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https://hdl.handle.net/10784/29068

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Compressive Deformation Behaviour of Asphalt Mixtures
(Association of Asphalt Paving Technologist, 2006-08-01) Ossa, Edgar Alexander; Ossa, Edgar Alexander; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Dilation behaviour of asphalt mixtures
(Taylor and Francis Ltd., 2006-08-01) Ossa, Edgar Alexander; Ossa, Edgar Alexander; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Failure analysis of a civil aircraft landing gear
(PERGAMON-ELSEVIER SCIENCE LTD, 2006-10-01) Ossa, Edgar Alexander; Ossa, Edgar Alexander; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Spherical indentation behavior of asphalt mixtures
(ASCE-AMER SOC CIVIL ENGINEERS, 2007-01-01) Ossa, E.A.; Collop, A.C.; Ossa, E.A.; Collop, A.C.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
The spherical indentation response of a dense bitumen macadam asphalt mixture with two different volume fractions of bitumen binder is investigated both experimentally and via an analytical model. The model for the indentation of bitumen developed by Ossa et al. in 2005, was used to study the spherical indentation behavior of the mixtures with good agreement when compared to experimental results. An extensive experimental study of the monotonic and recovery spherical indentation behavior is reported for a range of temperatures. In line with the predictions of the model, the monotonic indentation response of the mixtures exhibits a power-law dependence on the indentation force. The model is also successful in capturing the indentation recovery behavior of the mixtures. A comparison of the material parameters obtained from uniaxial compression and indentation tests showed that indentation tests can be used in an easy and reliable way to obtain the fundamental asphalt parameters. Further, parameters found from indentation tests implicitly account for the confining conditions generated by the aggregate particles below the indenter. © 2007 ASCE.
Estudio comparativo de las propiedades mecánicas de fibras de vidrio y queratina
(2007-09-01) Ossa, Edgar Alexander; Montoya, Carolina; Ossa, Edgar Alexander; Montoya, Carolina; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Análisis de falla de la mordaza plana de una prensa hidráulica
(IMPRENTA UNIV ANTIOQUIA, 2008-01-01) Ossa, E.A.; Paniagua, M.A.; Ossa, E.A.; Paniagua, M.A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
This paper describes the analysis and investigation of the causes of the failure of an hydraulic press jaw face grip. Analysis of the fractured surfaces indicated the creation of cracks due to stress concentrators as a result of defective design. On the other hand, metallographic examination revealed the presence of aligned clusters of primary carbides that along with the stress concentrators induced the premature failure of the grip.
Características de adhesión entre fibras de queratina y poliéster insaturado
(IMPRENTA UNIV ANTIOQUIA, 2008-01-01) Paniagua, M.; Ossa, A.; Ruiz, G.; Paniagua, M.; Ossa, A.; Ruiz, G.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
This work presents the methods and results employed to find the adhesion characteristics between keratin fibers and unsaturated polyester as matrix material. The fibers were conditioned prior to testing using four different methods in order to establish the effect of these treatments on the adhesion to the matrix by means of i) monofilament pull-out testing, as direct method; and ii) Lamina tensile tests as indirect method to analyze the adhesion in the fracture zone with the help of electron microscopy (SEM).
Failure analysis of a hydraulic press clamp
(IMPRENTA UNIV ANTIOQUIA, 2008-06-01) Ossa, Edgar Alexander; Paniagua, Marco Aurelio; Ossa, Edgar Alexander; Paniagua, Marco Aurelio; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
This paper describes the analysis and investigation of the causes of the failure of an hydraulic press jaw face grip. Analysis of the fractured surfaces indicated the creation of cracks due to stress concentrators as a result of defective design. On the other hand, metallographic examination revealed the presence of aligned clusters of primary carbides that along with the stress concentrators induced the premature failure of the grip.
