Dynamic reliability models of mechanical load-sharing parallel systems considering strength degradation of components

2014 ◽  
Vol 229 (13) ◽  
pp. 2484-2495 ◽  
Author(s):  
Peng Gao ◽  
Liyang Xie
Keyword(s):  
Failure Rate ◽  
Mechanical Load ◽  
Parallel Systems ◽  
Load Sharing ◽  
Strength Degradation ◽  
Random Load ◽  
Dynamic Reliability ◽  
Reliability Models ◽  
Load Redistribution ◽  
Mechanical Components

Conventional reliability analysis of load-sharing parallel systems is mainly based on failure rate of components, in which failure dependence of components and load redistribution are also characterized by specified failure rates. However, the failure rate of mechanical components always varies with time, which is difficult to measure. Therefore, in this paper, quantitative dynamic reliability models of mechanical load-sharing parallel systems are developed in terms of stress parameters and strength parameters rather than failure rate of components, which consider the degradation mechanism of mechanical components. The proposed models take into account the strength degradation path dependence (SDPD) of a component, the strength degradation process dependence between different components in a system, and the random load redistribution. In addition, Monte Carlo simulation is carried out to verify the proposed models. The results show that SDPD and the load-sharing effect have considerable influences on dynamic reliability of mechanical load-sharing parallel systems.

scholarly journals Reliability Evaluation Based on Different Distributions of Random Load

2013 ◽  
Vol 2013 ◽  
pp. 1-7
Author(s):  
Peng Gao ◽  
Liyang Xie
Keyword(s):  
Dynamic Change ◽  
Strength Degradation ◽  
Longitudinal Distribution ◽  
Reliability Model ◽  
Random Load ◽  
Dynamic Reliability ◽  
Initial Strength ◽  
Reliability Models ◽  
Model Based ◽  
Definition Of

The reliability models of the components under the nonstationary random load are developed in this paper. Through the definition of the distribution of the random load, it can be seen that the conventional load-strength interference model is suitable for the calculation of the static reliability of the components, which does not reflect the dynamic change in the reliability and cannot be used to evaluate the dynamic reliability. Therefore, by developing an approach to converting the nonstationary random load into the random load whose pdf is the same at each moment when the random load applies, the reliability model based on the longitudinal distribution is derived. Moreover, through the definition of the transverse standard load and the transverse standard load coefficient, the reliability model based on the transverse distribution is derived. When the occurrence of the random load follows the Poisson process, the dynamic reliability models considering the strength degradation are derived. These models take the correlation between the random load and the strength into consideration. The result shows that the dispersion of the initial strength and that of the transverse standard load coefficient have great influences on the reliability and the hazard rate of the components.

scholarly journals Reliability and Random Lifetime Models of Planetary Gear Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Peng Gao ◽  
Liyang Xie ◽  
Wei Hu
Keyword(s):  
Load Distribution ◽  
Planetary Gear ◽  
Working Process ◽  
Random Load ◽  
Working Mechanism ◽  
Dynamic Reliability ◽  
Reliability Models ◽  
Process Failure ◽  
Failure Dependence ◽  
Gear Systems

Conventional reliability models of planetary gear systems are mainly static. In this paper, dynamic reliability models and random lifetime models of planetary gear systems are developed with dynamic working mechanism considered. The load parameters, the geometric parameters, and the material parameters are taken as the inputs of the reliability models and the random lifetime models. Moreover, failure dependence and dynamic random load redistributions are taken into account in the models. Monte Carlo simulations are carried out to validate the proposed models. The results show that the randomness of the load distribution is obvious in the system working process. Failure dependence has significant influences on system reliability. Moreover, the dispersion of external load has great impacts on the reliability, lifetime distribution, and redundancy of planetary gear systems.

scholarly journals Dynamic Reliability Analysis Method of Degraded Mechanical Components Based on Process Probability Density Function of Stress

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Peng Gao ◽  
Liyang Xie
Keyword(s):  
Probability Density Function ◽  
Probability Density ◽  
Density Function ◽  
Solar Array ◽  
Dynamic Reliability ◽  
Reliability Models ◽  
Practical Engineering ◽  
Mechanical Components ◽  
Reliability Computation ◽  
Probability Density Function Pdf

