Accession Number : ADP000007

Title :   Energy Density Thresholds Associated with a Moving Heat Source,


Personal Author(s) : Sih,George C. ; Chang,C. I.

Report Date : SEP 1982

Pagination or Media Count : 14

Abstract : High concentrations of energy can affect the local material properties and cause irreversible material damage in the form of excessive deformation and/or fracture. Considered in this communication is a traveling heat source along a line such that transient thermal stresses are created. Depending on the intensity and speed of the traveling heat source and material properties, material damage threshold is assessed by examining the stored energy causing the local elements to change shape as well as volume. To this end, the proportion of the energy density associated with distortion and dilatation is considered to be important. Their individual contribution is weighted automatically by taking the stationary values of the energy density function with respect to the polar angle that locates the direction of yielding and fracture. It is shown that for a sufficiently powerful heat source, it is possible to cause damage of the material by yielding and fracture with or without the addition of mechanical load. Results are reported for the 2024-T3 aluminum material and are useful for developing a methodology to quantitatively assessed material damage of systems subjected to high energy sources. (Author)

Descriptors :   *Aluminum alloys, *Structural properties, *Heat transfer, *Fracture(Mechanics), *Failure(Mechanics), Energy transfer, Thermal stresses, Thermal conductivity, Crack propagation, Modulus of elasticity, Density, Equations, Threshold effects, Numerical analysis

Subject Categories : Metallurgy and Metallography
      Numerical Mathematics

Distribution Statement : APPROVED FOR PUBLIC RELEASE