Design, Fabrication and Testing of a Versatile Outfitting Attachment System Kit for Naval Sandwich Panels

Period of Performance: 07/02/2001 - 01/15/2002


Phase 1 STTR

Recipient Firm

Kazak Composites, Inc.
Woburn, MA 01801
Principal Investigator
Firm POC

Research Institution

University of Massachusetts Lowell
1 University Ave.
Lowell, MA 01854
Institution POC


KaZaK Composites and the University of Massachusetts-Lowell will conduct an analytical and experimental investigation of technology alternatives for mounting hardware to composite sandwich panels used in shipboard structures. The KCI/UML team will work with Bath Iron Works to ensure that attachment system solutions developed during the program are compatible with demanding and diverse needs associated with Naval fleet service. Phase I work will fall into five general categories: 1) Evaluation of available fastener systems and suppliers (the currently favored approach for meeting Navy RFP specifications is a full depth potted insert system), 2) Classical and finite element analysis of various combinations of insert and panel, including an evaluation of effects of likely installation errors, such as poor back surface attachment or misalignment, on strength of the installed attachment, 3) Fabrication of sandwich test panels made with various cores, faced with glass or carbon skins, including purposely less-than-perfect insert installations, as well as different manufacturing processes including a VARTM-like process and pultrusion, 4) Testing candidate systems statically for in-plane and out-of-plane failure loads, plus strength after shock loading and/or fatigue cycling, and 5) Definition of a generally-applicable, pre-kitted panel insert system and User's Manual for use by shipbuilders and maintenance personnel.KaZaK Composites is actively involved in the development of numerous products that make use of our unique capability to pultrude sandwich panel structures up to 10 feet wide, 2 feet thick and of unlimited length. Current KCI programs include use of these pultruded sandwich panels in large deployable military buildings, Navy pier structures (with skins as thick as 3 inches) and various transportation systems. We plan to use our own developmental hardware as the first "customer" for the kitted attachment system proposed for development here. Once proven by STTR and KCI's own internal applications, we expect to find a wide range of potential customers in infrastructure, transportation and construction applications that are making increasing use of composite sandwich panel technology. Attachment to sandwich panels is one of the major technology barriers to use of this lightweight construction configuration. A proven, documented and readily-available kit should be a popular convenience and easily-marketable product as the use of this type of structure becomes more widely accepted by industries with less technical sophistication that current aerospace, marine and transportation fabricators.