A bondedparticle model for cemented sand request pdf. Aug 28, 2014 bonded particle model bpm is widely used to model geomaterials, in which calibration against the results from uniaxialtriaxial compressive tests, brazilian tensile tests and shear tests have been commonly conducted. Crack initiation in uniaxial compressive loading of rocks occurs well before the peak strength is reached. North america global cement bonded particle board market by application. A comparison between 2d and 3d bondedparticle models for rock. It should be noted that many bonded particle models 1,24 25 262728 are available in dem to model cohesive grainbased materials. The microscopic properties of particles and bonds in the model are calibrated.
Realization of optional method of determining the concretes. Omniroc leads the industry in offering innovative safe, affordable, noncombustible cement bonded particle board cbpb for firerated roofs, floors and walls for schools, nursing homes, hospitals, elderly housing, residential, multifamily dwellings, daycare centers and other commercial buildings. Metodo dos elementos discretos, bonded particle model, rocha, cimentacao, resistencia abstract. To calibrate both models, a new standard procedure was developed. In order to study coal cutting mechanism, particle discrete element theory is adopted to establish numerical modeling of coal cutting processes. The differences between the cement bonded particle panel and other construction panels are the result of its composition, the mixture ratios of wood and cement and the manufacturing process. Before mimicking the chemical corrosion processes using the pcc model in dem, laboratory chemical corrosion tests on limestone are first conducted to investigate the micro damage evolution using nuclear. The bpm represents rock by a dense packing of nonuniformsized circular or spherical particles that are bonded together at their contact points and whose mechanical behavior. Bondedparticle model with nonlinear elastic tensile stiffness for rock like materials article pdf available in applied sciences 77. International journal of rock mechanics and mining sciences 41 8. The bondedparticle model bpm consisting of parallelbonded disks or spheres suffers from the limitation that if one matches the unconfinedcompressive strength of a typical hard rock, then the directtension strength of the model will be too large. Although studies on the failure mode of intermittent rock joint abound, the improvements still are expected. For these reasons, the pb model was used in our study and applied to all the pfc modeling discussed in this paper.
Crack initiation, propagation and coalescence in rocklike. King jams with slash and others 66 live at the royal albert hall 2011 duration. A computational methodology is described for simulating inelastic deformation and fracture of rock in which a densely packed assembly of arbitrarily sized circular particles bonded together at their contact points represents the rock using the distinctelement code pfc 2d itasca, 1995a. Canadian geotechnical journal canadian science publishing. However, these calculation methods with their definite physical. The beginner shuffle pattern for rock, blues, country. A bonded particle model of lithophysal tuff has been used. The offered method is based on measurement of long strength by nondestructive method, based onacoustic issue.
Cracking processes in rocklike material containing a. The bondedparticle model as a tool for rock mechanics. Bonded particle model bpm for rock for the simulation of in tact rock behavior potyondy and cundall, 2004, and discret e fracture network dfn modelling. Naprotechnology relies on the creighton model fertilitycare system crms biomarkers to monitor easily and objectively the occurrence of. Pfc2d simulates the material by representing it as an assembly of circular particles that can be bonded to one another, hence forming a bonded particle assembly. Pfc simulation of crack evolution and energy conversion during. We generalize our view of a bondedparticle model bpm to consist of a base material that is a packed assembly of rigid grains joined by deformable and breakable cement at graingrain contacts to which largerscale joints can be added and whose mechanical behavior is simulated by the distinctelement method using the two and threedimensional discontinuum programs pfc2d and. Us6303234b1 process of using sodium silicate to create. In this study, bondedparticle models were used to simulate the intact rock behavior of westerly granite. In this paper, numerical simulation using a bondedparticle model was undertaken to provide a better understanding of the mechanism of microwaveinduced microfracture and to predict the effect of microwave power delivery and ore texture on microwave treatment of ores. Modelling rock using bonded assemblies of circular particles. Chandlerthe progressive fracture of lac du bonnet granite.
