Pub Date : 2001-11-11DOI: 10.1115/imece2001/pvp-25201
Y. W. Kwon, C. Liu
Hydrostatic pressure affects the damage growth in a particulate composite. As a result, an analytical model was presented to represent the damage growth in a particulate composite under various hydrostatic pressures. The model was based on a multi-level approach with damage description at the micro-level. A damage theory was presented to describe the material behavior under hydrostatic pressure. The effect of hydrostatic pressure was introduced to the damage theory through the damage function that was assumed to be a function of both deviatoric and volumetric strain energy densities. The predicted stress-strain curves with hydrostatic pressure compared well with the experimental data. Furthermore, the initial crack size at a notch tip was studied with and without hydrostatic pressure. The initial crack size determined from the computer modeling and simulation agreed well with the measured data with or without hydrostatic pressure.
{"title":"Effect of Hydrostatic Pressure on Damage in Particulate Composites","authors":"Y. W. Kwon, C. Liu","doi":"10.1115/imece2001/pvp-25201","DOIUrl":"https://doi.org/10.1115/imece2001/pvp-25201","url":null,"abstract":"\u0000 Hydrostatic pressure affects the damage growth in a particulate composite. As a result, an analytical model was presented to represent the damage growth in a particulate composite under various hydrostatic pressures. The model was based on a multi-level approach with damage description at the micro-level. A damage theory was presented to describe the material behavior under hydrostatic pressure. The effect of hydrostatic pressure was introduced to the damage theory through the damage function that was assumed to be a function of both deviatoric and volumetric strain energy densities. The predicted stress-strain curves with hydrostatic pressure compared well with the experimental data. Furthermore, the initial crack size at a notch tip was studied with and without hydrostatic pressure. The initial crack size determined from the computer modeling and simulation agreed well with the measured data with or without hydrostatic pressure.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125310081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/pvp-25205
O. Vinogradov
The nonlinear damping model introduced by Simon[1] combined with the Hertz model of contact elastic forces is applied to a two- and a multi-ball chain-type system (Newton’s Cradle). The numerical investigation is focused on inter-dependence between the numerical efficiency and accuracy for two- and a multi-ball system. An error control damping is introduced, which allows increased computational efficiency and at the same time error reduction.
{"title":"On a Model of a Ball in Cluster Impact Problems in Granular Mechanics","authors":"O. Vinogradov","doi":"10.1115/imece2001/pvp-25205","DOIUrl":"https://doi.org/10.1115/imece2001/pvp-25205","url":null,"abstract":"\u0000 The nonlinear damping model introduced by Simon[1] combined with the Hertz model of contact elastic forces is applied to a two- and a multi-ball chain-type system (Newton’s Cradle). The numerical investigation is focused on inter-dependence between the numerical efficiency and accuracy for two- and a multi-ball system. An error control damping is introduced, which allows increased computational efficiency and at the same time error reduction.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125485984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/pvp-25213
A. Saigal, V. S. Joshi
Aluminum/Polytetrafluoroethylene mixtures are currently being studied as reactive material compositions, with focus on shock or impact ignition. In addition, there is an emphasis on increasing the strength of these composites to survive high strain-rate deformation. In this research, an analytical model, based on Eshelby’s approach, and a three-dimensional elastoplastic finite element model were developed along with experimental measurements to investigate the effect of the shape and size of aluminum: spherical particles, whiskers, and fibers, on the strength and stiffness of Aluminum/Polytetrafluoroethylene composites. It was found that the existing surface and size characteristics of aluminum particles (e.g. texturing) play an important role on the mechanical behavior of these composites.
{"title":"Strength and Stiffness of Aluminum/PTFE Reactive Composites","authors":"A. Saigal, V. S. Joshi","doi":"10.1115/imece2001/pvp-25213","DOIUrl":"https://doi.org/10.1115/imece2001/pvp-25213","url":null,"abstract":"\u0000 Aluminum/Polytetrafluoroethylene mixtures are currently being studied as reactive material compositions, with focus on shock or impact ignition. In addition, there is an emphasis on increasing the strength of these composites to survive high strain-rate deformation. In this research, an analytical model, based on Eshelby’s approach, and a three-dimensional elastoplastic finite element model were developed along with experimental measurements to investigate the effect of the shape and size of aluminum: spherical particles, whiskers, and fibers, on the strength and stiffness of Aluminum/Polytetrafluoroethylene composites. It was found that the existing surface and size characteristics of aluminum particles (e.g. texturing) play an important role on the mechanical behavior of these composites.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133747312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/pvp-25218
R. Verderber
This paper describes automatic repetitive remapping applied to the solution of indirect extrusion. The application for indirect extrusion is microforging. The remapping algorithm and automatic remapping are critical in the Lagrangian solution of indirect extrusion. The FEA prediction agrees with a closed form solution of the die extrusion force.
