scope:

Introduction

In addition to the compound strength of a bond determined through destructive testing, the qualitative and quantitative description of the failure pattern provides valuable information with regard to the effectiveness of the bond. This guideline gives concrete expression to the existing EN ISO 10365 standard on the evaluation of failure patterns for bonds in car body construction and describes the most important failure patterns, as can occur in the destructive testing of car body bonds, including repair bonding, as well as the quantification process with regard to the occurrence of different failure modes on a failure surface (multiple failures).

An overview table has been created for simple classification of failure modes. In addition to the failure modes listed in the standard, the failure types "WF - white failure" and "COR - corrosion" have been included. A white failure can occur e.g. in the case of metals as joining parts in conjunction with high-strength, hot-curing epoxy-resin adhesives. In the case of multiple failures, i. e. the occurrence of several failure modes on a destructively tested test specimen, the use of a grid for determining the proportional surface area percentage of the individual failure modes described. A catalogue of clearly evaluated failure patterns is provided in the appendix of the document.

Here, we wish to point out that evaluation of the failure pattern is exclusively visual and that detailed failure mechanisms are not considered. This guideline is intended as an aid for objective and reproducible failure pattern evaluation.