Bonded Joint Analysis Method

Award Information
Agency: Department of Defense
Branch: Navy
Contract: N68335-12-C-0377
Agency Tracking Number: N12A-004-0072
Amount: $79,954.00
Phase: Phase I
Program: STTR
Awards Year: 2012
Solitcitation Year: 2012
Solitcitation Topic Code: N12A-T004
Solitcitation Number: 2012.A
Small Business Information
NextGen Aeronautics
2780 Skypark Drive, Suite 400, Torrance, CA, -
Duns: 106823607
Hubzone Owned: N
Woman Owned: N
Socially and Economically Disadvantaged: Y
Principal Investigator
 Akhilesh Jha
 Principal Investigator
 (310) 995-4859
 ajha@nextgenaero.com
Business Contact
 Zoltan Feher
Title: Manager, Contracts and Pr
Phone: (310) 626-8384
Email: zfeher@nextgenaero.com
Research Institution
 University of California, Berkeley
 Patricia Gates
 2150 Shattuck Ave., Suite #31
Berkeley, CA, 94704-5940
 (510) 642-8109
 Nonprofit college or university
Abstract
Adhesive bonds are increasingly finding their applications in aerospace and automotive structures. The adhesive bonding gets rid of fasteners, thus reducing stress concentrations and damage initiation sites. In addition, elimination of fasteners results in significant weight savings. In order to use adhesive bonding with confidence and certify integrity of bonded structures, certain issues regarding the integrity of bonded joints need to be addressed. The key issues that need to be addressed are - strength prediction, durability, damage tolerance, and non-destructive inspection. The focus of this study is to quantitatively predict the strength of a general bonded joint under multi-axial loading. The main difficulty with modeling a bonded joint is how to consider a generalized mode of failure emanating from multi-axial loading. In this work, we advance the traditional cohesive zone finite element method by replacing empirical failure criteria of limited traction-displacement curves by stress-based generalized failure criteria obtained from first principle but validated through experiments. While this method does not eliminate the need to experiments, it does provide a comprehensive approach to model failure of bonded joints. Phase I study will also undertake coupon-level tests in order to both inform and validate the method

* information listed above is at the time of submission.

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