Recent Advances in Solids/Structures and Application of Metallic Materials最新文献

{"title":"Scientific Implications in High Peak Power Nd:YAG Laser Material Removal of Al-30%SiC Composite","authors":"K. Nagarathnam, X. Chen, J. Mazumder","doi":"10.1115/imece1997-0553","DOIUrl":"https://doi.org/10.1115/imece1997-0553","url":null,"abstract":"\u0000 This paper outlines the scientific implications of a high peak power, high beam quality Nd:YAG laser in manufacturing applications and discusses the significance of optimizing key laser process parameters in material removal characteristics of a Al-30% SiC composite. The potential applications of this emerging technology are primarily targeted towards advanced components fabrication in industries such as aeronautic, space, power generation, and automotive. Some of the unique advantages include better beam characteristics such as focusability, improved dimensional accuracy and tolerance, higher production rates, process maneuverability using suitable lens and fiber optic beam delivery systems, and elimination of mechanical tool wear in comparison to the traditional drilling techniques. Percussion drilling experiments were performed in two batches on 12.5 mm thick plates of Al-30% by volume of SiC composite material. The laser consists of a cw-pumped Nd:YAG oscillator followed by a cw face-pumped, total internal reflection Nd:YAG slab for the amplifier gain medium, a master-oscillator-power-amplifier (MOPA) configuration. Both the second harmonic wavelength (532 nm) and the fundamental wavelength (1064 nm) were used, with average powers ranging from 35 W to 90 W. Two pulse formats were employed: Q-switched or simultaneously modelocked and Q-switched. A concentric nozzle was used with O2 assist gas at 45 psig pressure at the regulator. The holes were produced both normal to and 45° angle to the surface. Based on the measured geometrical data, circularity and dross ratios have been proposed and correlated with the process variables. The absence of cracking was evident from the transverse cross-sections of the produced holes. Results of the microstructural aspects such as the morphology and concentration of alloying elements in the matrix and second phase constituents of the unaffected substrate and the nearby regions of the laser drilled holes provided encouraging evidence for the retention of similar morphology, minimal heat affected zone, and little or no recast layer, under select process conditions. The findings in this present study emphasize the uniqueness of this modern laser material removal technique as an advanced manufacturing tool with broader future potential.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131271278","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}

{"title":"Strength and Stability Analyses of Retaining Structure Models for the Fracturing Fluid Characterization Facility","authors":"A. Striz, Keyur Thakore","doi":"10.1115/imece1997-0528","DOIUrl":"https://doi.org/10.1115/imece1997-0528","url":null,"abstract":"\u0000 Millions of dollars are spent annually on hydraulic fracturing for oil and gas well stimulation. Various researchers have proposed models to optimize the stimulation treatment, with limited success due to a lack of understanding of the behavior of critical parameters in the models, especially the fracturing fluids. Thus, the Gas Research Institute and the U.S. Department of Energy are sponsoring a project at the University of Oklahoma to investigate fracturing fluids in a large physical fracture model, the Fracturing Fluid Characterization Facility (FFCF). This simulator was initially expected to consist of a parallel plate simulator as large as 16 ft high by 100 ft long, with an internal pressure as high as 1200 psi, to determine critical fluid parameters under full-scale operating conditions. A smaller and more economical version of the simulator (7 ft high by 9 1/3 ft long) has since been built and moved to its own facility. As the reaction forces of the originally intended structure were tremendous (over 275,000,000 lbf for a full-scale simulator), structural analyses were essential.\u0000 Thus, static strength and stability (buckling) analyses were performed on various full-scale models and on the smaller final version of the pressure retaining structure for the FFCF simulator. An interior segment of each structural model consisting of the pressure chamber and the reaction beam/ plate/tie rod assemblies was modeled in detail and analyzed by the finite element method using the industry standard code MSC/NASTRAN together with the MSC/XL pre- and postprocessor. In addition to the linear analyses for all models, a material nonlinear analysis was run for Model 1. General buckling analyses by the finite element method were performed on square plates and on retaining structure plates with various boundary conditions to determine the influence of these conditions on the critical buckling loads. Finally, the full final model was analyzed for buckling proving the stability of the design.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117037606","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}