It is necessary to develop dynamic reliability models when considering strength degradation of mechanical components. Instant probability density function (IPDF) of stress and process probability density function (PPDF) of stress, which are obtained via different statistical methods, are defined, respectively. In practical engineering, the probability density function (PDF) for the usage of mechanical components is mostly PPDF, such as the PDF acquired via the rain flow counting method. For the convenience of application, IPDF is always approximated by PPDF when using the existing dynamic reliability models. However, it may cause errors in the reliability calculation due to the approximation of IPDF by PPDF. Therefore, dynamic reliability models directly based on PPDF of stress are developed in this paper. Furthermore, the proposed models can be used for reliability assessment in the case of small amount of stress process samples by employing the fuzzy set theory. In addition, the mechanical components in solar array of satellites are chosen as representative examples to illustrate the proposed models. The results show that errors are caused because of the approximation of IPDF by PPDF and the proposed models are accurate in the reliability computation.

Reliability analysis of load-sharing parallel systems considering equivalent strength degradation

2020 ◽  
pp. 1748006X2096842
Author(s):  
Xinshui Yu ◽  
Tianxiang Yu ◽  
Kunling Song ◽  
Bifeng Song
Keyword(s):  
Parallel Systems ◽  
Original System ◽  
Load Sharing ◽  
Degradation Process ◽  
Strength Degradation ◽  
Parallel System ◽  
Failure Behavior ◽  
Initial Strength ◽  
Reliability Method ◽  
Equivalent Strength

In this paper, a new reliability method for load-sharing parallel systems with dependent components that share the workload equally before and after some components have failed is studied. In the working process of a load-sharing parallel system, after the failure of some components, the surviving components share the original system workload with higher components loads. The states of all the components are dependent. The failure behavior of a component impacts the strength degradation process of the remaining working components. For a load-sharing parallel system, one component works the whole system works, which means the component with the largest initial strength works, the whole system works. Firstly, we use the equivalent strength degradation theory to get the remaining strength of the component with the largest initial strength after some components fail. Then, the stress-strength interference model will be used to calculate the reliability after some components fail. Finally, the proposed method is illustrated by a numerical example and verified by the Monte Carlo simulation method.

Optimization Design on Dynamic Reliability of a Tension Bar

2011 ◽  
Vol 415-417 ◽  
pp. 807-812
Author(s):  
Xin Gang Wang ◽  
Bao Yan Wang ◽  
Xiu Feng Tan
Keyword(s):  
Optimization Design ◽  
Theoretical Data ◽  
Computational Method ◽  
Design Parameters ◽  
Arbitrary Distribution ◽  
Random Load ◽  
Reliability Design ◽  
Dynamic Reliability ◽  
Reliability Sensitivity ◽  
Mechanical Components

This template explains and demonstrates how to prepare your camera-ready paper for Trans Tech Publications. The best is to read these instructions and follow the outline of this text. The variation rules of strength, load, and reliability of mechanical components are studied with a change in time, and a model is established for dynamic reliability of mechanical components under the random load acting. By combining the theory of reliability design with the method of sensitivity analysis, the computational method of dynamic reliability sensitivity design with arbitrary distribution parameter is proposed based on the methods Edgeworth and perturbation, and the problem of dynamic reliability sensitivity design of mechanical components distributed arbitrary distribution is solved as well as the variation rules of dynamic reliability sensitivity are given. The variation of reliability is studied as design parameters change a little, which provides theoretical data for dynamic reliability design of mechanical components.

Dynamic Reliability Sensitivity Analysis of Torsion Bar

2008 ◽  
Vol 44-46 ◽  
pp. 275-282 ◽  
Author(s):  
Xin Gang Wang ◽  
Yi Min Zhang ◽  
Y.F. Yan ◽  
Bao Yan Wang
Keyword(s):  
Sensitivity Analysis ◽  
Design Theory ◽  
Equation Model ◽  
Design Parameters ◽  
Random Load ◽  
Reliability Design ◽  
Dynamic Reliability ◽  
Reliability Sensitivity ◽  
Mechanical Components ◽  
Torsion Bar

In this paper, the variation rules of strength, load, reliability and failure rate of mechanical components are studied with time, and a state equation model for dynamic reliability of mechanical components is established under random load. Meanwhile, reliability index is obtained by using Second moment method and perturbation method. Based on the reliability design theory and sensitivity analysis method, torsion-bar is taken as an example, and the dynamic reliability sensitivity of torsion-bar is extensively discussed and a computing method is presented for dynamic reliability sensitivity design. The variation rules of dynamic reliability sensitivity are obtained and the effects of design parameters on reliability of torsion-bar are studied. As a result, the proposed method provides theoretical basis for reliability design of torsion bar.

