INCREMENTAL KINEMATICS FOR FINITE-ELEMENT APPLICATIONS

A kinematical algorithm is proposed in which the input is the incremen tal deformation gradient corresponding to an increment in motion for a time step, and the output is a constant rate-of-stretching tenser and a rotation tenser. The concept of algorithmic objectivity is discusse d, with a stronger statement of objectivity than those advanced in pre vious,works being set forth. The importance of strong objectivity is i llustrated for applications in which moderately large rotation increme nts are to be expected. Accuracy of the proposed algorithm is discusse d and illustrated with example calculations, and it is shown that the accuracy of the algorithm may be extended to arbitrary order. Also, th e computational effort associated with the proposed algorithm is seen to compare favourably to that of other algorithms.