮轨单点接触计算分析的基础上,建立锥形踏面车轮的轮缘贴靠钢轨形成两点接触的计算模型,应用有限元参数二次规划法分析这一弹塑性接触问题。对不同载荷作用下的轮轨两点接触模型分别进行计算,得出了大量的轮轨接触状态、接触力的分... 详细信息

在轮轨单点接触计算分析的基础上,建立锥形踏面车轮的轮缘贴靠钢轨形成两点接触的计算模型,应用有限元参数二次规划法分析这一弹塑性接触问题。对不同载荷作用下的轮轨两点接触模型分别进行计算,得出了大量的轮轨接触状态、接触力的分布及变化规律。这些计算结果将有助于找到缓解钢轨侧磨和轮缘磨耗的方法。

关键词：两点接触有限元法参数二次规划法轮轨接触力

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战后日本集合住宅的发展

新建筑 2001年第2期 47-49页

作者：张菁刘颖曦天津大学建筑学院天津300072

概括介绍了日本在二次世界大战后５０年里，各个时期的集合住宅发展情况。２０世纪８０年代起日本年轻一代建筑师对集合住宅类型大胆的尝试，使日本集合住宅出现了多元化的趋势。

关键词：日本集合住宅多元化住宅功能

Numerical simulation of soft palate movement and airflow in human upper airway by fluid-structure interaction method

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Acta Mechanica Sinica 2007年第4期23卷 359-367页

作者： Xiuzhen Sun Chi Yu Yuefang Wang yingxi liu State Key Lab.of Struct.Anal.for Ind.Equip.,Dalian University of Technology,Dalian 116024,China The Second Affiliated Hospital,Dalian Medical University,Dalian 116027,China State Key Lab. of Struct. Anal. for Ind. Equip. Dalian University of Technology Dalian 116024 China The Second Affiliated Hospital Dalian Medical University Dalian 116027 China

In this paper, the authors present airflow field characteristics of human upper airway and soft palate movement attitude during breathing. On the basis of the data taken from the spiral computerized tomography images of a healthy person and a patient with Obstructive Sleep Apnea-Hypopnea Syndrome （OSAHS）, three-dimensional models of upper airway cavity and soft palate are reconstructed by the method of surface rendering. Numerical simulation is performed for airflow in the upper airway and displacement of soft palate by fluid-structure interaction analysis. The reconstructed threedimensional models precisely preserve the original configuration of upper airways and soft palate. The results of the pressure and velocity distributions in the airflow field are quantitatively determined, and the displacement of soft palate is presented. Pressure gradients of airway are lower for the healthy person and the airflow distribution is quite uniform in the case of free breathing. However, the OSAHS patient remarkably escalates both the pressure and velocity in the upper airway, and causes higher displacement of the soft palate. The present study is useful in revealing pathogenesis and quantitative mutual relationship between configuration and function of the upper airway as well as in diagnosingdiseases related to anatomical structure and function of the upper airway.

关键词： Obstructive sleep apnea-hypopnea syndrome Upper airway Soft palate Three-dimensional finiteelement reconstruction Fluid-structure interaction Numerical simulation