Influence of Roof Rock Thickness on the Failure Probability of Thermally Stable Diamond Composite Rock Cutting Tips

2021 ◽  
Vol 878 ◽  
pp. 98-103
Author(s):  
Yong Sun ◽  
Xing Sheng Li ◽  
Hua Guo
Keyword(s):  
Failure Probability ◽  
Failure Modes ◽  
Roof Rock ◽  
Cutting Temperature ◽  
Rock Cutting ◽  
Estimation Accuracy ◽  
Thermally Stable ◽  
Diamond Composite ◽  
Sudden Failure ◽  
Underground Coal Mines

Thermally Stable Diamond Composite (TSDC) has been used to make rock cutting tips to tackle the challenges of high cutting temperature and high abrasiveness met in hard rock cutting. Various research has been conducted to investigate the failure behaviour and predict the failure risk of the TSDC tips in real rock cutting operations. Based on the scenario of roadway development in underground coal mines, a series studies have been carried out to estimate the probability of TSDC tip sudden failure suffered from randomly occurring excessive bending force, which is one of major failure modes of the TSDC tips. This study aims to improve estimation accuracy of the failure probability by removing the constraint on roof rock thickness that has been adopted in existing research.

Failure Probability of Thermally Stable Diamond Composite Tips for Cutting Rock Segments

2018 ◽  
Vol 936 ◽  
pp. 192-197 ◽  
Author(s):  
Yong Sun ◽  
Xing Sheng Li
Keyword(s):  
Failure Probability ◽  
Rock Cutting ◽  
Estimation Accuracy ◽  
Segment Length ◽  
High Wear Resistance ◽  
Failure Behavior ◽  
Thermally Stable ◽  
Diamond Composite ◽  
The Impact

Thermally Stable Diamond Composite (TSDC) tips have attracted a great attention of rock cutting industry due to the higher thermal stability and high wear resistance of TSDC. To make the TSDC tipped picks practical for real application, it is important to understand the failure behavior of the TSDC tips for rock cutting. One of the failure characters of TSDC tips is random failures. In this paper, a method is proposed to calculate the failure probability of TSDC tips for cutting individual rock segments. This method enables to link the segment length to the failure probability of the tip for cutting the segment. A numerical case study is presented to validate the method. The method can effectively reduce the impact of the number of segments on failure probability estimation accuracy.

scholarly journals Failure Probability Prediction of Thermally Stable Diamond Composite Tipped Picks in the Cutting Cycle of Underground Roadway Development

2019 ◽  
Vol 9 (16) ◽  
pp. 3294 ◽  
Author(s):  
Yong Sun ◽  
Xingsheng Li ◽  
Hua Guo
Keyword(s):  
Failure Mode ◽  
Failure Probability ◽  
Probabilistic Approach ◽  
Rock Cutting ◽  
Current Approach ◽  
Thermally Stable ◽  
Diamond Composite ◽  
Extended Approach ◽  
Probability Prediction ◽  
Improved Accuracy

The Thermally Stable Diamond Composite (TSDC) tipped pick has been developed to replace Tungsten Carbide (WC) tipped picks for hard rock cutting. Due to the material properties of TSDC, a major failure mode of TSDC tipped picks during rock cutting is random failures caused by excessive bending force acting on the cutting tips. A probabilistic approach has been proposed to estimate the failure probability of picks with this failure mode. However, there are two limitations in existing research: only one drum revolution is considered, and the variation of rock thickness is ignored. This study aims to extend the current approach via removing these limitations, based on the failure probability analysis of picks over a full cutting cycle in the underground coal mining roadway development process. The research results show that both drum advance direction and the variation of rock thickness have significant impacts on pick failure probability. The extended approach can be used to estimate pick failure probability for more realistic scenarios in real applications with improved accuracy. Although the study focused on TSDC tipped picks, the developed approach can also be applied to other types of picks.

A Simplified Approach to the Failure Probability Assessment of Thermally Stable Diamond Composite Rock Cutting Tips

2020 ◽  
Vol 976 ◽  
pp. 62-68
Author(s):  
Yong Sun ◽  
Xing Sheng Li ◽  
Hua Guo
Keyword(s):  
Failure Probability ◽  
Rock Cutting ◽  
High Wear Resistance ◽  
Failure Behavior ◽  
Thermally Stable ◽  
Diamond Composite ◽  
Simplified Approach ◽  
Cutting Length ◽  
Numerical Case Study

Thermally Stable Diamond Composite (TSDC) has high thermal stability and high wear resistance, and hence is potential to be used as cutting tips for hard rock cutting. Understanding the failure behavior of the TSDC tips during practical rock cutting is a key to enable the TSDC cutting tips to be applied successfully in mining and construction industries. Previous research has shown that the character of random failures due to excessive bending force on TSDC tips is of a major concern, and an approach to estimation of the failure probability of TSDC tips for cutting a rock segment has been developed. However, this approach requires the acquisition of the total cutting length of rock by a tip since it is brand new to it is failed, which can limit the application of the approach. In this paper, a simplified approach is proposed and compared with the existing approach through a numerical case study.