Adhesion characteristics between keratin fibers and unsaturated polyester
(IMPRENTA UNIV ANTIOQUIA, 2008-12-01) Paniagua, Marco; Ossa, Alexander; Ruiz, Gladys; Paniagua, Marco; Ossa, Alexander; Ruiz, Gladys; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
This work presents the methods and results employed to find the adhesion characteristics between keratin fibers and unsaturated polyester as matrix material. The fibers were conditioned prior to testing using four different methods in order to establish the effect of these treatments on the adhesion to the matrix by means of i) monofilament pull-out testing, as direct method; and ii) Lamina tensile tests as indirect method to analyze the adhesion in the fracture zone with the help of electron microscopy (SEM).
Modelación micromecánica de polímeros reforzados con partículas
(IMPRENTA UNIV ANTIOQUIA, 2010-01-01) Henao, E.A.O.; Henao, E.A.O.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
This work describes an easy to use constitutive model able to predict the mechanical behavior of polymer matrix particulate composites at temperatures above the glass transition temperature Tg. This model was based on both phenomenological and micromechanical theories. With the model proposed it is possible to obtain the properties of the material (macro) using the characteristics of its components (micro). This model exhibits a reasonable agreement with experiments under various volume fractions of particles.
Triaxial deformation behavior of bituminous mixes
(ASCE-AMER SOC CIVIL ENGINEERS, 2010-02-01) Ossa, E. A.; Deshpande, V. S.; Cebon, D.; Ossa, E. A.; Deshpande, V. S.; Cebon, D.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
The triaxial compressive response of bituminous mixes with volume fractions of aggregate in the range 52 to 85% was investigated over a wide range stresses and strain rates. The types of loadings considered include triaxial monotonic constant stress and constant applied strain rate, as well as creep recovery, continuous cyclic, and stress pulse train loadings. The mixes with a "fully dense" aggregate skeleton were found to dilate under all loading conditions and the creep response of the mixes was dependent on both the deviatoric and hydrostatic stresses. By contrast, recovery was found to occur under zero applied deviatoric stresses with the recovery rate only dependent on the "recoverable strain" and independent of any superimposed hydrostatic stress. Continuous and pulse loading cyclic stress-controlled tests showed that the response of the mixes was governed by the mean applied deviatoric stress in the continuous cyclic tests while strain recovery was important in the pulse loading tests. A phenomenological constitutive model was proposed to fit the measured triaxial response of the bituminous mixes and shown to capture the measurements over all the triaxial stress states and loading time histories investigated here. Furthermore, the model was extended to capture the temperature dependence of the mixtures which is governed by the temperature dependence of the bitumen binder. © 2010 ASCE.
Micromechanical modeling of particle reinforced polymers
(IMPRENTA UNIV ANTIOQUIA, 2010-08-01) Ossa Henao, Edgar Alexander; Ossa Henao, Edgar Alexander; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
This work describes an easy to use constitutive model able to predict the mechanical behavior of polymer matrix particulate composites at temperatures above the glass transition temperature Tg. This model was basedon both phenomenological and micromechanical theories. With the model proposed it is possible to obtain the properties of the material (macro) using the characteristics of its components (micro). This model exhibits a reasonable agreement with experiments under various volume fractions of particles.
Modeling and analysis of susceptibility to permanent deformation in asphalt mixtures
(Pontificia Universidad Católica de Chile, 2011-01-01) Julián Vidal V.; Ossa A.; Julián Vidal V.; Ossa A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Perm. Deformation of Asphaltic Mixtures in the Metropol. Area of Valle de Aburra - Antioquia, Which Are Built under IVIAS' Specifications and Valle de Aburra, Were Studied by Employing A Constitutive Model Proposed Previously. This Model Had Proved to Be Effective in Predicting Deformations of Asphaltic Mixtures in the U. Kingdom under Different Kinds of Loads; under Uniaxial and Triaxial Conditions and Temperatures at Intervals between 0C and 40C. for the Specific Case of Valle de Aburra, Temperatures Ranged between 20C and 50C and the Model Was Implemented in Order to Predict Susceptibility to Perm. Deformation. by Means of An Exp. Stud. on Mixtures, It Was Found That Their Behav. under Steady State Condition Followed the Model Modified by Cross2, Thus Mixtures Showed A Visco-Lin. and Non-Lin. Behav. at Low and High Stress Levels, Respectively. It Was Observed That under Loading and Unloading Conditions, There Is A Temp. Dependence on the Mat. Behav., Which Was Properly Predicted by Arrhenius3 under the Studied Temperatures Interval. When Modeling Mixtures Behav., It Was Found That That Their Strain Susceptibility Varied Widely Depending on the Constituent Mat., Especially on the Aggregate, in Spite of the Fact That the Mixtures Are Similar.
