本文根据轮胎的实际工作状态,提出一种轮胎动态力传递函数的测试方法,获得轮胎在运动状态下的径向一阶频率。在此基础上,结合对轮胎的均匀性与高阶谐波的研究结果,能够通过此频率预测出轮胎径向力波动较大的速度,可以为轮胎在整车配套...本文根据轮胎的实际工作状态,提出一种轮胎动态力传递函数的测试方法,获得轮胎在运动状态下的径向一阶频率。在此基础上,结合对轮胎的均匀性与高阶谐波的研究结果,能够通过此频率预测出轮胎径向力波动较大的速度,可以为轮胎在整车配套过程中遇到的NVH问题提供解决方案。According to the actual working state of the tire, this paper puts forward a test method of the dynamic force transmission function of the tire and obtains the radial first-order frequency of the tire in the moving state. On this basis, combined with the research results of tire uniformity and high-order harmonics, the speed of tire radial force variation can be predicted by this frequency, which can provide a solution for NVH problems encountered in the process of tire matching.展开更多
为研究浮式生产储卸油装置(floating production storage and offloading,FPSO)浮筒关键节点的疲劳强度问题,本文基于FPSO三舱段、浮筒锥体、浮筒转塔、锥形对接模块(mating cone module,MCM)的整体模型,通过应力分析确定出应力较为集...为研究浮式生产储卸油装置(floating production storage and offloading,FPSO)浮筒关键节点的疲劳强度问题,本文基于FPSO三舱段、浮筒锥体、浮筒转塔、锥形对接模块(mating cone module,MCM)的整体模型,通过应力分析确定出应力较为集中的区域并作为热点,建立精细化网格的子模型以获得热点应力。基于力传递函数的方法,根据规范开展浮筒和MCM的疲劳简化分析,研究系泊和立管载荷对浮筒局部结构的疲劳影响。结果表明,浮筒锥体、浮筒转塔和MCM中关键节点的疲劳强度均满足设计疲劳强度要求,其中最薄弱的热点结构HS1的疲劳寿命为3262 a,大于20 a的设计寿命,满足FPSO单点系泊浮筒的设计预期要求。展开更多
In this paper,the metal hydraulic engine mount (HEM) with the orifice is presented,the construction of HEM is consist of hydraulic cylinder and the spring on the bottom,its mechanical model is given and dynamics equat...In this paper,the metal hydraulic engine mount (HEM) with the orifice is presented,the construction of HEM is consist of hydraulic cylinder and the spring on the bottom,its mechanical model is given and dynamics equations are set up with considering kinematics conditions and continuous of fluid,the dynamics behavior of HEM including dynamic stiffness of fluid and transferability of HEM are studied here.The example of hydraulic engine mount is calculated,it is shown that the vibration reduction performance of the hydraulic engine mount of this paper is better.The analysis method of vibration reduction behavior for HEM in this paper can be used in designing of the reduction vibration devices and the HEM in this paper can be used in the practical engineering for reduction vibration.展开更多
A study is presented on the modulation of ripples induced by a long surface wave (LW) and a new theoretical modula-tion model is proposed. In this model, the wind surface stress modulation is related to the modulation...A study is presented on the modulation of ripples induced by a long surface wave (LW) and a new theoretical modula-tion model is proposed. In this model, the wind surface stress modulation is related to the modulation of ripple spectrum. The model results show that in the case of LW propagating in the wind direction with the wave age parameter of LW increasing, the area with enhanced shear stress shifts from the region near the LW crest on the upwind slope to the LW trough. With a smaller wave age parameter of LW, the ripple modulation has the maximum on the upwind slope in the vicinity of LW crest, while with a larger parameter the enhancement of ripple spectrum does not occur in that region. At low winds the amplitude of ripple modulation transfer function (MTF) is larger in the gravity wave range, while at moderate or high winds it changes little in the range from short gravity waves to capillary waves.展开更多
文摘本文根据轮胎的实际工作状态,提出一种轮胎动态力传递函数的测试方法,获得轮胎在运动状态下的径向一阶频率。在此基础上,结合对轮胎的均匀性与高阶谐波的研究结果,能够通过此频率预测出轮胎径向力波动较大的速度,可以为轮胎在整车配套过程中遇到的NVH问题提供解决方案。According to the actual working state of the tire, this paper puts forward a test method of the dynamic force transmission function of the tire and obtains the radial first-order frequency of the tire in the moving state. On this basis, combined with the research results of tire uniformity and high-order harmonics, the speed of tire radial force variation can be predicted by this frequency, which can provide a solution for NVH problems encountered in the process of tire matching.
文摘为研究浮式生产储卸油装置(floating production storage and offloading,FPSO)浮筒关键节点的疲劳强度问题,本文基于FPSO三舱段、浮筒锥体、浮筒转塔、锥形对接模块(mating cone module,MCM)的整体模型,通过应力分析确定出应力较为集中的区域并作为热点,建立精细化网格的子模型以获得热点应力。基于力传递函数的方法,根据规范开展浮筒和MCM的疲劳简化分析,研究系泊和立管载荷对浮筒局部结构的疲劳影响。结果表明,浮筒锥体、浮筒转塔和MCM中关键节点的疲劳强度均满足设计疲劳强度要求,其中最薄弱的热点结构HS1的疲劳寿命为3262 a,大于20 a的设计寿命,满足FPSO单点系泊浮筒的设计预期要求。
基金Supported by National Fund Committee for Study Abroad
文摘In this paper,the metal hydraulic engine mount (HEM) with the orifice is presented,the construction of HEM is consist of hydraulic cylinder and the spring on the bottom,its mechanical model is given and dynamics equations are set up with considering kinematics conditions and continuous of fluid,the dynamics behavior of HEM including dynamic stiffness of fluid and transferability of HEM are studied here.The example of hydraulic engine mount is calculated,it is shown that the vibration reduction performance of the hydraulic engine mount of this paper is better.The analysis method of vibration reduction behavior for HEM in this paper can be used in designing of the reduction vibration devices and the HEM in this paper can be used in the practical engineering for reduction vibration.
基金supported by the National Natural Science Foundation of China (Nos. 4047601 and U0933001)the Key Program of National Natural Science Foundation of China (No. 40830959)
文摘A study is presented on the modulation of ripples induced by a long surface wave (LW) and a new theoretical modula-tion model is proposed. In this model, the wind surface stress modulation is related to the modulation of ripple spectrum. The model results show that in the case of LW propagating in the wind direction with the wave age parameter of LW increasing, the area with enhanced shear stress shifts from the region near the LW crest on the upwind slope to the LW trough. With a smaller wave age parameter of LW, the ripple modulation has the maximum on the upwind slope in the vicinity of LW crest, while with a larger parameter the enhancement of ripple spectrum does not occur in that region. At low winds the amplitude of ripple modulation transfer function (MTF) is larger in the gravity wave range, while at moderate or high winds it changes little in the range from short gravity waves to capillary waves.
