齿轮是最常用的传动部件,其常见的失效模式为齿面点蚀与齿根断裂。为了快速、精确地对其进行可靠性分析,提出了一种考虑失效相关的改进四阶矩法。首先,根据失效机制分别建立齿面接触疲劳与齿根弯曲断裂失效的可靠性模型。其次,为提高传...齿轮是最常用的传动部件,其常见的失效模式为齿面点蚀与齿根断裂。为了快速、精确地对其进行可靠性分析,提出了一种考虑失效相关的改进四阶矩法。首先,根据失效机制分别建立齿面接触疲劳与齿根弯曲断裂失效的可靠性模型。其次,为提高传统四阶矩求解精度,先使用改进一次二阶矩法求出的二阶可靠性指标,再求得新四阶可靠性指标,从而提高单一失效模式的可靠性求解精度;然后,基于条件概率降维法计算多失效模式间的相关度及考虑失效相关时的整体失效概率。最后,以某系统的传动齿轮为例,比较了所提方法、均值一次二阶矩(Mean Value First Order Second Moment,MVFOSM)法、改进一次二阶矩(Advanced First Order Second Moment,AFOSM)法和传统高阶矩标准化技术(High-Order Moment Standardization Technique,HOMST)法的计算效果。结果显示,所提方法在精度和效率上都得到了较大的提升,提供了一种分析多失效模式可靠性的理论方法。展开更多
In the reliability designing procedure of the vehicle components, when the distribution styles of the random variables are unknown or non-normal distribution, the result evaluated contains great error or even is wrong...In the reliability designing procedure of the vehicle components, when the distribution styles of the random variables are unknown or non-normal distribution, the result evaluated contains great error or even is wrong if the reliability value R is larger than 1 by using the existent method, in which case the formula is necessary to be revised. This is obviously inconvenient for programming. Combining reliability-based optimization theory, robust designing method and reliability based sensitivity analysis, a new method for reliability robust designing is proposed. Therefore the influence level of the designing parameters’ changing to the reliability of vehicle components can be obtained. The reliability sensitivity with respect to design parameters is viewed as a sub-objective function in the multi-objective optimization problem satisfying reliability constraints. Given the first four moments of basic random variables, a fourth-moment technique and the proposed optimization procedure can obtain reliability-based robust design of automobile components with non-normal distribution parameters accurately and quickly. By using the proposed method, the distribution style of the random parameters is relaxed. Therefore it is much closer to the actual reliability problems. The numerical examples indicate the following: (1) The reliability value obtained by the robust method proposed increases (】0.04%) comparing to the value obtained by the ordinary optimization algorithm; (2) The absolute value of reliability-based sensitivity decreases (】0.01%), and the robustness of the products’ quality is improved accordingly. Utilizing the reliability-based optimization and robust design method in the reliability designing procedure reduces the manufacture cost and provides the theoretical basis for the reliability and robust design of the vehicle components.展开更多
文摘齿轮是最常用的传动部件,其常见的失效模式为齿面点蚀与齿根断裂。为了快速、精确地对其进行可靠性分析,提出了一种考虑失效相关的改进四阶矩法。首先,根据失效机制分别建立齿面接触疲劳与齿根弯曲断裂失效的可靠性模型。其次,为提高传统四阶矩求解精度,先使用改进一次二阶矩法求出的二阶可靠性指标,再求得新四阶可靠性指标,从而提高单一失效模式的可靠性求解精度;然后,基于条件概率降维法计算多失效模式间的相关度及考虑失效相关时的整体失效概率。最后,以某系统的传动齿轮为例,比较了所提方法、均值一次二阶矩(Mean Value First Order Second Moment,MVFOSM)法、改进一次二阶矩(Advanced First Order Second Moment,AFOSM)法和传统高阶矩标准化技术(High-Order Moment Standardization Technique,HOMST)法的计算效果。结果显示,所提方法在精度和效率上都得到了较大的提升,提供了一种分析多失效模式可靠性的理论方法。
基金supported by National Natural Science Foundation of China (Grant Nos. 51135003, U1234208, 51205050)New Teachers' Fund for Doctor Stations of Ministry of Education of China (Grant No.20110042120020)+1 种基金Fundamental Research Funds for the Central Universities, China (Grant No. N110303003)China Postdoctoral Science Foundation (Grant No. 2011M500564)
文摘In the reliability designing procedure of the vehicle components, when the distribution styles of the random variables are unknown or non-normal distribution, the result evaluated contains great error or even is wrong if the reliability value R is larger than 1 by using the existent method, in which case the formula is necessary to be revised. This is obviously inconvenient for programming. Combining reliability-based optimization theory, robust designing method and reliability based sensitivity analysis, a new method for reliability robust designing is proposed. Therefore the influence level of the designing parameters’ changing to the reliability of vehicle components can be obtained. The reliability sensitivity with respect to design parameters is viewed as a sub-objective function in the multi-objective optimization problem satisfying reliability constraints. Given the first four moments of basic random variables, a fourth-moment technique and the proposed optimization procedure can obtain reliability-based robust design of automobile components with non-normal distribution parameters accurately and quickly. By using the proposed method, the distribution style of the random parameters is relaxed. Therefore it is much closer to the actual reliability problems. The numerical examples indicate the following: (1) The reliability value obtained by the robust method proposed increases (】0.04%) comparing to the value obtained by the ordinary optimization algorithm; (2) The absolute value of reliability-based sensitivity decreases (】0.01%), and the robustness of the products’ quality is improved accordingly. Utilizing the reliability-based optimization and robust design method in the reliability designing procedure reduces the manufacture cost and provides the theoretical basis for the reliability and robust design of the vehicle components.
