Analytical-Experimental Approach to Verified Cohesive Zone Fracture Models in Engineering Applications

Proposal: CMS-9820912

PI: S. Saigal

Carnegie Mellon University

Title: Analytical-Experimental Approach to Verified Cohesive Zone

Fracture Models in Engineering Applications

Abstract: The chipping of coatings is studied using the cohesive

zonebased cohesive finite elements formulation. An integrated

analytical/experimental/numerical approach is followed. The cohesive

zone models are postulated to include irreversibility, rate-dependence,

and the effect of environmental factors. These postulations are both

guided by and validated by a set of experiments designed to highlight

various phenomenon occurring in the fracture of materials systems. The

developments are applied to the industrial application of chipping of

paint systems. For this application, multiple, interacting cracks

propagating along unknown trajectories need to be accounted for. The

cohesive finite elements approach provides a natural vehicle for such

cracks. Additional applications of cohesive elements include layered

constructions found in numerous engineering applications such as

composites, laminated sheets, coated metal, and microelectronic

devices. The proposed research is carried out in close cooperation with

the DuPont Company. The experiments for validation as well as for the

industrial application are carried out at DuPont. The cohesive models

are developed under the guidance of DuPont researchers to ensure that

these elements have full industry validity. The project serves as a

unique training mechanism for graduate students, introducing them to

university-industry interactions as well as to the effectiveness of

combined analytical/numerical/experimental approaches in solving

real-world problems.