Quality Assessment of Adhesive Bond Based on Dielectric Properties
Composite materials are widely used in Aerospace, Marine and Automotive structures to reduce weight and increase performance. Adhesive bonding improves the stress distribution between the composite materials / dissimilar materials and ensures a lighter structure than conventional fastener joints. But still there is not much research on the Non-Destructive strength estimation and life prediction, or the damage prognosis of the adhesive bond. One of the main problems when using adhesive bonding is a “kissing bond” which is a weak adhesion bond alternatively called zero volume disbond. Typically, convectional non-destructive methods cannot detect this kissing bond.Broadband Dielectric Spectroscopy, BbDS, is a well-known and established tool for dielectric material characterization which has been used in polymer industries for a long time, e.g., in composite manufacturing this method is used to monitor the curing process. Dielectric spectra of the heterogeneous materials alter with changes in the materials system, i.e., with changes in morphological heterogeneity, electrical and structural interactions between particles, and shape and orientation of the constituent phases of the material system. During the service life of an adhesive bond, degradation occurs on many levels which can lead to the final failure of the adhesive bond. The process of microdefect interaction and accumulation to create a final fracture path is an active research area. This paper presents an experimental investigation based on measuring dielectric properties of an adhesively bonded joint to show how the relationship between the strength of an adhesively bonded structure is uniquely linked with changes in the bulk dielectric response that reflect the internal defect state of the material system, including the weakness of an adhesion bond.
Authors: Muthu Ram Prabhu Elenchezhian, Vamsee Vadlamudi, Priyanshu Kumar Banerjee, Chaitanya Dave, Anik Mahmood, Rassel Raihan, and Kenneth Reifsnider
Conference: SAMPE Seattle 2017