RECOGNITION OF STRUCTURAL DIAGRAM OF MACHINE TOOL SPEED CHANGE SYSTEM WITH ANY COMPOSITE RATIO

ＲＥＣＯＧＮＩＴＩＯＮＯＦＳＴＲＵＣＴＵＲＡＬＤＩＡＧＲＡＭＯＦＭＡＣＨＩＮＥＴＯＯＬＳＰＥＥＤＣＨＡＮＧＥＳＹＳＴＥＭＷＩＴＨＡＮＹＣＯＭＰＯＳＩＴＥＲＡＴＩＯＲＥＣＯＧＮＩＴＩＯＮＯＦＳＴＲＵＣＴＵＲＡＬＤＩＡＧＲＡＭＯＦＭＡＣＨＩＮＥＴＯＯＬＳ...     

CALCULATION AND EXPERIMENTAL INVESTIGATION OF ELECTRIC FIELDS INDUCED BY ELECTRODES IN ELECTROSTATIC CHARGED POWDER SPRAYING TECHNIQUE

ＣＡＬＣＵＬＡＴＩＯＮＡＮＤＥＸＰＥＲＩＭＥＮＴＡＬＩＮＶＥＳＴＩＧＡＴＩＯＮＯＦＥＬＥＣＴＲＩＣＦＩＥＬＤＳＩＮＤＵＣＥＤＢＹＥＬＥＣＴＲＯＤＥＳＩＮＥＬＥＣＴＲＯＳＴＡＴＩＣＣＨＡＲＧＥＤＰＯＷＤＥＲＳＰＲＡＹＩＮＧＴＥＣＨＮＩＱＵＥＣＡＬＣＵＬ...     

THREE DIMENSIONAL ELASTO-PLASTIC CONTACT BOUNDARY ELEMENT ANALYSIS FOR ROLLING WITH CONSIDERATION OF FRICTION

ＴＨＲＥＥＤＩＭＥＮＳＩＯＮＡＬＥＬＡＳＴＯＰＬＡＳＴＩＣＣＯＮＴＡＣＴＢＯＵＮＤＡＲＹＥＬＥＭＥＮＴＡＮＡＬＹＳＩＳＦＯＲＲＯＬＬＩＮＧＷＩＴＨＣＯＮＳＩＤＥＲＡＴＩＯＮＯＦＦＲＩＣＴＩＯＮ①ＸｉａｏＨｏｎｇＣｈｅｎＹｉｍｉｎｇＳｈｅｎＧｕａｎｇ...     

FINITE ELEMENT SOLUTION TO COUPLED THERMO－ELASTICCONTACT STRESS AND IMPACTRESPONSE OF MESHING GEARS

ＦＩＮＩＴＥＥＬＥＭＥＮＴＳＯＬＵＴＩＯＮＴＯＣＯＵＰＬＥＤＴＨＥＲＭＯ－ＥＬＡＳＴＩＣＣＯＮＴＡＣＴＳＴＲＥＳＳＡＮＤＩＭＰＡＣＴＲＥＳＰＯＮＳＥＯＦＭＥＳＨＩＮＧＧＥＡＲＳＬｉＲｕｎｆａｎｇ；ＯｕＨｅｎｇａｎ（ＣｈｏｎｇｑｉｎｇＵｎｉｖｅｒｓｉｔ...     

STUDY ON AUTOMATIC POLISHING AT CONSTANT PRESSURE INTENSITY

ＳＴＵＤＹＯＮＡＵＴＯＭＡＴＩＣＰＯＬＩＳＨＩＮＧＯＦＭＯＵＬＤＣＵＲＶＥＤＳＵＲＦＡＣＥＡＴＣＯＮＳＴＡＮＴＰＲＥＳＳＵＲＥＩＮＴＥＮＳＩＴＹＳＴＵＤＹＯＮＡＵＴＯＭＡＴＩＣＰＯＬＩＳＨＩＮＧＯＦＭＯＵＬＤＣＵＲＶＥＤＳＵＲＦＡＣＥＡＴＣＯＮＳＴＡ...     

ANALYSIS OF ROLLING BY ELASTO-PLASTIC FINITE DEFORMATION CONTACT BOUNDARY ELEMENT METHOD

ＡＮＡＬＹＳＩＳＯＦＲＯＬＬＩＮＧＢＹＥＬＡＳＴＯＰＬＡＳＴＩＣＦＩＮＩＴＥＤＥＦＯＲＭＡＴＩＯＮＣＯＮＴＡＣＴＢＯＵＮＤＡＲＹＥＬＥＭＥＮＴＭＥＴＨＯＤＨｕａｎｇＱｉｎｇｘｕｅＳｈｅｎＧｕａｎｇｘｉａｎＸｉａｏＨｏｎｇＴａｉｙｕａｎＨｅａｖｙＭａ...     

