This paper determines the transient-stress distribution, due to imposed strain rates, which exists in bars made of a linear nonhomogeneous viscoelastic (Maxwell) material. The cases of constant and exponentially decreasing strain-rate histories are solved. The particular nonhomogeneity is an exponential variation of the fluidity in the thickness coordinate. I t is shown that this fluidity variation can be the result of a steady linear temperature gradient. One-dimensional strength of materials assumptions are made for the problems of axial extension and bending. I t is further assumed that all of the initial stresses due to heating have vanished prior to load application. I t is found in the case of constant strain rate that the stress distribution approaches the configuration associated with a purely viscous material after one relaxation time of the cold face. In addition, an approximate solution to the problem of constant load is given in Appendix A.
{"title":"Transient Stresses in Nonhomogeneous Viscoelastic (Maxwell) Materials","authors":"O. Dillon","doi":"10.2514/8.9409","DOIUrl":"https://doi.org/10.2514/8.9409","url":null,"abstract":"This paper determines the transient-stress distribution, due to imposed strain rates, which exists in bars made of a linear nonhomogeneous viscoelastic (Maxwell) material. The cases of constant and exponentially decreasing strain-rate histories are solved. The particular nonhomogeneity is an exponential variation of the fluidity in the thickness coordinate. I t is shown that this fluidity variation can be the result of a steady linear temperature gradient. One-dimensional strength of materials assumptions are made for the problems of axial extension and bending. I t is further assumed that all of the initial stresses due to heating have vanished prior to load application. I t is found in the case of constant strain rate that the stress distribution approaches the configuration associated with a purely viscous material after one relaxation time of the cold face. In addition, an approximate solution to the problem of constant load is given in Appendix A.","PeriodicalId":336301,"journal":{"name":"Journal of the Aerospace Sciences","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128112011","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}
approximation hand computation utilizing normal-shock equations and graphical thermodynamic-state data. The accuracy of the method is dependent on the assumed curvature between data points in plotting the tabular data of Gilmore and the error in logarithmic interpolation between curves. I t was estimated that these errors are between 1 and 10 per cent, with the error of the major portion of the data less than 5 per cent. The charts, in general, are not as accurate as could be obtained with an electronic computer, but the method is justified on the basis of the relatively low cost in time and effort. The charts should, nonetheless, prove useful to those working in hypervelocity gasdynamics until more refined calculations are available. The series of gasdynamic charts of reference 1 include the following properties: flow velocity, density, pressure, temperature, internal energy and enthalpy associated with a traveling normal shock, stationary normal shock (bow wave), stagnation point, and reflected normal shock. Curves are plotted versus incident-shock velocity for initial air densities of 10 1 to 10 ~ times atmospheric density and an initial temperature of 273.2°K. The range of incident-shock speeds is from Mach 10 to Mach 50 or to the limit of the thermodynamic data, 24,000°K. Included is a plot of Gilmore's data in the form of a Mollier diagram. The thermodynamic-state data were plotted as enthalpy versus density with lines of constant entropy and temperature because the curves become more orthogonal and, therefore, greater accuracy in reading is obtainable. This general plot is presented in Fig. 1. I t is felt that the gasdynamic charts are of general usefulness to many scientists and engineers and may satisfy a current need. However, the volume of the charts precludes publishing in a technical journal. The report is available to those interested and copies may be obtained by request to the author.
{"title":"A Note on the Impact Pressure Loading of a Rigid Plastic Spherical Shell","authors":"Rajkumar Sankaranarayanan","doi":"10.2514/8.8868","DOIUrl":"https://doi.org/10.2514/8.8868","url":null,"abstract":"approximation hand computation utilizing normal-shock equations and graphical thermodynamic-state data. The accuracy of the method is dependent on the assumed curvature between data points in plotting the tabular data of Gilmore and the error in logarithmic interpolation between curves. I t was estimated that these errors are between 1 and 10 per cent, with the error of the major portion of the data less than 5 per cent. The charts, in general, are not as accurate as could be obtained with an electronic computer, but the method is justified on the basis of the relatively low cost in time and effort. The charts should, nonetheless, prove useful to those working in hypervelocity gasdynamics until more refined calculations are available. The series of gasdynamic charts of reference 1 include the following properties: flow velocity, density, pressure, temperature, internal energy and enthalpy associated with a traveling normal shock, stationary normal shock (bow wave), stagnation point, and reflected normal shock. Curves are plotted versus incident-shock velocity for initial air densities of 10 1 to 10 ~ times atmospheric density and an initial temperature of 273.2°K. The range of incident-shock speeds is from Mach 10 to Mach 50 or to the limit of the thermodynamic data, 24,000°K. Included is a plot of Gilmore's data in the form of a Mollier diagram. The thermodynamic-state data were plotted as enthalpy versus density with lines of constant entropy and temperature because the curves become more orthogonal and, therefore, greater accuracy in reading is obtainable. This general plot is presented in Fig. 1. I t is felt that the gasdynamic charts are of general usefulness to many scientists and engineers and may satisfy a current need. However, the volume of the charts precludes publishing in a technical journal. The report is available to those interested and copies may be obtained by request to the author.","PeriodicalId":336301,"journal":{"name":"Journal of the Aerospace Sciences","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123701099","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":"Boundary-Layer Stabilization by Distributed Damping","authors":"M. Kramer","doi":"10.2514/8.8380","DOIUrl":"https://doi.org/10.2514/8.8380","url":null,"abstract":"","PeriodicalId":336301,"journal":{"name":"Journal of the Aerospace Sciences","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130332569","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 the Optimum Design of an I-Section Beam","authors":"S. Krishnan","doi":"10.2514/8.8210","DOIUrl":"https://doi.org/10.2514/8.8210","url":null,"abstract":"","PeriodicalId":336301,"journal":{"name":"Journal of the Aerospace Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130561135","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}
extend to infinity (where B = B^, the constant applied field), it follows that B = constant everywhere. In other words, for the particular case of (a) an infinite, straightsided, two-dimensional (x, y plane) wedge, (b) moving with constant vertical velocity (c) impacting on a semi-infinite incompressible perfect conductor (d) with applied magnetic field BA = BAk, where BA = constant, the magnetic field has no effect whatever upon the dynamic behavior of the wedge—that is, the pressure on and velocity of the wedge may be determined from the usual conservation equations of incompressible hydrodynamic theory, without regard for magnetic effects. From a similar analysis of the steady-state two-dimensional form of Eqs. ( l ) (3) , we may conclude the magnetic field B is constant along each streamline for these flows.
