Evolution of Hardening and Damage during Viscoplastic Deformation.
Abstract
Although theories of nonlocal mechanics were developed to address the role of hardening and damage microstructures in heterogeneous engineering materials, these theories frequently require additional, but unavailable, information concerning the concentrations or size distributions of the microstructures to compute the internal stresses. An objective of this work was to develop generalized equations for the size distributions of hardening and damage microstructures as functions of the stress, strain rate, and the scale of observation, and thus to reduce the above information requirements. The two approaches employed addressed incompressible and compressible materials. Limitations identified from the incompressible formulation were employed to construct a variational integral for compressible materials. Definition of the variables in this integral was completed except for a strain rate scale factor. The associated Euler Lagrange equations are expected to provide the desired microstructure evolution equations. Keywords: Hardening, Damage, Viscoplasticity, Nonlocal stress polarization, Variational methods, Scale factors, Fractals.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 15, 1987
- Accession Number
- ADA190714
Entities
People
- R. E. Williford