Towards Improving Rock Cutting Tools Using Thermally Stable Diamond Composites

2009 ◽  
Vol 76-78 ◽  
pp. 585-590 ◽  
Author(s):  
Habib Alehossein ◽  
Xing S. Li ◽  
Jim N. Boland
Keyword(s):  
Metal Cutting ◽  
Cutting Tools ◽  
Rock Cutting ◽  
Successful Implementation ◽  
Geometrical Shape ◽  
Dimension Stone ◽  
Thermally Stable ◽  
Simple Material ◽  
Diamond Composite ◽  
Tool Replacement

Industrial application of synthetic diamond ceramics is growing very fast due to their super hardness, superb wear resistance and long-life durability. In rock, concrete and metal cutting, drilling, mining and quarrying and dimension stone industries, cutting tools made of diamond composites or impregnated diamond composite segments are gradually replacing the more commonly used cemented tungsten carbide (WC) tools. Through its SMARTCUT research program, CSIRO in the past 15 years has developed harder and stronger thermally stable diamond composite (TSDC) drag picks to encourage and help manufacturing and mining industries improve their cutting performance by replacing these traditional WC cutting tools with the new revolutionary TSDC tools. This improvement process however is much more complex than a simple material or cutting tool replacement, since the mechanism and configuration of cutting are substantially different in the two cutter head systems and its successful implementation requires a better understanding of the basics of rock cutting. Some of the factors influencing the differences are: cutter wear, fracture toughness, compressive and tensile strength, thermal properties, geometrical shape, spacing, angle of attack, rake angle, sharpness and bluntness characteristics, lacing design and cutter arrangements. Besides, it is most important to understand the relation between the tool or tool force and the fragmentation of the rock, which is the main focus of this paper.

scholarly journals Mechanism reliability and sensitivity analysis of landing gear under multiple failure modes

2021 ◽  
Vol 39 (1) ◽  
pp. 46-54
Author(s):  
Changcong Zhou ◽  
Mengyao Ji ◽  
Yishang Zhang ◽  
Fuchao Liu ◽  
Haodong Zhao
Keyword(s):  
Failure Probability ◽  
Failure Modes ◽  
Kriging Model ◽  
Landing Gear ◽  
Multiple Failure Modes ◽  
Analysis And Design ◽  
Extension System ◽  
Extension Mechanism ◽  
Assembly Error ◽  
Adaptive Kriging

For a certain type of aircraft landing gear retraction-extension mechanism, a multi-body dynamic simulation model is established, and the time-dependent curves of force and angle are obtained. Considering the random uncertainty of friction coefficient, assembly error, and the change of hinge wear under different retraction times, the reliability model is built including three failure modes of landing gear, i.e. blocking failure, positioning failure and accuracy failure. Based on the adaptive Kriging model, the reliability and sensitivity of retraction-extension system under the condition of single failure mode and multiple failure modes in series are analyzed, and the rule of reliability and sensitivity changing with the number of operations is given. The results show that the system failure probability of landing gear mechanism tends to decrease first and then increase when considering the given information of random factors, and the influences of random factors on the failure probability vary with the number of operations. This work provides a viable tool for the reliability analysis and design of landing gear mechanisms.

Cutting force as an index to identify the ductile-brittle failure modes in rock cutting

2021 ◽  
Vol 146 ◽  
pp. 104834
Author(s):  
Xianwei Dai ◽  
Zhongwei Huang ◽  
Huaizhong Shi ◽  
Xiaoguang Wu ◽  
Chao Xiong
Keyword(s):  
Cutting Force ◽  
Brittle Failure ◽  
Failure Modes ◽  
Rock Cutting

scholarly journals OPTIMIZING BREAKWATER DESIGN CONSIDERING THE SYSTEM OF FAILURE MODES

2011 ◽  
Vol 1 (32) ◽  
pp. 37
Author(s):  
Alvaro Campos ◽  
Carmen Castillo ◽  
Rafael Molina
Keyword(s):  
Design Process ◽  
Failure Probability ◽  
Failure Modes ◽  
Optimization Techniques ◽  
Physical Interaction ◽  
Complete Knowledge ◽  
Potential Failure

Optimization techniques have been applied to breakwater design in order to automate the design process (Castillo et al. 2004, 2006). Since safety of structures is the fundamental criterion for design, a complete knowledge of the potential failure modes, as well as the possible interaction between them, is essential to provide a consistent design. Failure modes are correlated in two ways: through common parameters like HS or by physical interaction. The latter has not yet been precisely identified nor quantified. The aim of the present paper is to advance on the analysis of both types of correlations and to check how the combination of failure modes modifies the failure probability of the whole structure either increasing or decreasing it. An application to a special type of composite breakwater is proposed: the fuse parapet case, where part of the parapet fails under certain circumstances in order to ensure the whole stability of the caisson, despite increasing overtopping events.

