Analytical evaluation of pull-out tests—The inverse problem

A numerical solution routine is proposed, which provides a simple and straightforward analytical method to evaluate the prevailing bond characteristics of a composite by means of a bond stress versus slip relation τ(s) using experimental data from pull-out tests. Time consuming and sometimes nonconvergent optimization procedures which have been used so far to determine τ(s) can be avoided. The proposed solution routine is applied and validated using experimental data from pull-out tests which were carried out at steel fiber/concrete systems. It is also shown that the underlying bond stress versus slip relation τ(s) is a material parameter, since it is not dependent on geometric factors of fiber and matrix, for example fiber diameter and embedded length.