No abstract

Approved REPO T D CUMETATON P GE0MSNo. 0704-0188 bic ,eagw" anh amaa ftvCiOMti~~ i.,fweIa. lliM.1e to .oy..q. I hourM Wf rtW01te. including the11M ION ICWIA9 wig "theIon. 10811W49 evatifg 46L& WVICOL "ta14 N W wIe visato neede. NoW CORIWIfin and0 Icewinn" t%o coflhoe Of iformation. Send C.0moniat Idoaher tis burdenm etionaW of en, o0~wi aet o the couo Do int9 mo. .nddnq swep"iim for f,~ow"q tis biordis. to W.,Dwn ftes neEeuafw $9-kAUL awY~orso for ItImtOan O00rtom .1 a40onL I a I$ Jistgfl8. ABSTRACT "Temperature changes that take place ahead of a crack tip in the plastic zone have been analyzed using dislocation modeling of the plastic zone. The development of the process zone and that of the plastic zcne is described in terms of dislocation generation and their movement at high strain rates of deformation. Among the various terms contributing to the total energy, the energy dissipation terms have been identified. In particular, the plastic work dissipation rate has been calculated using the phonon viscous drag forces acting on the dislocations. In our analysis, the transition from the heavily deformed process zone to the less heavily deformed p, Ic zone is gradual and continuous. 1.AEC UEOL