{"title":"Automatic Repetitive Remapping Applied to the Solution of Indirect Extrusion","authors":"R. Verderber","doi":"10.1115/imece2001/pvp-25218","DOIUrl":"https://doi.org/10.1115/imece2001/pvp-25218","url":null,"abstract":"\u0000 This paper describes automatic repetitive remapping applied to the solution of indirect extrusion. The application for indirect extrusion is microforging. The remapping algorithm and automatic remapping are critical in the Lagrangian solution of indirect extrusion. The FEA prediction agrees with a closed form solution of the die extrusion force.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134548185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/pvp-25204
N. K. Chandiramani, L. I. Librescu, C. Shete
The free vibration behavior of a rotating blade modeled as a laminated composite hollow (single celled) box beam is studied. The geometrically nonlinear structural model developed herein incorporates a number of non-classical effects such as anisotropy, heterogeneity, transverse shear flexibility, and warping inhibition. The centrifugal and Coriolis force field effects are also included. The main focus here being the refinement of the existing model, the traction-free boundary conditions are satisfied here in contrast to the existing model. The resulting linearized equations and numerical results based on them are presented. Results obtained for the present higher-order shearable model are compared with those of the existing first-order shearable and the non-shearable models. Tailoring studies using the present model reveal an enhancement of eigenfrequency characteristics.
{"title":"Free-Vibration of Rotating Composite Beams Incorporating Higher-Order Transverse Shear Effects","authors":"N. K. Chandiramani, L. I. Librescu, C. Shete","doi":"10.1115/imece2001/pvp-25204","DOIUrl":"https://doi.org/10.1115/imece2001/pvp-25204","url":null,"abstract":"\u0000 The free vibration behavior of a rotating blade modeled as a laminated composite hollow (single celled) box beam is studied. The geometrically nonlinear structural model developed herein incorporates a number of non-classical effects such as anisotropy, heterogeneity, transverse shear flexibility, and warping inhibition. The centrifugal and Coriolis force field effects are also included. The main focus here being the refinement of the existing model, the traction-free boundary conditions are satisfied here in contrast to the existing model. The resulting linearized equations and numerical results based on them are presented. Results obtained for the present higher-order shearable model are compared with those of the existing first-order shearable and the non-shearable models. Tailoring studies using the present model reveal an enhancement of eigenfrequency characteristics.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"123 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116433325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/pvp-25217
S. Launis, E. Keskinen
Winding is a paper finishing process, in which the full paper web is longitudinally cut and wound in narrower paper rolls to fit later to printing machines. The quality of the paper roll is measured in terms of uniform roundness and axially symmetric internal stress and stiffness distribution. Unfortunately dynamic effects disturb winding process so that out-of-roundness shape error profiles may accumulate to the rolls. The reason for this phenomenon is mechanical oscillation, in which the set of rolls and the three winding drums are in relative motion in normal direction of their rolling contact plane. The time evolution of this process is extremely complicated since the roll size as well as contact conditions and running frequencies are changing during the complete process. To avoid unwanted resonance crossings the system eigenstates have to be as first step analyzed and compared with the roll speed harmonics at each roll diameter. This analysis is carried out using linearized spring-mass model, whose parameters are updated according to the roll growth. The spring elements represent the local stiffnesses of roll-drum contacts in both normal and tangential directions, the effect of latter ones being actually a novel element introduced in this analysis.
