Steven Benzley | Brigham Young University (original) (raw)
Papers by Steven Benzley
Springer eBooks, Jan 18, 2006
This paper presents an adaptivea pproacht o sweeping one-to-onea nd many-to-one geometry.The auto... more This paper presents an adaptivea pproacht o sweeping one-to-onea nd many-to-one geometry.The automatic decomposition of many-to-one geometry into one-to-one "blocks" andt he selection of an appropriate node projection scheme are vital steps in the efficientg eneration of high-qualitys wept meshes. This paper identifies two node projection schemes whicha re used in tandem to robustly sweep each block of ao ne-to-one geometry.M ethods are also presented for the characterization of one-to-one geometry and the automatic assignmento ft he most appropriate node projection scheme. These capabilities allow the sweeper to adapt to the requirements of the sweep block being processed. The identification of the two node projection schemes wasm ade after an extensive analysiso fe xisting schemes wasc ompleted. One of the node projection schemes implemented in thisw ork, BoundaryError, was selected from traditional node placementa lgorithms. Thes econd node projection scheme, SmartAffine, is an extension of simplea ffine transformations and is capable of efficiently sweeping geometry with source and/or target curvature whilea pproximating the speed of as imple transform. Theset wo schemes, when used in this adaptives etting, optimize mesh quality and the speed that swept meshes can be generated while minimizing required user interaction.
American Society of Mechanical Engineers eBooks, 1975
![Research paper thumbnail of PHYSICAL AND NUMERICAL SIMULATIONS OF SUBSIDENCE IN FRACTURED SHALE STRATA [abstract]](https://attachments.academia-assets.com/119939474/thumbnails/1.jpg)
](
The US Strategic Petroleum Reserve program for crude oil stockpiling utilizes some existing solut... more The US Strategic Petroleum Reserve program for crude oil stockpiling utilizes some existing solution mined caverns in Gulf Coast salt domes. Geomechanical analyses are impotant tools used to assess the structural stability of these caverns. This report addresses the ineractions between adjacent caverns which result from maintaining different pressures in the caverns. Finite element models of two adjacent caverns are analyzed for four different cavern spacings. The brine pressure is simulated in one cavern while the pressure in the adjacent cavern ranges from that of the oil head to atmospheric conditions. Stress distributions and deformed profiles of the caverns are plotted for the conditions simulated. Since the tensile strength of salt is low (typically 100 to 300 psi), regions in which tensile stresses occur are considered to have a significant probability of slabbing. A preliminary recommendation is made to maintain similar pressures to adjacent caverns in which the pillar thickness/cavern diameter ratio of the web between caverns is less than 0.5 unless cavern specific assessments indicate that the potential for pillar slabbing is minimal.
International Journal for Numerical and Analytical Methods in Geomechanics, Apr 1, 1982
A continuum finite element formulation that models the failure of a rock mass, the collapse of th... more A continuum finite element formulation that models the failure of a rock mass, the collapse of this rubble into a void space and the associated bulking of the rubble is presented. This formulation is incorporated into a finite element computer program that treats the large deformation non-linear motion of axisymmetric and two-dimensional continua. A dynamic relaxation procedure is used for the solution algorithm. Example calculations are given that demonstrate the formulation.
EPAD is a finite-element program for the static elastoplastic stress analysis of arbitrary bodies... more EPAD is a finite-element program for the static elastoplastic stress analysis of arbitrary bodies of revolution subjected to either symmetrical or unsymmetrical loadings. EPAD1 and EPAD2 incorporate the original version of EPAD (AFWL-TR-69-146) with an automatic mesh generation program and an output plotting package. (LMT)
Brigham Young University, and the College of Engineering and Technology in particular, have imple... more Brigham Young University, and the College of Engineering and Technology in particular, have implemented an open, shared resource computing environment allowing the interconnection of personal computers, workstations, mainframes and supercomputers across the campus and to the outside world. This strategy supports the classroom, research and communication needs of students and faculty. Facilities acquisition, system configuration, management and system modernization issues are all addressed in this paper.