{"title":"A Model for Predicting the Precipitation Strengthening Response of Precipitation Hardened Alloys Strengthened by Ordered Precipitates","authors":"J. Fragomeni, B. Hillberry","doi":"10.1115/imece1997-0527","DOIUrl":"https://doi.org/10.1115/imece1997-0527","url":null,"abstract":"\u0000 A model was developed for predicting the precipitation hardening response of a particle strengthened alloy determined from the microstructure, composition, and heat treatment. The precipitates in the microstructure which impede dislocation motion and control the precipitation strengthening response as a function of the aging practice were used as the basis for determining the strength depending on the actual size distribution of particles. The particle size and distribution were determined from the microstructure via the heat treatment and composition. Consequently a micromechanical model was determined for predicting the variation in yield strength with aging time, temperature, and composition. The overall micromechanical model which was determined from the particle coarsening kinetics, dislocation mechanics, thermodynamics, resolved shear strength, as well as the particle strengthening mechanisms based on the dislocation particle shearing and dislocation particle looping interaction mechanisms was used to predict the strength of the demonstration alloy based on the microstructure. The demonstration alloy selected as the vehicle to model the precipitation strengthening response was a particle strengthened aluminum-lithium-zirconium alloy. Using this demonstration alloy, the overall model predicted from the microstructure the variation in strength with aging time, aging temperature, and composition, in the underaged, peak-aged, and overaged heat-treatments. The predicted aging curves were in good agreement with the experimental results for different aging practices.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128459594","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}

{"title":"Numerical Simulation of Inertia Welding of Inconel 718","authors":"V. Balasubramanian, Y. Li, T. Stotler, J. Crompton, N. Katsube, W. Soboyejo","doi":"10.7449/1997/SUPERALLOYS_1997_719_719","DOIUrl":"https://doi.org/10.7449/1997/SUPERALLOYS_1997_719_719","url":null,"abstract":"\u0000 This paper presents the results of numerical simulations and experimental measurements of the temperature distributions in the heat affected zone. These were obtained for the inertia welding of IN718 to IN718 and the inertia welding of IN718 to 1045 Steel. Microstructures of the heat affected zone are presented along with microhardness profiles for the similar and dissimilar inertia welds. The measured temperature profiles are compared with numerical/finite element predictions of the temperature distributions in the heat affected zone. The effects of friction welding parameters on the temperature distributions in the heat affected zone are modeled using the finite element method. The experimental results are compared with predictions from numerical analysis. The implications of the results are then discussed in the final section of the paper.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1997-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127349870","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}

{"title":"Fracture Mechanics Approaches to the Prediction of Fatigue Life of a Beta Titanium Alloy (Ti-15V-3Cr-3Al-3Sn)","authors":"B. Rabeeh, Alfred. B. Soboyejo, S. Rokhlin, W. Soboyejo","doi":"10.1115/imece1996-0159","DOIUrl":"https://doi.org/10.1115/imece1996-0159","url":null,"abstract":"\u0000 This paper highlight the results of recent efforts to develop mechanistically based, fracture mechanics models, for the prediction of the total fatigue life in Ti-15V-3Cr-3Al-3Sn (Ti-15-3). Acoustic emission techniques and visual observation (light and scanning electron microscopy) methods are used to monitor fatigue initiation and propagation phenomena in Ti-15-3. Mechanistically-based fracture mechanics idealizations of initiation and propagation stages are then formulated for the prediction of fatigue life. Using the measured initial crack length as the key variable in fatigue life prediction equations, the bounds in the predicted initiation and propagation lives are estimated using fracture mechanics techniques. The paper highlights the advantages of simplified fracture mechanics methods in the prediction of fatigue life.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115004832","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}

{"title":"On Analysis of Discrete Systems With Variable Structure","authors":"D. Gavrilov, O. Vinogradov","doi":"10.1115/imece1996-0145","DOIUrl":"https://doi.org/10.1115/imece1996-0145","url":null,"abstract":"\u0000 In many applications a discrete system undergoes structural (or connectivity) changes when subjected to loads or deformations. Each time the connectivity between the discrete elements changes a new system of equations must be generated and solved. In the paper a new method based on the numerically generated inverse matrix for the entire system allows the updating of the latter after each change in connectivity instead of generation and recalculation of the new system of equations. The method is symmetrical with respect to addition and elimination of links. The presented algorithm is based on recursive relationships between the inverse matrices for two systems differing by one element. The method is demonstrated for plane granular clusters, i.e. systems of particles bound together and having zero internal degrees of freedom, which is equivalent to any overconstrained system comprising the two-node finite elements. The problems of numerical efficiency and accuracy of the method are discussed and demonstrated on numerical examples.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122427178","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}

