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Conical picks are applied to rock breaking, and the cutting parameters greatly influence cutting performance and rock damage. A conical pick rock-cutting numerical simulation model and software to provide a quantitative analysis of rock damage are established to research the influence of cutting parameters on cutting force and rock damage. The research results indicated that the average peak cutting force decreases with an increased cutting angle, and the average peak cutting force increases with a decreased cutting speed. The average peak cutting force of the second conical pick increases as the distance between double conical picks increases in the process of rock-cutting with double conical picks. There is a positive correlation between the volume of rock damage, the volume of rock breaking, and the cutting force of the conical pick. The research results provide a reference for optimizing the cutting parameters of conical picks. [ABSTRACT FROM AUTHOR]

Circular saw blades are widely used in stone processing. The circular saw blade cutting hard rock numerical simulation model based on ANSYS/LS-DYNA was established to investigate the complex dynamic problem in rock cutting. The failure mechanism of the rock and the influence of cutting parameters on the cutting force and rock fragments were studied by numerical simulation. The results demonstrated that the failure modes of the rock were mainly tensile failure with some shear failure and compressive failure. The cutting force and the number of fragments increased with the feed speed. With the increasing circular saw blade rotational speed, the cutting force and the number of fragments decreased and tended to stabilize. With the distance between the circular saw blades increasing, the cutting force and rock fragments number increase and then maintain basic stability, and when the distance between double circular saw blades reaches 25 mm, it will form a completed rock plate and the interaction of circular saw blades will decrease. The numerical simulation can accurately simulate rock breakage and force when a circular saw blade cuts rock. [ABSTRACT FROM AUTHOR]

The conical pick is the most crucial tool of roadheader for breaking rock, establishing the conical pick cutting rock and conical pick fatigue life numerical simulation models to investigate the influence of cutting parameters on rock damage, average peak cutting force, specific cutting energy and the conical pick fatigue life. The research results indicate that the width and depth of rock damage increase with increasing cutting depth and cutting speed. The average peak cutting force and the specific cutting energy have the same changing tendency. The changing trend of conical pick fatigue life and conical pick stress is opposite relationship. The optimum cutting angle of the conical pick cutting rock is 45°. Applying the research results for guiding the optimization of the cutting parameters reduces the specific cutting energy and stress and improves the conical pick fatigue life. [ABSTRACT FROM AUTHOR]

The diamond sawblade has been widely used in the field of rock mining and processing. This article, through the establishment of a numerical simulation model of diamond sawblade cutting rock, studies the influence of the distance between the diamond sawblade and free surface on cutting performance. In the process of diamond sawblade cutting rock, with the increase of the distance from the sawblade to the free surface, the average cutting force, normal force, and tangential force of the sawblade increase at first and then stabilize, and the axial force gradually decreases and tends to be stable. In the process of cutting rock with fixed depth, cutting force and rock damage are positively related to feed speed and cutting depth of the diamond sawblade. Through the statistical analysis of rock damage by image recognition program statistics, it is concluded that the feed speed and cutting depth of the sawblade have a significant impact on the rock damage value. When the distance increases to 12 mm, there is a relatively complete rock plate between the sawblade and free surface. The rock free surface damage disappears when distance reaches 16 mm. The research results provide a theoretical basis for the sawblade processing rock plate. [ABSTRACT FROM AUTHOR]

The new method of rock breaking based on the combination of circular sawblade and conical pick was proposed to improve the effectiveness of hard rock breaking. The numerical simulation method was applied to research the conical pick cutting arc rock plate by ANSYS/LS-DYNA. The conical pick cutting arc rock plate numerical simulation model was established to research the influence of arc rock plate structural parameters and cutting parameters on cracks formation and propagation of the arc rock plate and the cutting force in the process of conical pick cutting arc rock plate. The amount of cracks is positively correlated with arc rock plate thickness, the cutting speed, and distance of cutting point to arc rock plate central axis and negatively correlated with the cutting angle. The mean peak cutting force is positively correlated with the thickness of arc rock plate and the distance of cutting point to arc rock plate central axis; however, it is negatively correlated with the arc rock plate height and width and cutting angle of conical pick. The simulation results can be used to predict the conical pick work performance with various cutting parameters and structural parameters. [ABSTRACT FROM AUTHOR]

Conical pick wear is an urgent problem in the roadway excavation caused by hard rock difficult to break. The traditional method of increasing cutting power to improve cutting performance of conical pick significantly increases pick wear. In the paper, a saw blade and conical pick combined cutting method is proposed based on increased free surface. To research the fracture morphology and cutting force of rock plate, theoretical, numerical, and experimental methods are used. By theoretical research, the bending mechanical model of rock plate bending is established. The cutting position and the junction between the free sides and fixed sides are preferentially broken. A numerical model combining the erosion and damage constitutive model is built, and the cutting process of rock plate was presented. According to rock plate experiment, the peak cutting force increases with the increasing uniaxial compressive strength, thickness of rock plate, and cutting depth of conical pick and decreases with the increasing width and height of rock plate. Exponential relationships exist between peak cutting force and thickness, width and height of rock plate, and cutting depth of conical pick. Linear relationship exists between peak cutting force and uniaxial compressive strength. The size of rock fragments increases with uniaxial compressive strength, width, and height of rock plate. [ABSTRACT FROM AUTHOR]