{"title":"Eigenvalue Analysis of Oscillatory Variable State Paper Winder","authors":"S. Launis, E. Keskinen","doi":"10.1115/imece2001/pvp-25217","DOIUrl":"https://doi.org/10.1115/imece2001/pvp-25217","url":null,"abstract":"\u0000 Winding is a paper finishing process, in which the full paper web is longitudinally cut and wound in narrower paper rolls to fit later to printing machines. The quality of the paper roll is measured in terms of uniform roundness and axially symmetric internal stress and stiffness distribution. Unfortunately dynamic effects disturb winding process so that out-of-roundness shape error profiles may accumulate to the rolls. The reason for this phenomenon is mechanical oscillation, in which the set of rolls and the three winding drums are in relative motion in normal direction of their rolling contact plane. The time evolution of this process is extremely complicated since the roll size as well as contact conditions and running frequencies are changing during the complete process. To avoid unwanted resonance crossings the system eigenstates have to be as first step analyzed and compared with the roll speed harmonics at each roll diameter. This analysis is carried out using linearized spring-mass model, whose parameters are updated according to the roll growth. The spring elements represent the local stiffnesses of roll-drum contacts in both normal and tangential directions, the effect of latter ones being actually a novel element introduced in this analysis.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124441938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/pvp-25207
Kevin A. Kerr, J. Hashemi, Jordan Post, K. Ngo, E. Dabezies
The reverse obliquity hip fracture is an unstable intertrochanteric fracture. The existing treatments of the reverse obliquity hip fracture have a high failure rate leading to re-operation. The objective of this study was to design an experimental setup to systematically evaluate and quantitatively document the effectiveness of various fixation devices used to treat the reverse obliquity hip fracture. The fixation devices tested and analyzed were 1) the 135 Degree Dynamic Hip Screw with a Trochanteric Stabilizing Plate (DHS/TSP)®, 2) the 95 Degree Condylar Hip Screw (CHS)®, and 3) the Recon Nail®. These devices were implanted in composite sawbone specimens with material properties close to that of human bone. All devices were tested under identical cyclic loading conditions. Based on a quantitative stability analysis, the 95 Degree CHS® showed the most promise for treatment of non-comminuted reverse obliquity hip fractures. The Recon nail® caused the bone to fracture at areas of high stress concentration and the 135 Degree DHS/TSP® was associated with high values of stress shielding. In this paper, the experimental set-up will be presented, the generated data will be discussed, and the performance of each fixation device will be analyzed.
{"title":"Comparative Analysis of Implant Effectiveness in Maintaining the Stability of the Reverse Obliquity Hip Fracture","authors":"Kevin A. Kerr, J. Hashemi, Jordan Post, K. Ngo, E. Dabezies","doi":"10.1115/imece2001/pvp-25207","DOIUrl":"https://doi.org/10.1115/imece2001/pvp-25207","url":null,"abstract":"\u0000 The reverse obliquity hip fracture is an unstable intertrochanteric fracture. The existing treatments of the reverse obliquity hip fracture have a high failure rate leading to re-operation. The objective of this study was to design an experimental setup to systematically evaluate and quantitatively document the effectiveness of various fixation devices used to treat the reverse obliquity hip fracture.\u0000 The fixation devices tested and analyzed were 1) the 135 Degree Dynamic Hip Screw with a Trochanteric Stabilizing Plate (DHS/TSP)®, 2) the 95 Degree Condylar Hip Screw (CHS)®, and 3) the Recon Nail®. These devices were implanted in composite sawbone specimens with material properties close to that of human bone. All devices were tested under identical cyclic loading conditions. Based on a quantitative stability analysis, the 95 Degree CHS® showed the most promise for treatment of non-comminuted reverse obliquity hip fractures. The Recon nail® caused the bone to fracture at areas of high stress concentration and the 135 Degree DHS/TSP® was associated with high values of stress shielding. In this paper, the experimental set-up will be presented, the generated data will be discussed, and the performance of each fixation device will be analyzed.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128756805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/pvp-25203
R. Cammino, M. Gosz, S. Mostovoy
We explore the use of constant K fracture specimens for experimental determination of fatigue properties of aluminum alloys. The shape of the contoured portions of the fracture specimens (required to keep the mode I stress intensity factor constant during crack propagation under constant cyclic loading) was obtained by a combined finite element-least squares minimization procedure. After conducting the experiments, the crack growth rate versus ΔK data was observed to exhibit significantly less scatter than fatigue data for the same material taken from the literature. In addition, the experimental procedure is much simpler to carry out than traditional closed-loop computer controlled procedures.
