THEORETICAL-ANALYSIS OF STRAIN RESPONSE ENVELOPES USING INCREMENTALLYNONLINEAR CONSTITUTIVE-EQUATIONS

This paper reviews some incrementally non-linear constitutive equation s of interpolation type, and proposes a new approach to illustrate the discrepancies between different interpolation models. This approach u ses the strain response envelopes, based on experimental data when res tricted to triaxial plane, and the Jacobian of the constitutive equati ons to examine the loss of uniqueness. A new family of interpolation f unctions is proposed to meet the three requirements: C-1-continuity of strain response envelope, correct description of experimental data, a nd respect of the one-to-one property. (C) 1998 by John Wiley & Sons, Ltd.