Science and Engineering Ethics, 2000
CHILES 2 is a finite element computer program that calcu lates the strength o£ singularities in l... more CHILES 2 is a finite element computer program that calcu lates the strength o£ singularities in linear elastic bodies. A generalized quadrilateral finite element that includes a singular point at a corner node is incorporated in the code. The displacement formulation is used and interelement compat ibility is maintained so that monotone convergence is preserved. Plane stress, plane strain and axisymmetric conditions are treated. Isotropic and orthotropic crack tip singularity prob lems are solved by this version of the code but any type of singularity may be properly modeled by modifying selected sub routines in the program.
The Shock and Vibration Digest, Feb 1, 1976
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, Oct 1, 1981
This paper describes surface subsidence moni-tc~ing. The lomgwall mines subsidence profiles, amgl... more This paper describes surface subsidence moni-tc~ing. The lomgwall mines subsidence profiles, amgle of d.raw, subsidemce factor anl subsidence development c~ve are discussed with reference to surface structures.
Modeling the failure and settlement of strata above mine openings requires a knowledge of several... more Modeling the failure and settlement of strata above mine openings requires a knowledge of several different geomechanical processes such as the failure of the rock mass above the mine opening, the fall of this mass into the opening, the associated bulking of the rock rubble, and the recompaction of the rubble under subsequent loading. These processes have been studied in this paper by using centrifuge experiments and numerical models to characterize the strata movement above a mine drift that is located below many relatively thin layers of strata. The centrifuge simulations show progressive failure of the strata, the formation of a corbeled arch over the mine drift and ultimately the formation of a subsidence trough. The quantitative data from these experiments are analyzed using finite element numerical techniques.
Finite element stress analysis procedures are employed to study several structural characteristic... more Finite element stress analysis procedures are employed to study several structural characteristics of the Weeks Island Salt Mine. The existing mine is being converted to a reservoir for oil storage and new salt mining beneath the reservoir is planned. The present analysis addresses the concern of appropriate separation between the oil repository and the proposed mining. Creep calculations for a
Springer eBooks, Jan 18, 2006
This paper presents an adaptivea pproacht o sweeping one-to-onea nd many-to-one geometry.The auto... more This paper presents an adaptivea pproacht o sweeping one-to-onea nd many-to-one geometry.The automatic decomposition of many-to-one geometry into one-to-one "blocks" andt he selection of an appropriate node projection scheme are vital steps in the efficientg eneration of high-qualitys wept meshes. This paper identifies two node projection schemes whicha re used in tandem to robustly sweep each block of ao ne-to-one geometry.M ethods are also presented for the characterization of one-to-one geometry and the automatic assignmento ft he most appropriate node projection scheme. These capabilities allow the sweeper to adapt to the requirements of the sweep block being processed. The identification of the two node projection schemes wasm ade after an extensive analysiso fe xisting schemes wasc ompleted. One of the node projection schemes implemented in thisw ork, BoundaryError, was selected from traditional node placementa lgorithms. Thes econd node projection scheme, SmartAffine, is an extension of simplea ffine transformations and is capable of efficiently sweeping geometry with source and/or target curvature whilea pproximating the speed of as imple transform. Theset wo schemes, when used in this adaptives etting, optimize mesh quality and the speed that swept meshes can be generated while minimizing required user interaction.