{"title":"Experimental Evaluation of Fatigue Parameters Using Constant K Fracture Specimens","authors":"R. Cammino, M. Gosz, S. Mostovoy","doi":"10.1115/imece2001/pvp-25203","DOIUrl":"https://doi.org/10.1115/imece2001/pvp-25203","url":null,"abstract":"\u0000 We explore the use of constant K fracture specimens for experimental determination of fatigue properties of aluminum alloys. The shape of the contoured portions of the fracture specimens (required to keep the mode I stress intensity factor constant during crack propagation under constant cyclic loading) was obtained by a combined finite element-least squares minimization procedure. After conducting the experiments, the crack growth rate versus ΔK data was observed to exhibit significantly less scatter than fatigue data for the same material taken from the literature. In addition, the experimental procedure is much simpler to carry out than traditional closed-loop computer controlled procedures.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"232 1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121071293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/pvp-25209
A. Vermeulen, G. Heppler
The B-spline field approximation method is applied to the static deflection analysis of curved Euler-Bernoulli and Timoshenko beams. A formal definition of membrane locking is presented along with a simple test that allows a priori determination of a models susceptibility to membrane locking. Formulations for both types of beam models, that under certain discretizations experience membrane locking, are presented and additional formulations that can never experience membrane locking are presented for both beam models. Examples that demonstrate the efficacy of the membrane locking test and illustrate the two means of avoiding membrane locking are presented.
{"title":"Analysis of Curved Beams by the B-Spline Field Approximation Method","authors":"A. Vermeulen, G. Heppler","doi":"10.1115/imece2001/pvp-25209","DOIUrl":"https://doi.org/10.1115/imece2001/pvp-25209","url":null,"abstract":"\u0000 The B-spline field approximation method is applied to the static deflection analysis of curved Euler-Bernoulli and Timoshenko beams. A formal definition of membrane locking is presented along with a simple test that allows a priori determination of a models susceptibility to membrane locking. Formulations for both types of beam models, that under certain discretizations experience membrane locking, are presented and additional formulations that can never experience membrane locking are presented for both beam models. Examples that demonstrate the efficacy of the membrane locking test and illustrate the two means of avoiding membrane locking are presented.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130791712","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-11-11DOI: 10.1115/imece2001/pvp-25214
S. Khanna, R. Winter, P. Ranganathan, S. B. Yedla, K. Paruchuri
Glass fiber reinforced plastic composites are widely used as structural materials. These two phase materials can be tailored to suit a large variety of applications. A better understanding of the properties of the fiber-matrix ‘interphase’ can enable more optimum design of composites. The interphase is a microscopic region around the fiber and hence nano-scale investigation using nano-indentation techniques is appropriate to determine mechanical property variations. In this study the atomic force microscope with the Hysitron indenter has been used to determine the variation of the elastic modulus across the interphase for different silane coated glass fiber reinforced polyester composites. A comparative study of the elastic modulus variation in the interphase is reported. The results are discussed in the light of the current limitations of the instrumentation and analysis.
{"title":"Investigation of Nanomechanical Properties of the Interphase in a Fiber Reinforced Plastic Composite","authors":"S. Khanna, R. Winter, P. Ranganathan, S. B. Yedla, K. Paruchuri","doi":"10.1115/imece2001/pvp-25214","DOIUrl":"https://doi.org/10.1115/imece2001/pvp-25214","url":null,"abstract":"\u0000 Glass fiber reinforced plastic composites are widely used as structural materials. These two phase materials can be tailored to suit a large variety of applications. A better understanding of the properties of the fiber-matrix ‘interphase’ can enable more optimum design of composites. The interphase is a microscopic region around the fiber and hence nano-scale investigation using nano-indentation techniques is appropriate to determine mechanical property variations. In this study the atomic force microscope with the Hysitron indenter has been used to determine the variation of the elastic modulus across the interphase for different silane coated glass fiber reinforced polyester composites. A comparative study of the elastic modulus variation in the interphase is reported. The results are discussed in the light of the current limitations of the instrumentation and analysis.","PeriodicalId":270413,"journal":{"name":"Recent Advances in Solids and Structures","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2001-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134501021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：