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Aerospace Engineering

Aerospace Engineering

1989

Articles 1 - 3 of 3

Full-Text Articles in Engineering

Bodner-Partom Viscoplastic Constitutive Model And The Non Linear Finite Element Analysis Of A Stress Concentration At High Temperature, Faysal A. Kolkailah, A. J. Mcphate Oct 1989

Bodner-Partom Viscoplastic Constitutive Model And The Non Linear Finite Element Analysis Of A Stress Concentration At High Temperature, Faysal A. Kolkailah, A. J. Mcphate

Aerospace Engineering

The design and analysis of structural components to operate at elevated temperature and severe stress levels, such as a low-cycle fatigue-limited jet engine disk, require an accurate prediction of the nonlinear stress-strain . response encountered during the cyclic loading conditions. Nonlinear analysis of such components is normally carried out by a finite element code making use of constitutive theories in which the material response is separated into the two important groups of phenomena known as rate dependent "creep" and rate independent "plasticity." A number of viscoplastic. constitutive theories in which "creep" and ''plasticity" effects are combined _into a unified plastic …


Numerical Simulation Of F-18 Fuselage Forebody Flows At High Angles Of Attack, Lewis B. Schiff, Russell M. Cummings, Reese L. Sorenson, Yehia M. Rizk Mar 1989

Numerical Simulation Of F-18 Fuselage Forebody Flows At High Angles Of Attack, Lewis B. Schiff, Russell M. Cummings, Reese L. Sorenson, Yehia M. Rizk

Aerospace Engineering

As part of the NASA High Alpha Technology Program, fine-grid Navier-Stokes solutions have been obtained for flow over the fuselage forebody and wing leading edge extension of the F/A-18 High Alpha Research Vehicle at large incidence. The resulting flows are complex, and exhibit crossflow separation from the sides of the forebody and from the leading edge extension. A well-defined vortex pattern is observed in the leeward-side flow. Results obtained for laminar flow show good agreement with flow visualizations obtained in ground-based experiments. Further, turbulent flows computed at high-Reynolds-number flight-test conditions (M = 0.2, α = 30 °, and Re …


Numerical Representation Of Bodner Viscoplastic Constitutive Model, Faysal A. Kolkailah, Andrew J. Mcphate Feb 1989

Numerical Representation Of Bodner Viscoplastic Constitutive Model, Faysal A. Kolkailah, Andrew J. Mcphate

Aerospace Engineering

Nonlinear analyses of structural components are normally carried out by finite element codes making Use of constitutive theories in which the material response is separated into the two important groups of phenomena known as rate‐dependent “creep” and rate‐independent “plasticity.” A number of viscoplastic constitutive theories in which creep and plasticity effects are combined into a unified plastic strain model have recently been proposed and are still undergoing active development. In this paper, the constitutive equations of the Bodner‐Partom model are used to present the time dependent, inelastic properties of Inconel 718 at 650 °C. This representation covers a wide range …