American Society of Mechanical Engineers eBooks, 1975
The US Strategic Petroleum Reserve program for crude oil stockpiling utilizes some existing solut... more The US Strategic Petroleum Reserve program for crude oil stockpiling utilizes some existing solution mined caverns in Gulf Coast salt domes. Geomechanical analyses are impotant tools used to assess the structural stability of these caverns. This report addresses the ineractions between adjacent caverns which result from maintaining different pressures in the caverns. Finite element models of two adjacent caverns are analyzed for four different cavern spacings. The brine pressure is simulated in one cavern while the pressure in the adjacent cavern ranges from that of the oil head to atmospheric conditions. Stress distributions and deformed profiles of the caverns are plotted for the conditions simulated. Since the tensile strength of salt is low (typically 100 to 300 psi), regions in which tensile stresses occur are considered to have a significant probability of slabbing. A preliminary recommendation is made to maintain similar pressures to adjacent caverns in which the pillar thickness/cavern diameter ratio of the web between caverns is less than 0.5 unless cavern specific assessments indicate that the potential for pillar slabbing is minimal.
International Journal for Numerical and Analytical Methods in Geomechanics, Apr 1, 1982
A continuum finite element formulation that models the failure of a rock mass, the collapse of th... more A continuum finite element formulation that models the failure of a rock mass, the collapse of this rubble into a void space and the associated bulking of the rubble is presented. This formulation is incorporated into a finite element computer program that treats the large deformation non-linear motion of axisymmetric and two-dimensional continua. A dynamic relaxation procedure is used for the solution algorithm. Example calculations are given that demonstrate the formulation.
EPAD is a finite-element program for the static elastoplastic stress analysis of arbitrary bodies... more EPAD is a finite-element program for the static elastoplastic stress analysis of arbitrary bodies of revolution subjected to either symmetrical or unsymmetrical loadings. EPAD1 and EPAD2 incorporate the original version of EPAD (AFWL-TR-69-146) with an automatic mesh generation program and an output plotting package. (LMT)
Brigham Young University, and the College of Engineering and Technology in particular, have imple... more Brigham Young University, and the College of Engineering and Technology in particular, have implemented an open, shared resource computing environment allowing the interconnection of personal computers, workstations, mainframes and supercomputers across the campus and to the outside world. This strategy supports the classroom, research and communication needs of students and faculty. Facilities acquisition, system configuration, management and system modernization issues are all addressed in this paper.
Science and Engineering Ethics, 2000
CHILES 2 is a finite element computer program that calcu lates the strength o£ singularities in l... more CHILES 2 is a finite element computer program that calcu lates the strength o£ singularities in linear elastic bodies. A generalized quadrilateral finite element that includes a singular point at a corner node is incorporated in the code. The displacement formulation is used and interelement compat ibility is maintained so that monotone convergence is preserved. Plane stress, plane strain and axisymmetric conditions are treated. Isotropic and orthotropic crack tip singularity prob lems are solved by this version of the code but any type of singularity may be properly modeled by modifying selected sub routines in the program.
The Shock and Vibration Digest, Feb 1, 1976
International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts, Oct 1, 1981
This paper describes surface subsidence moni-tc~ing. The lomgwall mines subsidence profiles, amgl... more This paper describes surface subsidence moni-tc~ing. The lomgwall mines subsidence profiles, amgle of d.raw, subsidemce factor anl subsidence development c~ve are discussed with reference to surface structures.
Modeling the failure and settlement of strata above mine openings requires a knowledge of several... more Modeling the failure and settlement of strata above mine openings requires a knowledge of several different geomechanical processes such as the failure of the rock mass above the mine opening, the fall of this mass into the opening, the associated bulking of the rock rubble, and the recompaction of the rubble under subsequent loading. These processes have been studied in this paper by using centrifuge experiments and numerical models to characterize the strata movement above a mine drift that is located below many relatively thin layers of strata. The centrifuge simulations show progressive failure of the strata, the formation of a corbeled arch over the mine drift and ultimately the formation of a subsidence trough. The quantitative data from these experiments are analyzed using finite element numerical techniques.
Finite element stress analysis procedures are employed to study several structural characteristic... more Finite element stress analysis procedures are employed to study several structural characteristics of the Weeks Island Salt Mine. The existing mine is being converted to a reservoir for oil storage and new salt mining beneath the reservoir is planned. The present analysis addresses the concern of appropriate separation between the oil repository and the proposed mining. Creep calculations for a