In the bpm, the intact rock is represented by a dense packing of rigid spheres or disks bonded together at their contacts. Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on youtube. Cempanel is produced by mixing fine wood particle, portland cement and mineralising agents. An alternative method consists in replacing a circular or spherical particle at its fracture threshold by several. Sep 05, 2006 the bonded particle model for rock potyondy and cundall, 2004 represents rock by a dense packing of nonuniformsized circular or spherical particles that are bonded together at their contact points and whose mechanical behavior is simulated by the distinctelement method using the two and threedimensional programs pfc2d and pfc3d. Understanding the effects of mineralogy, ore texture and. Cellulosic materials, including dimension lumber, plywood, particle board, wafer board, paper, fabric and similar materials, were treated with sodium silicate na2o. A numerical model for rock is proposed in which the rock is represented by a dense packing of nonuniformsized circular or spherical particles that are bonded together at their contact points and. The bondedparticle model for rock bpm, potyondy and cundall 1 is enhanced to include timedependent behavior. Omniroc fire resistant structural panels, cement bonded. However, since different loading rates were used, it is difficult to assess the numerical results of these studies if the effects of the loading rate are ignored. The discrete element method dem appears as one of the most attractive methods for understanding general geotechnical problems and specifically the behavior of rocks due to their unique advantages in dealing with fracturing. Cracking processes have been extensively studied in brittle rock and rock like materials. The bondedparticle model for rock referred to hereafter as the bpm directly mimics this system and thus exhibits a rich set of emergent behaviors that correspond very well with those of real rock.
Research on crack initiation mechanism and fracture criterion. Cundallb a university of toronto, department of civil engineering and lassonde institute, toronto, ont. Wood is a natural material for instance cement fiber panels, gypsum fiber board, sheet rock, particle board, or osb. North america global cement bonded particle board market by product type 6. Mechanical analysis and interpretation of excavation damage. Simulating stress corrosion with a bonded particle model. Discrete element simulation of coal cutting scientific. Murrell 1958 proposed the application of griffith theory to rock. The chips in the surface layer are thinner than those in the middle layer, so the surface of the particle board is denser and more compact than the middle. Based on over thirty years of research and practical application, naprotechnology natural procreative technology is a womens health science which has, as its main principle, the ability to work cooperatively with the womans menstrual and fertility cycle. Use of the distinctelement method allows dynamic stress waves to propagate through the.
During the manufacturing and curing process, the wood. Insights into the seismicallyinduced rockslope failures in. Sio2kg water and the surfaces of selected samples were further treated with silicon oxide sio or sio2 applied in a molecular to micron layer thickness by vapor deposition. However, once a tensile bond is broken the tensile strength of particle bonding is set to zero regardless of its contact condition i. A numerical model for rock that extends the formulation of the bondedparticle model bpm to include timedependent behavior by adding a damagerate law to the parallelbond formulation is described. The resultant model is commonly referred to as the bondedparticle model bpm for rock potyondy and cundall, 2004. Calibration and verification of two bondedparticle models. As a first step, an intact rock specimen without weak planes was modeled as an isotropic rock using the bonded particle model. Granulation and particlebonding mechanism of granulation all about granulation including reasons for granulation, bonding mechanisms between particles, mechanisms of granule formation and. Bonded particle modeling of thermally induced damage in rock.
Choosing a proper loading rate for bondedparticle model. Estimation of fill strength requirements using bonded. Bondedparticle model bpm is widely used to model geomaterials, in which calibration against the results from uniaxialtriaxial compressive tests, brazilian tensile tests and shear tests have been commonly conducted. Three rock slope geometries were built and evaluated in pfc. It has been shown that the amount of microcracks and also the cracks pattern in an ore sample after microwave treatment significantly depend on its mineralogy, microwave treatment condition power density and absorbent phase. Choosing a proper loading rate for bondedparticle model of. The technique uses the bonded particle model bpm for rock to represent intact material and the.
Due to the experimental limitations and the complexity of rock texture, details of the cracking processes could not always be observed and assessed comprehensively. A bondedparticle model for cemented sand sciencedirect. Factors affecting crack initiation in low porosity. Pdf bonded particle model for jointed rock mass researchgate.
Simulating stress corrosion with a bondedparticle model. North america global cement bonded particle board market by country 6. The serial number can be found on the bottom of the crank housing as shown see diagram below. It combines the strength of cement with the flexibility of wood. It has attracted numerous efforts to model the rock chipping and fragmentation process, especially using the explicit finite element method fem and bonded particle model bpm, in order to improve cutting efficiency. The bonded particle model for rock referred to hereafter as the bpm directly mimics this system and thus exhibits a rich set of emergent behaviors that correspond very well with those of real rock. Technologies for rapid production of mineralbonded wood. To contribute to this field of research, a numerical approach based on the particle element model was used in present study. Effect of particle shape on mechanical behaviors of rocks. A parallelbonded chemical corrosion model for discrete. Cracking and coalescence behavior in a rectangular rock like specimen containing two parallel stepped and coplanar preexisting open flaws under uniaxial compression load has been numerically studied by a parallel bondedparticle model, which is a type of bondedparticle model. The effects of void shape on the mechanical properties of rock. Modeling acoustic emissions in heterogeneous rocks during.