Failure analysis of a car suspension system ball joint
(PERGAMON-ELSEVIER SCIENCE LTD, 2011-07-01) Ossa, E. A.; Palacio, C. C.; Paniagua, M. A.; Ossa, E. A.; Palacio, C. C.; Paniagua, M. A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Three-dimensional evaluation of mandibular bone regenerated by bone transport distraction osteogenesis
(SPRINGER, 2011-07-01) Kontogiorgos, E.; Elsalanty, M.E.; Zapata, U.; Zakhary, I.; Nagy, W.W.; Dechow, P.C.; Opperman, L.A.; Kontogiorgos, E.; Elsalanty, M.E.; Zapata, U.; Zakhary, I.; Nagy, W.W.; Dechow, P.C.; Opperman, L.A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
The purpose of this study was to evaluate the structure and material properties of native mandibular bone and those of early regenerate bone, produced by bone transport distraction osteogenesis. Ten adult foxhounds were divided into two groups of five animals each. In all animals, a 3- to 4-cm defect was created on one side of the mandible. A bone transport reconstruction plate, consisting of a reconstruction plate with an attached intraoral transport unit, was utilized to stabilize the mandible and regenerate bone at a rate of 1 mm/day. After the distraction period was finished, the animals were killed at 6 and 12 weeks of consolidation. Micro-computed tomography was used to assess the morphometric and structural indices of regenerate bone and matching bone from the unoperated contralateral side. Significant new bone was formed within the defect in the 6- and 12-week groups. Significant differences (P = 0.05) between mandibular regenerated and native bone were found in regard to bone volume fraction, mineral density, bone surface ratio, trabecular thickness, trabecular separation, and connectivity density, which increased from 12 to 18 weeks of consolidation. We showed that regenerated bone is still mineralizing and that native bone appears denser because of a thick outer layer of cortical bone that is not yet formed in the regenerate. However, the regenerate showed a significantly higher number of thicker trabeculae. © 2011 Springer Science+Business Media, LLC.
Modelación y análisis de susceptibilidad a la deformación permanente de mezclas asfálticas
(Pontificia Universidad Católica de Chile, 2011-08-01) Vidal J.; Alexander Ossa, E.; Vidal J.; Alexander Ossa, E.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
La deformación permanente de mezclas asfálticas del Área Metropolitana del Valle de Aburra ? Antioquia, las cuales se fabrican en nuestro medio bajo las especificaciones INVIAS (Instituto Nacional de Vías) y del Valle de Aburrá
Architecture and microstructure of cortical bone in reconstructed canine mandibles after bone transport distraction osteogenesis
(SPRINGER, 2011-11-01) Zapata, Uriel; Halvachs, Emily K.; Dechow, Paul C.; Elsalanty, Mohammed E.; Opperman, Lynne A.; Zapata, Uriel; Halvachs, Emily K.; Dechow, Paul C.; Elsalanty, Mohammed E.; Opperman, Lynne A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Reconstruction of the canine mandible using bone transport distraction osteogenesis has been shown to be a suitable method for correcting segmental bone defects produced by cancer, gunshots, and trauma. Although the mechanical quality of the new regenerate cortical bone seems to be related to the mineralization process, several questions regarding the microstructural patterns of the new bony tissue remain unanswered. The purpose of this study was to quantify any microstructural differences that may exist between the regenerate and control cortical bone. Five adult American foxhound dogs underwent unilateral bone transport distraction of the mandible to repair bone defects of 30-35 mm. Animals were killed 12 weeks after the beginning of the consolidation period. Fourteen cylindrical cortical samples were extracted from the superior, medial, and inferior aspects of the lingual and buccal plates of the reconstructed aspect of the mandible, and 21 specimens were collected similarly from the contralateral aspect of the mandible. Specimens were evaluated using histomorphometric and micro-computed tomographic techniques to compare their microstructure. Except for differences in haversian canal area, histomorphometric analyses suggested no statistical differences in microstructure between regenerate and control cortical bone. Morphological evaluation suggested a consistent level of anisotropy, possibly related to the distraction vector. After 12 weeks' consolidation, bone created during bone transport distraction osteogenesis was comparable to native bone in microstructure, architecture, and mechanical properties. It is proposed that, after enough time, the properties of the regenerate bone will be identical to that of native bone. © Springer Science+Business Media, LLC 2010.