A global sensitivity analysis approach for multiple failure modes based on convex-probability hybrid uncertainty

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yidu Zhang ◽  
Yongshou Liu ◽  
Qing Guo
Keyword(s):  
Failure Probability ◽  
Failure Modes ◽  
Sensitivity Index ◽  
System Failure ◽  
Multiple Failure Modes ◽  
Content Type ◽  
Global Sensitivity ◽  
Sensitivity Indices ◽  
Independent Variable ◽  
Hybrid Uncertainty

Purpose This paper aims to develop a method for evaluating the failure probability and global sensitivity of multiple failure modes based on convex-probability hybrid uncertainty. Design/methodology/approach The uncertainty information of the input variable is considered as convex-probability hybrid uncertainty. Moment-independent variable global sensitivity index based on the system failure probability is proposed to quantify the effect of the input variable on the system failure probability. Two-mode sensitivity indices are adopted to characterize the effect of each failure mode on the system failure probability. The method based on active learning Kriging (ALK) model with a truncated candidate regions (TCR) is adopted to evaluate the systems failure probability, as well as sensitivity index and this method is termed as ALK-TCR. Findings The results of five examples demonstrate the effectiveness of the sensitivity index and the efficiency of the ALK-TCR method in solving the problem of multiple failure modes based on the convex-probability hybrid uncertainty. Originality/value Convex-probability hybrid uncertainty is considered on system reliability analysis. Moment-independent variable sensitivity index based on the system failure probability is proposed. Mode sensitivity indices are extended to hybrid uncertain reliability model. An effective global sensitivity analysis approach is developed for the multiple failure modes based on convex-probability hybrid uncertainty.

Characterization of Thermally Stable Diamond Composite Material

2014 ◽  
Vol 777 ◽  
pp. 165-170 ◽  
Author(s):  
Vladimir Luzin ◽  
James Boland ◽  
Maxim Avdeev ◽  
Xing Li
Keyword(s):  
Phase Distribution ◽  
Cutting Tools ◽  
Mining Industry ◽  
Polycrystalline Diamond ◽  
Wear Test ◽  
Stability Field ◽  
Binder Phase ◽  
Thermally Stable ◽  
Graphite Phase ◽  
Diamond Composite

Diamond composite materials are being used increasingly in cutting tools for both the mining and manufacturing industries. Except for the low pressure CVD and SPS methods, most SiC based diamond composites are produced under high pressure and high temperature (HPHT). The dominant binder phase is SiC and these composites are classed as thermally stable and are referred to as TSDC (thermally stable diamond composite). TSDC composites are produced by reactive sintering either within the diamond stability field, ~1500°C and ~5.5 GPa, or in the graphite phase field at ~1550°C and ~2 - 3.5 GPa as originally patented by Ringwood. Unlike the traditional polycrystalline diamond composite (PCD) that use Co as the binder phase and operate under restricted temperature conditions, usually less the 800°C, TSDC is Co-free allowing the operational temperature range for TSDC to be extended substantially. Extensive experimental research has been conducted at the CSIRO (Commonwealth Scientific & Industrial Research Organization) Rock Cutting Laboratory to assess the quality of TSDC products through a series of in-house tests that have been developed (abrasive wear test, compressive and shear testing) to facilitate their use in the mining industry. The focus is to prevent TSDC from premature failures in drilling and cutting operations. Since the wear resistance and performance in general, of TSDC cutting elements are strongly dependent on the phase composition, phase distribution (microstructures) and phase interaction (microstresses), detailed studies of TSDC have been undertaken using optical, SEM (with EDS and CL), Raman microscopy and radiographic imaging of macro defects as well as x-ray and neutron diffraction. Residual stress measurements were made using the neutron diffractometer Kowari at OPAL research reactor in the diamond and SiC phases in two TSDC samples. The microstresses that developed in these phases as a result of quenching from high sintering pressure and temperature and the mismatch of the thermo-mechanical properties of SiC matrix and diamond inclusions were evaluated. The matrix-inclusion concept has also been used to calculate stress partition in the phases of the TSDC products that can be directly comparable with the experimental data and give clearer interpretation of the experimental results.

The Wear of Thermally Stable Diamond During Rock Cutting

1994 ◽  
Vol 116 (4) ◽  
pp. 268-272 ◽  
Author(s):  
G. Cooper ◽  
Z. Liu ◽  
M. Yang
Keyword(s):  
Cutting Forces ◽  
Cutting Speed ◽  
Power Input ◽  
Rock Cutting ◽  
Cutting Conditions ◽  
Depth Of Cut ◽  
Thermally Stable ◽  
Cutting Experiments

Single-cutter experiments have been performed to investigate the cutting and wear of thermally stable diamond (SYNDAX3) during rock cutting. Cutting forces increase linearly with depth of cut, but are unaffected by cutting speed. The wear of the cutter per mass of rock removed is found to decrease with increasing depth of cut. Excessive cutting speed is harmful to the cutter since both the cutter temperature and the change in cutter temperature per power input increase with cutting speed. In the cutting experiments, evidence of delayed fracturing is observed. For essentially constant cutting conditions, fractures develop in the cutter only after a significant amount of cutting is done. Damage of this type is very harmful to the cutter as cutter temperature rises and efficiency drops with increasing wear.

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