Wood composites manufactured with iorganic binders may contain 30 to 90. An important parameter of the model is the strength difference between tension and compression of the bond element. Computational simulations of microwave heating and thermal damage have been. We generalize our view of a bondedparticle model bpm to consist of a base. The bpm provides both a scientific tool to investigate the micromechanisms that combine to produce complex macroscopic behaviors and an. The analyses are done in two and threedimensions using the particle flow code pfc. As explained in panelguide section 2, cbpb that is used in construction must comply by law with the construction products regulation cpr by compliance with bs en 986.
Pdf jointed rock masses are formed of intact rock and joints. Simulating stress corrosion with a bonded particle model for rock. International journal of rock mechanics and mining sciences 41. It is light gray in color and is flat and smooth on both surfaces.
The fresh boards are kept in the maturing store and passed through the conditioning chamber to bring them to equilibrium moisture content. Pdf bondedparticle model with nonlinear elastic tensile. A bonded particle model simulation of shear strength and. In the future, the model could be adapted to other types of bonded materials like asphalt or rock. Deepdyve is the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. The numerical approach was based on grainbased model that utilized the voronoi tessellation scheme to represent low porosity. A parallel bonding model is proposed in this study to investigate the failure of basalt subjected to uniaxial compression. Versapanel is a class 0 cement bonded particle board comprising of wood particles and cement. Unlike loose particle materials sand and soil, rock particles are strongly bonded together. Apr 04, 2017 in this study, bonded particle models were used to simulate the intact rock behavior of westerly granite. A numerical study based on bondedparticle model approach. Granulation and particlebonding mechanism of granulation. The bondedparticle model for rock is such a particle model, and the.
Bondedparticle modelling of microwaveinduced damage in ore. Consequently, potyondy and cundall proposed a bondedparticle model for rock, where rock is represented by a dense packing of spherical particles that are bonded together. A flatjointed bondedparticle material for hard rock. Journal of rock mechanics and geotechnical engineering. Although compressive failure is wellmodeled in dem hazzard and young,2004, tensile. We generalize our view of a bondedparticle model bpm to consist of a base material that is a packed assembly of rigid grains joined by deformable and breakable cement at graingrain contacts to which largerscale joints can be added and whose mechanical behavior is simulated by the distinctelement method using the two and threedimensional discontinuum programs pfc2d and pfc3d. Acknowledgements much of the development of the bondedparticle model has been funded by atomic energy of canada limited and ontario power generation during the years 19952001 as part of its thermalmechanical stability study, with a goal of producing a mechanistically based numerical model that can predict excavationinduced rockmass. This bonded particle model bpm has been employed to investigate the behavior of crushable soils, rocks, fault gouge, and other materials 7,22,3241. The microstrength of sand mold is analyzed based on bondedparticle model bpm due to the. In a bpm, crack nucleation is simulated through breaking of internal bonds while fracture propagation is obtained by coalescence of multiple bond breakages. Zhang, xp, wong, lny 20 a crack initiation, propagation and coalescence in rocklike material containing two flaws. An experimental study of mechanical behavior of brittle rock.
Bondedparticle modeling of thermally induced damage in rock. In flatpressed particle board, the chips are mainly parallel to the surface. Model serial number identification each dynacraft bicycle has a serial number stamped into the frame. Bondedparticle model with nonlinear elastic tensile. Its really necessary to determine freezethaw resistance of concrete faster and correctly. The model number and production date are found on a. Bondedparticle modelling of microwaveinduced damage in. The paper presents a brief overview of the constitutive model and calibration of the discrete element model by simulation of the uniaxial test and brazilian tests and analyze the movement of picks. Consequently, potyondy and cundall proposed a bonded particle model for rock, where rock is represented by a dense packing of spherical particles that are bonded together. This property controls the influence of the confining pressure on peak strength. Cempanel is one of the most durable building boards. Simulation of resistance and deformability of rocks via. Mechanical cutting provides one of the most flexible and environmentally friendly excavation methods. Bondedparticle discrete element modeling of mechanical.
Effect of base sand on the properties of ester cured sodium silicate sand. Park jw, song jj 2009 numerical simulation of a direct shear test on a rock joint using a bondedparticle model. In this paper, numerical simulation using a bonded particle model was undertaken to provide a better understanding of the mechanism of microwaveinduced microfracture and to predict the effect of microwave power delivery and ore texture on microwave treatment of ores. It is suitable for a wide range of applications,giving a high level of performance in the presence of moisture and fire.
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