scholarly journals A New and Practical Reliability Allocation Method for a Complex System of NC Turrets

2019 ◽  
Vol 2019 ◽  
pp. 1-10
Author(s):  
Wei Hu ◽  
Fei Chen ◽  
Yankun Wang ◽  
Qunya Xie
Keyword(s):  
Complex System ◽  
Failure Modes ◽  
Expert Knowledge ◽  
Fault Tree ◽  
Complete Information ◽  
Design Stage ◽  
Reliability Allocation ◽  
Early Design ◽  
Early Design Stage ◽  
Allocation Method

Existing methods cannot satisfy the reliability allocation demands of the early design phase for the modern complex system of NC turrets. Motivated by the need of practical application, this paper proposes a new and practical reliability allocation method in the early design stage for NC turrets considering failure mode and system complexity, information inaccessibility, and expert knowledge limitation. First, the fault tree of a NC turret is quickly built to clear the relationship between the system’s compositions and failure modes up. Second, the happening probability of each failure event in the fault tree is firstly calculated by fuzzy expert evaluation to provide the reliability allocation with complete information. Third, by discussing the practical meaning of every layer in the fault tree, the proposed allocation strategy is within the experts’ knowledge scope for evaluating accurately. Eventually, the application result of the AK36100 A turret is presented and compared with some existing allocation methods, illustrating the rationality of the proposed allocation method.

scholarly journals A Comprehensive Method of Apportioning Reliability Goals for New Product of Hydraulic Excavator

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Wenting Liu ◽  
Qingliang Zeng ◽  
Lirong Wan ◽  
Chenglong Wang
Keyword(s):  
Real Life ◽  
Chemical System ◽  
Design Stage ◽  
Hydraulic Excavator ◽  
Effect Analysis ◽  
Reliability Allocation ◽  
Early Design ◽  
Construction Machinery ◽  
Early Design Stage ◽  
Fmea Method

It is important to allocate a reliability goal for the hydraulic excavator in the early design stage of the new system. There are some effective methods for setting reliability target and allocating its constituent subsystems in the field of aerospace, electric, vehicles, railways, or chemical system, but until now there is no effective method for the hydraulic excavator or engineering machinery. In this paper, an approach is proposed which combines with the conventional reliability allocation methods for setting reliability goals and allocating the subsystem and parts useful in the early design stage of the hydraulic excavator newly developed. It includes Weibull analysis method, modified Aeronautical Radio Inc. (ARINC) method, and modified systematic failure mode and effect analysis (FMEA) method. After completing reliability allocation, it is necessary to organize the designers and experts to evaluate the rationality of the reliability target through FEMA analysis considering feasibility of the improvement technically for the part which was new developed or had fault in its predecessor. The proposed approach provides an easy methodology for allocate a practical reliability goal for the hydraulic excavator capturing the real life behavior of the product. It proposes a simple and unique way to capture the improvement of the subsystems or components of the hydraulic excavator. The proposed approach could be extended to consider other construction machinery equipment and have practicality value to research excellent mechanical product.

Resilience Allocation for Early Stage Design of Complex Engineered Systems

2016 ◽  
Vol 138 (9) ◽  
Author(s):  
Nita Yodo ◽  
Pingfeng Wang
Keyword(s):  
Distribution System ◽  
Failure Modes ◽  
Early Stage ◽  
Design Stage ◽  
Early Design ◽  
Early Design Stage ◽  
Complex Engineered Systems ◽  
Operating Environments ◽  
Early Stage Design ◽  
Critical Components

The continuous pursuits of developing a better, safer, and more sustainable system have pushed systems to grow in complexity. As complexity increases, challenges consequently arise for system designers in the early design stage to take account of all potential failure modes in order to avoid future catastrophic failures. This paper presents a resilience allocation framework for resilience analysis in the early design stage of complex engineering systems. Resilience engineering is a proactive engineering discipline that focuses on ensuring the performance success of a system by adapting to changes and recovering from failures under uncertain operating environments. Utilizing the Bayesian network (BN) approach, the resilience of a system could be analyzed and measured quantitatively in a probabilistic manner. In order to ensure that the resilience of a complex system satisfies the target resilience level, it is essential to identify critical components that play a key role in shaping the top-level system resilience. Through proper allocation of resilience attributes to these critical components, not only target could resilience requirements be fulfilled, global cascading catastrophic failure effects could also be minimized. An electrical distribution system case study was used to demonstrate the developed approach, which can also be used as a fundamental methodology to quantitatively evaluate resilience of engineered complex systems.

Identification of Human Errors During Early Design Stage Functional Failure Analysis

2018 ◽  
Author(s):  
Lukman Irshad ◽  
Salman Ahmed ◽  
Onan Demirel ◽  
Irem Y. Tumer
Keyword(s):  
Failure Analysis ◽  
Human Error ◽  
System Level ◽  
Design Stage ◽  
Human Factors Engineering ◽  
Human Errors ◽  
Functional Failure ◽  
Early Design ◽  
Early Design Stage ◽  
Early Design Stages

Detection of potential failures and human error and their propagation over time at an early design stage will help prevent system failures and adverse accidents. Hence, there is a need for a failure analysis technique that will assess potential functional/component failures, human errors, and how they propagate to affect the system overall. Prior work has introduced FFIP (Functional Failure Identification and Propagation), which considers both human error and mechanical failures and their propagation at a system level at early design stages. However, it fails to consider the specific human actions (expected or unexpected) that contributed towards the human error. In this paper, we propose a method to expand FFIP to include human action/error propagation during failure analysis so a designer can address the human errors using human factors engineering principals at early design stages. To explore the capabilities of the proposed method, it is applied to a hold-up tank example and the results are coupled with Digital Human Modeling to demonstrate how designers can use these tools to make better design decisions before any design commitments are made.

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