Dynamic Reliability Sensitivity Design of Mechanical Components with Arbitrary Distribution Parameters

2011 ◽  
Vol 199-200 ◽  
pp. 487-494
Author(s):  
Xin Gang Wang ◽  
Bao Yan Wang ◽  
Li Sha Zhu ◽  
Hao Lu
Keyword(s):  
Theoretical Data ◽  
Computational Method ◽  
Design Parameters ◽  
Arbitrary Distribution ◽  
Random Load ◽  
Reliability Design ◽  
Dynamic Reliability ◽  
Reliability Sensitivity ◽  
Distribution Parameters ◽  
Mechanical Components

The variation rules of strength, load, and reliability of mechanical components are studied with a change in time, and a model is established for dynamic reliability of mechanical components under the random load acting. By combining the theory of reliability design with the method of sensitivity analysis, the computational method of dynamic reliability sensitivity design with arbitrary distribution parameter is proposed based on the methods Edgeworth and perturbation, and the problem of dynamic reliability sensitivity design of mechanical components distributed arbitrary distribution is solved as well as the variation rules of dynamic reliability sensitivity are given. The variation of reliability is studied as design parameters change a little, which provides theoretical data for dynamic reliability design of mechanical components.

scholarly journals Reliability models of belt drive systems under slipping failure mode

2017 ◽  
Vol 9 (1) ◽  
pp. 168781401668719 ◽  
Author(s):  
Peng Gao ◽  
Liyang Xie
Keyword(s):  
Failure Mode ◽  
Failure Rate ◽  
Dynamic Characteristics ◽  
Interference Model ◽  
Design Parameters ◽  
Belt Drive ◽  
Dynamic Reliability ◽  
Reliability Models ◽  
Sensitivity Functions ◽  
Drive Systems

Conventional reliability assessment and reliability-based optimal design of belt drive are based on the stress–strength interference model. However, the stress–strength interference model is essentially a static model, and the sensitivity analysis of belt drive reliability with respect to design parameters needs further investigations. In this article, time-dependent factors that contribute the dynamic characteristics of reliability are pointed out. Moreover, dynamic reliability models and failure rate models of belt drive systems under the failure mode of slipping are developed. Furthermore, dynamic sensitivity models of belt drive reliability based on the proposed dynamic reliability models are proposed. In addition, numerical examples are given to illustrate the proposed models and analyze the influences of design parameters on dynamic characteristics of reliability, failure rate, and sensitivity functions. The results show that the statistical properties of design parameters have different influences on reliability and failure rate of belt drive in cases of different values of design parameters and different operational durations.

Dynamic reliability-based robust optimization design for a torsion bar

2008 ◽  
Vol 223 (2) ◽  
pp. 483-490 ◽  
Author(s):  
X-G Wang ◽  
Y-M Zhang ◽  
B-Y Wang
Keyword(s):  
Robust Optimization ◽  
Optimization Design ◽  
Computational Method ◽  
Random Load ◽  
Dynamic Reliability ◽  
Reliability Sensitivity ◽  
Robust Optimization Design ◽  
Mechanical Components ◽  
Reliability Based Optimization ◽  
Torsion Bar

The variation rules of strength, load, and reliability of mechanical components are studied with a change in time, and a model is established for dynamic reliability of mechanical components under the random load acting. According to the model, the design of dynamic reliability sensitivity is discussed, and the approach to calculate it is proposed. By combining the theory of reliability-based optimization design with the method of sensitivity analysis, the computational method of dynamic reliability-based robust optimization design is established, and the problem of dynamic reliability-based robust optimization design of a torsion bar is solved.

Sign in / Sign up

Export Citation Format

Share Document