METAL AND COMPOSITE BONDED JOINTS

Metal and Composite Bonded Joints

Title: Metal and Composite Bonded Joints

Authors: Anyfantis, K.

Year of Publications: 2003

Finite element predictions of composite-to-metal bonded joints with ductile adhesive materials.Composite Structures,

Volume: 94, Issue 8, pp. 2632-2639

SUMMARY

This research article that is reviewed in this assignment is the work that aims to provides finite element predictions of adhesive joints that involve dissimilar materials and a ductile adhesive layer. A recently developed mixed-mode law is utilized by the author for the description of the elastoplastic loading and fracture response of the adhesive layer under Mode I and Mode II conditions. This model is implemented in interface elements that are used to replace conventional continuum elements for modeling the adhesive area. The potential of the proposed model for analysis and design purposes is shown through simulations of experimentally tested CFRP-to-steel adhesive joints taken from the literature. Additionally, a numerical parametric study is conducted on an effort to investigate the effect of the overlap length and the thickness of the adherents to the strength of the joints.

Critical Analysis

There are several techniques available for the repair of defected materials where some type of discontinuity is present or their stiffness or strength have been partially lost. A typical repairing practice involves the utilization of supplemental structural materials on and in the vicinity of the defect. The corresponding structural design of this paper aims at compensating the loss of strength or stiffness owed to the corresponding defect. This paper examine the problem of the reliable cooperation of the materials involved, i.e. the repairing and the parent structural elements. Among the methods that are widely used for bringing together two similar or dissimilar structural materials, adhesive bonding has attracted the interest of many researchers and design engineers because of the distinct properties it offers. One of the major reasons or needs for the development of the adhesive bonding technology is that joining of dissimilar materials is permitted and thus these can be used in a complex structure or assembly, creating so-called “hybrid structures” (i.e., structures that, as a result of being composed of more than one material, offer properties, performance, or other attributes not attainable in any individual material). Dissimilar materials often enable the attainment of high structural efficiency in several ways.

The main scope of this paper is to present the potential of the new model for the structural analysis and design of adhesively bonded joints with dissimilar adherents. For this purpose, this work provides finite element predictions, of experimentally tested CFRP-to-steel adhesive joints from the literature. Initially, the numerical predictions with the EPZ model are compared with the experimental results and with predictions obtained with the DZT. In the following, the developed EPZ tractions are provided as these evolve during the loading of the joints. Additionally, a numerical parametric study is conducted on an effort to investigate the effect of the overlap length and the thickness of the adherents to the strength of the joints.

The author in this paper examined the experimental work ...