{"title":"Studies of Artificial Cracks at Simulated Rocket Motor Liners by the Frozen Stress Method","authors":"C. Smith, E. F. Finlayson, C. Liu","doi":"10.1115/imece1996-0138","DOIUrl":"https://doi.org/10.1115/imece1996-0138","url":null,"abstract":"\u0000 Two types of bimaterial specimens, one consisting of two photoelastic materials with different critical temperatures (Type A) and one consisting of a photoelastic material with and without aluminum powder (the powder added to alter the modulus of elasticity without changing the critical temperature (Type B)) are constructed by bonding two halves of the dissimilar materials together. Each type of specimen contains an artificial edge crack along the bond line and loaded normal to the bond line. After evaluating the two specimen types by measuring the variation of the Mode I stress intensity distribution through the specimen thickness, Type B was selected as a superior model and its features studied in detail.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114520984","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}

{"title":"Finite Element Analysis of a Dissimilar Mixed Mode Bimaterial Interfacial Fracture Specimen","authors":"Jinmiao Zhang, G. Lu, V. Kenner, W. Soboyejo","doi":"10.1115/imece1996-0156","DOIUrl":"https://doi.org/10.1115/imece1996-0156","url":null,"abstract":"\u0000 A finite element model of a dissimilar mixed mode bimaterial interfacial was generated using the commercial FEMAP software and analyzed using ABAQUS. Finite element techniques were used to estimate the strain energy release rates of interfacial cracks in a copper/moulding compound system. The finite element results are shown to be in good agreement with theoretical predictions of the strain energy release rate obtained from an analytical linear elastic fracture mechanics model. The finite element techniques were also used to estimate the loading conditions that are required to avoid contact between the crack surfaces under monotonic loading.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116016827","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}

{"title":"Simulated Metallic Structures for Use in Radar Measurements","authors":"Jeffrey J. Barclay","doi":"10.1115/imece1996-0154","DOIUrl":"https://doi.org/10.1115/imece1996-0154","url":null,"abstract":"\u0000 The Naval Undersea Warfare Center, Division Newport has been active in quantifying radar signatures of periscopes, communication masts, and sensors, as well as different materials. Development of computational prediction codes, along with radar measurements of various targets, have provided the primary analysis tools in signature management. Because of the nature of these radar measurements, techniques were developed to simulate metallic structures. With these techniques, manufacturing time and cost were greatly reduced along with large reductions in structure weight. These techniques primarily used electrically conducting tape and paint as coatings to simulate a metallic, electrically conducting surface. Simulation validation, with computational code, was achieved with the production and measurement of several simulated metallic structures. By achieving this validation, reasonable geometrical design changes could be developed and studied with computational predictions. The most recent experiment involved using a simulated metallic surface to provide an entire environment for the targets under test. Again by using these metallic coated structures to create a multipath environment, expense and manufacturing time were reduced. This simulated environment will, it is hoped, provide a very controllable and repeatable measurement tool for incoherent scattering and fully polarimetric studies of a multipath environment.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125805979","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}

{"title":"Failure Mechanisms of a Ceramic-Metal Interface Under the Application of High Temperature Loading","authors":"J. Zarzour, E. J. Onesto","doi":"10.1115/imece1996-0146","DOIUrl":"https://doi.org/10.1115/imece1996-0146","url":null,"abstract":"\u0000 Controlled experiments with a thermal spray coating of aluminum oxide (alumina) on high purity nickel metal base were carried out to examine the mechanisms of cracking and delamination. Control of these phenomena will enhance the life of thermally sprayed components subjected to thermal shock. These experiments along with computer models will advance the fundamental understanding of this ceramic-metal interface. A plasma spray torch was used to prepare the test specimens, and a high power radiative furnace was used to apply a thermal shock load to the specimens during testing. Geometric effects studied include thickness ratio, thickness to diameter ratio, absolute coating thickness, and the effect of a peak temperature.\u0000 Experimental results show that using the same critical thermal cycle, specimens with 1mm thick coating failed by cracking, specimens with coating thickness below 1mm did not show any type of failures, and specimens with coating thickness higher than 1mm failed by spallation inside the coating layer.\u0000 A finite element model incorporating the rate-dependent inelastic behavior of nickel at high temperature was developed to provide a realistic estimate of the residual stresses that develop during the thermal cycle. From transient heating to room temperature cooling, residual stress gradient from compressive to tensile was observed in the coating layer. With decreased coating thickness, this phenomenon was less pronounced.","PeriodicalId":407468,"journal":{"name":"Recent Advances in Solids/Structures and Application of Metallic Materials","volume":"203 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124222017","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}