A Study of the Correspondence Rule in a Viscoelastic Stress Analysis

Abstract

This thesis is mainly concerned with two fields of investigation;
the viscoelastic behaviour of plastics, and the numerical solution of
engineering problems by means of finite element methods.

The basic equations describing linear elastic behaviour are
modified to give corresponding equations for linear viscoelastic
materials, and various theoretical models are used to describe
viscoelastic behaviour.

The stiffness matrix for a tapered element of a beam is derived
for cases where the shear stress is neglected and where its effect is
allowed for, and S melebee solutions are obtained for various bending
problems. Bending is also considered as a plane stress problem, using
triangular elements.

By combining the results obtained from linear viscoelastic theory
and finite element methods theoretical solutions are obtained for a
number of more difficult viscoelastic problems, and the results are
compared with those obtained by experiment. Theoretical and experimental
results are also given for certain non-linear viscoelastic problems.

Finally methods of designing in plastics are discussed in
relation to the results previously obtained.

Throughout, extensive use is made of computer solutions, and the
development of the programs is detailed in the Appendix

Date of Award	1973
Original language	English