Bone regeneration and docking site healing after bone transport distraction osteogenesis in the canine mandible
(W.B. Saunders Ltd, 2012-01-01) Nagashima, L.K.; Rondon-Newby, M.; Zakhary, I.E.; Nagy, W.W.; Zapata, U.; Dechow, P.C.; Opperman, L.A.; Elsalanty, M.E.; Nagashima, L.K.; Rondon-Newby, M.; Zakhary, I.E.; Nagy, W.W.; Zapata, U.; Dechow, P.C.; Opperman, L.A.; Elsalanty, M.E.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Purpose: Bone transport distraction osteogenesis provides a promising alternative to traditional grafting techniques. However, existing bone transport distraction osteogenesis devices have many limitations. The purpose of this research was to test a new device, the mandibular bone transport reconstruction plate, in an animal model with comparable mandible size to humans and to histologically and mechanically examine the regenerate bone. Materials and Methods: Eleven adult foxhounds were divided into an unreconstructed control group of 5 animals and an experimental group of 6 animals. In each animal, a 34-mm segmental defect was created in the mandible. The defect was reconstructed with a bone transport reconstruction plate. Histologic and biomechanical characteristics of the regenerate and unrepaired defect were analyzed and compared with bone on the contralateral side of the mandible after 4 weeks of consolidation. Results: The reconstructed defect was bridged with new bone, with little bone in the control defect. Regenerate density and microhardness were 22.3% and 42.6%, respectively, lower than the contralateral normal bone. Likewise, the anisotropy of the experimental group was statistically lower than in the contralateral bone. Half the experimental animals showed nonunion at the docking site. Conclusion: The device was very stable and easy to install and activate. After 1 month of consolidation, the defect was bridged with new bone, with evidence of active bone formation. Regenerate bone was less mature than the control bone. Studies are underway to identify when the regenerate properties compare with normal bone and to identify methods to augment bone union at the docking site. © 2012 American Association of Oral and Maxillofacial Surgeons.
The Role of the Sutures in Biomechanical Dynamic Simulation of a Macaque Cranial Finite Element Model: Implications for the Evolution of Craniofacial Form
(Hoboken, 2012-02-01) Qian Wang; Wood, Sarah A; Grosse, Ian R; Ross, Callum F; Zapata U; Byron, Craig D.; Wright, Barth W.; Strait, David S.; Qian Wang; Wood, Sarah A; Grosse, Ian R; Ross, Callum F; Zapata U; Byron, Craig D.; Wright, Barth W.; Strait, David S.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
The global biomechanical impact of cranial sutures on the face and cranium during dynamic conditions is not well understood. It is hypothesized that sutures act as energy absorbers protecting skulls subjected to dynamic loads.
Criterios sismológicos para seleccionar acelerogramas reales de la Red Nacional de Acelerógrafos de Colombia para su uso en análisis dinámicos
(Escuela de Ingeniería de Antioquia, 2012-07-01) Acevedo A.B.; Acevedo A.B.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Utilizar acelerogramas reales para la realización de análisis dinámicos es deseable ya que contienen información real sobre la naturaleza del movimiento fuerte e indican las características variadas que diferentes sismos en lugares diversos pueden produci

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