STUDY ON TESTING TECHNIQUE FOR MEASUREMENT OF FATIGUE－CREEP INTERACTION RESISTANCE

ＳＴＵＤＹＯＮＴＥＳＴＩＮＧＴＥＣＨＮＩＱＵＥＦＯＲＭＥＡＳＵＲＥＭＥＮＴＯＦＦＡＴＩＧＵＥ－ＣＲＥＥＰＩＮＴＥＲＡＣＴＩＯＮＲＥＳＩＳＴＡＮＣＥＳＴＵＤＹＯＮＴＥＳＴＩＮＧＴＥＣＨＮＩＱＵＥＦＯＲＭＥＡＳＵＲＥＭＥＮＴＯＦＦＡＴＩＧＵＥ－ＣＲＥＥＰ...     

PREDICTION OF PUMP CHARACTERISTICS ACCORDING TO GEOMETRICAL PARAMETERS OF IMPELLER AND VOLUTE CASING

ＰＲＥＤＩＣＴＩＯＮＯＦＰＵＭＰＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＡＣＣＯＲＤＩＮＧＴＯＧＥＯＭＥＴＲＩＣＡＬＰＡＲＡＭＥＴＥＲＳＯＦＩＭＰＥＬＬＥＲＡＮＤＶＯＬＵＴＥＣＡＳＩＮＧＰＲＥＤＩＣＴＩＯＮＯＦＰＵＭＰＣＨＡＲＡＣＴＥＲＩＳＴＩＣＳＡＣＣＯＲＤ...     

SOLVING CONTACT PROBLEM WITH FRICTION BY A NEW FAST BOUNDARY ELEMENT METHOD

ＳＯＬＶＩＮＧＣＯＮＴＡＣＴＰＲＯＢＬＥＭＷＩＴＨＦＲＩＣＴＩＯＮＢＹＡＮＥＷＦＡＳＴＢＯＵＮＤＡＲＹＥＬＥＭＥＮＴＭＥＴＨＯＤＨｕａｎｇＱｉｎｇｘｕｅＴａｉｙｕａｎＨｅａｖｙＭａｃｈｉｎｅｒｙＩｎｓｔｉｔｕｔｅＤｕＱｕｎｇｕｉＳｏｕｔｈＣｈｉｎａＵ...     

REGULARITY OF VIBRATION RESPONSE OF MECHANICAL SYSTEM UNDER AFFECT OF VARI-FREQUENCY EXCITING FORCE

ＲＥＧＵＬＡＲＩＴＹＯＦＶＩＢＲＡＴＩＯＮＲＥＳＰＯＮＳＥＯＦＭＥＣＨＡＮＩＣＡＬＳＹＳＴＥＭＵＮＤＥＲＡＦＦＥＣＴＯＦＶＡＲＩ－ＦＲＥＱＵＥＮＣＹＥＸＣＩＴＩＮＧＦＯＲＣＥＲＥＧＵＬＡＲＩＴＹＯＦＶＩＢＲＡＴＩＯＮＲＥＳＰＯＮＳＥＯＦＭＥＣＨＡＮＩ...     

基于刚柔耦合多体系统的发动机曲轴疲劳分析

在LMS(Leuven Measurement&System)中建立某型V8发动机曲轴系统的多体动力学模型,通过刚柔耦合动力学计算,得到部件的模态参与因子,将模态参与因子与模态进行线性叠加,得到部件的载荷历程,并将其作为疲劳分析的输入数据;利用LMS.Virtual.Lab的Durability模块对曲轴进行有限元疲劳分析,获得精确的曲轴疲劳寿命值和损伤分布.结论是:通过系统多柔体动力学仿真可以得到各阶模态参与因子的时间历程曲线和部件的载荷历程,同时保证了模态参与因子与有限元模型匹配;曲轴集中应力最大且寿命最短处为轴颈与曲柄的过渡圆角处.     

压缩机曲轴断裂失效分析

针对天然气压缩机的球墨铸铁曲轴的断裂事故进行了失效分析,通过对曲轴的断口形貌和铸造材质缺陷分析,判断出曲轴断裂属于过载脆性断裂,曲轴材质的铸造大气孔、疏松和粗大石墨相是造成曲轴断裂的主要原因,并提出了预防措施。     

Markov Chain Modelling of Reliability Analysis and Prediction under Mixed Mode Loading

The reliability assessment for an automobile crankshaft provides an important understanding in dealing with the design life of the component in order to eliminate or reduce the likelihood of failure and safety risks.The failures of the crankshafts are considered as a catastrophic failure that leads towards a severe failure of the engine block and its other connecting subcomponents.The reliability of an automotive crankshaft under mixed mode loading using the Markov Chain Model is studied.The Markov Chain is modelled by using a two-state condition to represent the bending and torsion loads that would occur on the crankshaft.The automotive crankshaft represents a good case study of a component under mixed mode loading due to the rotating bending and torsion stresses.An estimation of the Weibull shape parameter is used to obtain the probability density function,cumulative distribution function,hazard and reliability rate functions,the bathtub curve and the mean time to failure.The various properties of the shape parameter is used to model the failure characteristic through the bathtub curve is shown.Likewise,an understanding of the patterns posed by the hazard rate onto the component can be used to improve the design and increase the life cycle based on the reliability and dependability of the component.The proposed reliability assessment provides an accurate,efficient,fast and cost effective reliability analysis in contrast to costly and lengthy experimental techniques.     