{"title":"An Axis System for Five and Six Degree of Freedom Airplane Dynamic Problems","authors":"William Wynn","doi":"10.2514/8.8596","DOIUrl":"https://doi.org/10.2514/8.8596","url":null,"abstract":"extend to infinity (where B = B^, the constant applied field), it follows that B = constant everywhere. In other words, for the particular case of (a) an infinite, straightsided, two-dimensional (x, y plane) wedge, (b) moving with constant vertical velocity (c) impacting on a semi-infinite incompressible perfect conductor (d) with applied magnetic field BA = BAk, where BA = constant, the magnetic field has no effect whatever upon the dynamic behavior of the wedge—that is, the pressure on and velocity of the wedge may be determined from the usual conservation equations of incompressible hydrodynamic theory, without regard for magnetic effects. From a similar analysis of the steady-state two-dimensional form of Eqs. ( l ) (3) , we may conclude the magnetic field B is constant along each streamline for these flows.","PeriodicalId":336301,"journal":{"name":"Journal of the Aerospace Sciences","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122204364","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 Note on the Skin-Friction Coefficient for Compressible Couette Flow","authors":"R. Inman","doi":"10.2514/8.7985","DOIUrl":"https://doi.org/10.2514/8.7985","url":null,"abstract":"","PeriodicalId":336301,"journal":{"name":"Journal of the Aerospace Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129705673","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 the Feasibility of Using Aerodynamic Control on Vehicles Operating in Regions of Slip Flow and Free-Molecule Flow","authors":"R. Swaim","doi":"10.2514/8.8987","DOIUrl":"https://doi.org/10.2514/8.8987","url":null,"abstract":"","PeriodicalId":336301,"journal":{"name":"Journal of the Aerospace Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128886294","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 Means of Improving the Static Performance of Cruise-Designed Shrouded Propellers","authors":"Arthur E. Johnson","doi":"10.2514/8.7751","DOIUrl":"https://doi.org/10.2514/8.7751","url":null,"abstract":"","PeriodicalId":336301,"journal":{"name":"Journal of the Aerospace Sciences","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131003711","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}
This paper assumes a requirement for an unmanned multiunit satellite to be assembled in orbit. The requirement to be met is to bring the satellites together so tha t they do not collide but actually rendezvous. The equations of motion of the rendezvous satellite in a relative coordinate system are derived and used to compute a final injection velocity which would effect collision after a time r. The velocity is corrected periodically by a command guidance system and just before impact retrothrust is applied. A terminal infrared homing sj^stem is required to actually accomplish physical contact and joining of the satellites. The first satellite placed in orbit is the "control satellite" and controls all the satellites to be assembled and contains the ccmputer, command guidance equipment, precision orientation equipment, and other features necessary to effect rendezvous. The succeeding satellites contain a propulsion system, a rough at t i tude control system, and a command receiver plus whatever scientific equipment they carry to perform their basic mission. This paper presents the following:
{"title":"Terminal Guidance System for Satellite Rendezvous","authors":"W. H. Clohessy","doi":"10.2514/8.8704","DOIUrl":"https://doi.org/10.2514/8.8704","url":null,"abstract":"This paper assumes a requirement for an unmanned multiunit satellite to be assembled in orbit. The requirement to be met is to bring the satellites together so tha t they do not collide but actually rendezvous. The equations of motion of the rendezvous satellite in a relative coordinate system are derived and used to compute a final injection velocity which would effect collision after a time r. The velocity is corrected periodically by a command guidance system and just before impact retrothrust is applied. A terminal infrared homing sj^stem is required to actually accomplish physical contact and joining of the satellites. The first satellite placed in orbit is the \"control satellite\" and controls all the satellites to be assembled and contains the ccmputer, command guidance equipment, precision orientation equipment, and other features necessary to effect rendezvous. The succeeding satellites contain a propulsion system, a rough at t i tude control system, and a command receiver plus whatever scientific equipment they carry to perform their basic mission. This paper presents the following:","PeriodicalId":336301,"journal":{"name":"Journal of the Aerospace Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122792284","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":"Comment on Nonlinear Pressure Method for Unsteady Aerodynamic Forces","authors":"H. Runyan","doi":"10.2514/8.8143","DOIUrl":"https://doi.org/10.2514/8.8143","url":null,"abstract":"","PeriodicalId":336301,"journal":{"name":"Journal of the Aerospace Sciences","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127961382","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}
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