The rock cutting process with a circular sawblade and the rock breaking mechanism of rock are studied with a numerical simulation method in this paper. The influence of cutting parameters of the circular sawblade on cutting force, rock damage, and specific cutting energy in the process of circular sawblade cutting rock is researched. The cutting force increases with the feed speed and an increase in cutting depth and decline in rotation speed. Cutting rock with double circular sawblades can reduce cutting force. However, the specific cutting energy declines with the increase in cutting depth and the decline in the distance between the double circular sawblades. Cutting parameters have a great influence on the damage range of rock. The research results can be applied to rock processing with a circular sawblade. [ABSTRACT FROM AUTHOR]

Conical pick is a rock cutting tool that is commonly used in roadway driving. Pick wear frequently happens in the course of breaking hard rock. The current paper shows a new method to solve the problem of pick wear. The rock is preslit with the saw blade and then broken by the conical pick. In order to study the cutting force and features of rock fragment, the numerical model is built between rock plate and conical pick. And element erosion is added in the code to obtain the fracture result. The rock plate cutting testbed is made to testify the correctness of numerical simulation. The width, height, and thickness of the rock plate, as well as cutting angle and cutting position, which influence cutting force and rock fracture are studied. According to the results, there exist exponential relationships between cutting force and width and thickness of rock plate. In addition, a linear relationship is found between the cutting force and the height of rock plate. Furthermore, both the cutting angle and cutting depth have an influence on cutting force. In particular, the factors of thickness and height or rock plate have the most obvious influence on cutting force. It is proven that what is beneficial to rock fracture is higher height and lower thickness of rock plate. [ABSTRACT FROM AUTHOR]

Conical pick is a diffusely applied cutting tool in rock excavation in the coal-mining industry. In order to enhance the capability of conical pick, a new rock cutting method based on increased free surface is proposed. To research the peak cutting force and fracture morphology, ANSYS/LS-DYNA is used to establish the conical pick and rock interaction model. To obtain the fracture morphology of rock plate, eroding contact, erosion element failure, and damage constitutive are considered in the numerical model. Mechanical properties test and rock plate cutting experiment are carried out to guarantee and verify the correctness of the numerical model. The width and height of rock plate influencing peak cutting force and fracture morphology are studied, and the stable peak cutting force is defined. Lower width and height contribute to more fragments in smaller dimension produced during the rock plate cutting process. Besides, higher skew angle leads to more fragments. The peak cutting force decreases with the increasing width and height of rock plate while reaching stable peak cutting force, and it reduces and then remains stable with the increasing cutting position and symmetrical with skew angle of zero degree. [ABSTRACT FROM AUTHOR]

In the rock cutting process, conical pick wear is often encountered. In order to restrain this condition, a saw blades and conical pick combined cutting method was put forward. Saw blades were employed to slit the rock for increasing the free surface, and then the conical pick was used to break the rock. To research the cutting performance of the new cutting method, the corresponding experimental device and a three-dimensional finite element model are established. In order to obtain crack propagation and fragment separation and to study the fracture process of the rock plate, a damage constative model and failure mechanism were combined in the numerical model. The mechanical tests were carried out to achieve the mechanical parameters of the rock. To investigate different parameters affecting rock plate cutting performance, experiments with different compressive strengths, physical parameters, and cutting depths were carried out. Moreover, the confining pressures affecting the cutting performance were adopted to simulate deep mining conditions. The experimental results demonstrated that the peak cutting force shows the exponential positive correlation with compressive strength, thickness of the rock plate, and cutting depth of the conical pick, and exhibits the exponential positive correlation with rock plate height and width. Besides, the numerical simulation results show that peak cutting force and confining pressure have a binomial relationship. [ABSTRACT FROM AUTHOR]

Aiming at the complex nonlinear dynamic problem of cutting hard rock with diamond sawblades, the process of hard rock cutting with a diamond sawblade was studied based on ANSYS/LS-DYNA. A numerical simulation model of a diamond sawblade cutting hard rock with different rotation speeds, feed speeds, and cutting depths was established to study the effects of the cutting parameters on the cutting force and specific cutting energy consumption and on the damage to the rock. The numerical simulation results demonstrated that the feed speed and cutting depth of the diamond saw are quadratically correlated with the cutting force, but the rotation speed is negatively linearly correlated. The damage region of the rock is positively correlated with the feed speed and cutting depth of the diamond sawblade and has a negative correlation with the rotation velocity. The cutting parameters have a great influence on specific cutting energy consumption. Analysis of the relationship among the cutting parameters and the specific cutting energy with multivariate linear fitting indicated that the cutting speed and cutting depth have a great influence on the cutting energy. [ABSTRACT FROM AUTHOR]

In order to overcome conical pick wear in the traditional rock cutting method, a new cutting method was proposed on account of increasing free surface of the rock. The mechanical model of rock plate bending under concentrated force was established, and the first fracture position was given. The comparison between experimental and numerical results indicated that the numerical method is effective. A computer code LS-DYNA (3D) was employed to study the cutting performance of a conical pick. To study the rock size influenced on the cutting performance, the numerical simulations with different thickness, width, and height of a rock plate was carried out. The numerical simulation with the different cutting parameters of cutting speed, cutting angle, and cutting position influenced on cutting performance was also carried out. The numerical results indicated that the peak force increased with the increasing thickness of rock plate. With the increasing width and height of the rock plate, the peak force decreased and then became stable. Besides, the peak force decreased with the increasing of cutting position lxp/lx. Moreover, the peak force increased and then decreased with the increasing of cutting angle. The cutting speed has nonsignificant influence on the peak force. The strong exponential relationship was obtained between the peak force and cutting position, thickness, height, and width of the rock plate at a confidence level of 0.95. A binomial relationship was observed between the peak force and cutting angel. The cutting force comparison between traditional rock cutting and rock plate cutting indicated that the new cutting method can effectively reduce peak cutting force. [ABSTRACT FROM AUTHOR]