往复压缩机曲轴强度分析

基于热动力计算的结果,通过利用Ansys建立轴系的三维模型,对整体曲轴进行了应力计算,得到了危险节点处的应力变化曲线以及在载荷变化周期内的最大应力幅值,最后校核了静强度和疲劳强度.结果表明设计工况下该轴系的强度符合设计规范要求,同时为同类型压缩机曲轴设计提供了理论依据.     

曲轴的疲劳断裂分析

系统阐述利用有限元法对机械结构零部件进行疲劳断裂分析的相关理论和方法。在此基础上对16V240机车柴油机曲轴的最危险曲拐进行最大和最小工况下的三维有限元分析，确定裂纹易产生的危险截面，求解危险截面处不同深度和形态的表面椭圆裂纹的应力强度因子，并拟合关于椭圆裂纹特征参数及总体坐标下的等效应力强度因子的近似表达式。为预测含裂纹曲轴的承载能力、剩余寿命、制定判废标准等提供相关的疲劳断裂参数。     

Discretized Markov chain in damage assessment using Rainflow cycle with effects of mean stress on an automobile crankshaft

We studied the effect of mean stress correction factor using the Rainflow counting technique to assess the fatigue damage of an automobile crankshaft under service loading by considering the stochastic process of the Markov chain. The failure of the crankshaft will cause serious damage to the engine and also to other connecting subcomponents. The service loading is computationally generated from the Discrete Markov chain model and the fatigue cycle is counted using the Rainflow counting technique with the consideration of the local minima and maxima load. To quantify the fatigue damage, the strain-life curve using the fatigue mean stresses was used to model the fatigue failure of the material used in for the crankshaft at N _f = 10 ⁶ . The fatigue mean stresses were used to estimate the effects of the mean stress on the fatigue strength of the component under service loading condition. Statistical verification with the boundary condition of the 90% confidence level was performed to observe the difference between the stochastic algorithms when compared towards the fatigue life behavior of the ductile cast iron material. We concluded that for the practical application, the proposed stochastic model provides a highly accurate assessment of fatigue damage prediction for improving the safety and controlling the risk factors in terms of structural health monitoring.     

转子式空调压缩机曲轴法兰系统摩擦噪声预测

转子式空调压缩机摩擦噪声主要来源于其内部相互接触的各个运动副.为识别转子式空调压缩机摩擦噪声的来源,通过销盘实验测定曲轴与上下法兰组成的系统中不同摩擦副的摩擦因数,拟合得到摩擦-速度负斜率曲线;建立曲轴法兰系统的有限元模型,以摩擦-速度负斜率曲线加载,提取其复特征值和等效阻尼比,初步分析摩擦噪声可能发生的频率.对实际采...     

不同强度理论在曲轴疲劳研究中的对比应用

采用有限元法对曲轴在弯矩载荷作用下的应力状态进行分析,并结合插值法对曲轴的应力分布进行拟合计算,在此基础上采用临界距离法与不同强度理论对相同材料、不同圆角半径的曲轴的结构疲劳特性进行预测研究,并对预测结果进行试验验证。研究结果表明：当基于第一强度理论与临界距离法对圆角半径不同的曲轴的疲劳特性进行预测时,无论是临界点法还是临界线法都会造成较大误差;而当基于第三及第四强度理论与临界距离法进行预测时,临界线法比临界点法的预测精度更高,分析认为这是由曲轴的破坏类型造成的。     

大型活塞压缩机曲轴振动分析（一）——模态分析

随着往复压缩机向大型化和高速化方向发展,曲轴因扭振而产生破坏的可能性在迅速增大,对压缩机曲轴扭振研究的要求越来越迫切。而影响曲轴扭振的最主要因素是曲轴的模态。以某大型压缩机曲轴为例,对曲轴进行简化,利用ANSYS软件以Timoshenko 3-节点梁单元为基础,考虑轴承油膜的作用,对压缩机曲轴模态进行了计算。该模型还可以用来对曲轴进行谐响应分析和强迫振动分析。利用Lanzos方法提取了曲轴前7阶模态,结果显示曲轴的第一阶模态为29.073Hz,振型为整体扭转振动。考虑吸排气过程中气阀阀片运动产生的气流脉动对激振力的影响,对激振力进行傅里叶分解,得出激振力的功率谱密度图,以判断该曲轴在工作条件下是否会发生扭转共振。     

基于Workbench的内燃机曲轴模态分析

曲轴是内燃机中主要的运动部件之一,在周期变化的载荷作用下,曲轴系统可能在发动机转速范围内发生共振,使曲轴出现弯曲疲劳破坏和扭转疲劳破坏,因此有必要对曲轴进行动态特性分析.文中通过Pro/E建立曲轴的几何模型,在ANSYS Workbench中完成曲轴的固有特性分析,得到曲轴前六阶固有频率及振型,为曲轴的动力学分析提供依据.