Paper number 596

RESIDUAL STRESSES AND THERMOPLASTIC ADHESIVE ENVIRONMENTAL CRACKING

Wenping Zhao and Karthik Ramani1

1Composites and Polymer Processing Laboratory (CPPL)
School of Mechanical Engineering
Purdue University, West Lafayette, IN 47907-1288, USA

Summary The work presented here is concerned with thermoplastic-bonded joint durability. Residual stresses in the thermoplastic adhesive layer are generated in thermal bonding process. In application, joints will face various environmental attacks both at the adhesive itself and at joint interfaces. In this study, transparent glass/polycarbonate/glass sandwich samples were used. Adhesive cracking was observed during environmental soaking of the sandwich samples. Furthermore, the adhesive cracking phenomena occurred only when the glass adherend was roughened before bonding. Smooth glass adherend did not cause the adhesive cracking. A finite element model revealed the effects of local adherend surface feature on the residual stress state in the adhesive layer. Residual stresses in the adhesive layer were demonstrated as a primary reason for the cracking.
Keywords residual stress, durability, adhesion, crack, surface topography.

Theme : Durability and Ageing

[ HOME ]  [ BACK ]