The study on Reliability Design of Knotter Cam Gear of D-knotter

This paper explores the grey model based PSO (particle swarm optimization) algorithm for anti-cauterization reliability design of underground pipelines. First, depending on underground pipelines’ corrosion status, failure modes such as leakage and breakage are studied. Then, a grey GM(1,1) model based PSO algorithm is employed to the reliability design of the pipelines. One important advantage of the proposed algorithm is that only fewer data is used for reliability design. Finally, applications are used to illustrate the effectiveness and efficiency of the proposed approach.

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Reliability-Based Design Optimization for Nonlinear Energy Harvesters

Volume 2: Integrated System Design and Implementation; Structural Health Monitoring; Bioinspired Smart Materials and Systems; Energy Harvesting ◽

10.1115/smasis2015-8884 ◽

2015 ◽

Author(s):

Sumin Seong ◽

Christopher Mullen ◽

Soobum Lee

Keyword(s):

Energy Harvesting ◽

Design Optimization ◽

Reliability Based Design Optimization ◽

Vibration Energy Harvester ◽

Reliability Design ◽

Energy Harvesters ◽

Reliability Based Design ◽

Stable Characteristic ◽

Tip Mass ◽

Nonlinear Energy

This paper presents reliability-based design optimization (RBDO) and experimental validation of the purely mechanical nonlinear vibration energy harvester we recently proposed. A bi-stable characteristic was embodied with a pre-stressed curved cantilever substrate on which piezoelectric patches were laminated. The curved cantilever can be simply manufactured by clamping multiple beams with different lengths or by connecting two ends of the cantilever using a coil spring. When vibrating, the inertia of the tip mass activates the curved cantilever to cause snap-through buckling and makes the nature of vibration switch between two equilibrium positions. The reliability-based design optimization study for maximization of power density and broadband energy harvesting performance is performed. The benefit of the proposed design in terms of excellent reliability, design compactness, and ease of implementation is discussed. The prototype is fabricated based on the optimal design result and energy harvesting performance between the linear and nonlinear energy harvesters is compared. The excellent broadband characteristic of the purely mechanical harvester will be validated.

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Gradual Reliability Sensitivity Analysis of Mechanical Part Considering Preventive Maintenance

Advances in Mechanical Engineering ◽

10.1155/2014/829850 ◽

2014 ◽

Vol 6 ◽

pp. 829850

Author(s):

Li Changyou ◽

Liu Haiyang ◽

Guo Song ◽

Zhang Yimin ◽

Li Zhenyuan

Keyword(s):

Mechanical System ◽

Preventive Maintenance ◽

Gamma Process ◽

Reliability Model ◽

Application Process ◽

Initial State ◽

Reliability Design ◽

Mechanical Part ◽

Safety And Reliability ◽

Deterioration Process

A lot of mechanical parts are subject to failure due to the deterioration. Usually the preventive maintenance is taken to ensure the safety and reliability. Therefore, it is very important to study the gradual reliability design of the mechanical part for improving the gradual reliability of the mechanical system under the condition of considering the preventive maintenance. Beta distribution is employed to describe the randomness of the mechanical part state after the preventive maintenance. The deterioration process of the mechanical part is modeled using the nonstationary Gamma process. The gradual reliability model before the first preventive maintenance is proposed according to the gradual failure principle and using the initial state distribution and the properties of Gamma process. Then, the gradual reliability model between any two times of preventive maintenance is also derived. Subsequently, the sensitivity equations of the proposed gradual reliability model to each parameter are given. The application process and practicality of the proposed approach are described by a numerical example. This work solved the problem where the maintenance has not been well considered in the reliability design of the mechanical part and contributed to the theory and method of improving the safety and reliability operation of the mechanical system.

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