A Comprehensive Optimum Design Method of Monitorability-based Design for Mechanical System Using Collaborative Theory

Abstract: The study aims to investigate the mechanical system optimum design based on collaborative theory. Due to the complexity of the modern machinery, mechanical systems are readily to damage when unexpected failures occur on important components. It is therefore, critical to monitor the machine state for preventing the impending faults. The key issues to realize the feasible and reliable mechanical condition monitoring is information acquisition, which relies on the available design of the detection devices. Literature review indicates that an extensive attention has been put on the so called Monitorability in the systematic design of mechanical systems. Monitorability is emphasized that in the original design of mechanical systems one should consider available information acquisition property. Moreover, monitorability-based design is known as a design attribute of mechanical system worldwide. However, less work has been done in this field. In this study, a novel method based on collaborative theory is proposed for the monitorability design. The connotation and application of collaborative theory for monitorability design are discussed in details. The information synergy model and organization framework of monitorability-based design are established by using computer technology and network technology. The experiments demonstrate the effectiveness of the proposed monitorability design system for a more powerful optimum design of mechanical systems and show a promising future for the industrial applications

Recent Progress on Mechanical Condition Monitoring and Fault Diagnosis

AbstractMechanical equipments are widely used in various industrial applications. Generally working in severe conditions, mechanical equipments are subjected to progressive deterioration of their state. The mechanical failures account for more than 60% of breakdowns of the system. Therefore, the identification of impending mechanical fault is crucial to prevent the system from malfunction. This paper discusses the most recent progress in the mechanical condition monitoring and fault diagnosis. Excellent work is introduced from the aspects of the fault mechanism research, signal processing and feature extraction, fault reasoning research and equipment development. An overview of some of the existing methods for signal processing and feature extraction is presented. The advantages and disadvantages of these techniques are discussed. The review result suggests that the intelligent information fusion based mechanical fault diagnosis expert system with self-learning and self-updating abilities is the future research trend for the condition monitoring fault diagnosis of mechanical equipments

Borehole Electromagnetic Method for Exploration of Coal Mining Goaf

Due to severe harms of goaf collapse, the goaf exploration and governance has become an urgent issue for protecting the normal life of local people. According to the coal mine geology, different geo-electrical models have been employed for the purpose of discovering the goafs. However, most existing methods require a large amount of computation consumption. In order to address this issue, a forward numerical simulation using the borehole electromagnetic method has been developed in this work to explore the coal mining goafs. The innovation of this method is that the computation consuming can be saved significantly. Numerical simulation demonstrates high effectiveness of the borehole electromagnetic method in coal mining goaf exploration. Therefore, this research provides a new idea for exploring the coal mine goafs by geophysical method

Maxwell-Equations Based on Mining Transient Electromagnetic Method for Coal Mine-Disaster Water Detection

Water-bearing geological structure is a serious threat to coalmine safety. This research focuses on detecting water-bearing geological structure by transient electromagnetic method. First, we introduce the principle of mining transient electromagnetic method, and then explain the technique of Finite Different Time Domain using in the transient electromagnetic method. Based on Maxwell equations, we derive the difference equations of electromagnetic field and study the responses of water-bearing geological structure using FDTD. Moreover, we establish the relationship between receiving electromagnetic field and geological information. The typical coal geological model of goaf-water is chosen to do the numerical simulation. Besides, we verify the availability of the method by numerical simulation using coal geological model. Finally, we use the method in the coalmine which is located in Linfen city in Shanxi province in China, and the detecting result is verified by drilling

Wear Mechanism of Artificial Joint Failure Using Wear Debris Analysis

Aseptic loosening is one of the main failure modes in artificial joints. Significant information about the aseptic loosening is carried by the wear debris of the joints. In this paper, the wear debris acquired from the ultrahigh molecular weight polyethylene (UHMWPE) artificial joints is prepared and a systematic research is carried out to investigate the wear mechanism of aseptic loosening using the wear debris analysis. The hip joint simulator was used to conduct the wear tests of the CoCrMo-UHMWPE artificial joint friction pairs. The scanning electron microscope (SEM) was employed to analyze the wear debris profiles. The analysis results demonstrated that the UHMWPE joints mainly produced the roundness, tuberous, lacerated, sheet, pole-liked and strip wear debris, and the wear mechanism of the joint aseptic loosening had a close relationship with the morphology of the debris types. The adhesive wear, fatigue wear and laceration under alternating stress were the main causes of the joint failure. Based on the wear debris analysis results, a new diagnosis method using the radar map fractal representation was proposed to diagnose the failure of the artificial joints