Nondestructive Evaluation (NDE) of Coated Multi-layered Fiber Reinforced Polymer (FRP) Components

Navy SBIR 21.1 - Topic N211-071
NAVSEA - Naval Sea Systems Command
Opens: January 14, 2021 - Closes: February 24, 2021 March 4, 2021 (12:00pm est)

N211-071 TITLE: Nondestructive Evaluation (NDE) of Coated Multi-layered Fiber Reinforced Polymer (FRP) Components

RT&L FOCUS AREA(S): General Warfighting Requirements

TECHNOLOGY AREA(S): Ground / Sea Vehicles

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with section 3.5 of the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop a method to detect defects in thick-coated Fiber Reinforced Polymer (FRP) and hybrid/integrated laminate construction.

DESCRIPTION: Thick coated Fiber Reinforced Polymer (FRP) laminate and hybrid/integrated laminate composites are used in critical component applications which demand that the component be free of defects of defined dimension and location. These defects include porosity, voids, delamination, moisture intrusion and defects in bond-line integrity. The configurations include FRP laminate (e.g., E-glass/vinyl ester, E-glass/epoxy, carbon/epoxy), FRP hybrid laminates, FRP/viscoelastic polymer, FRP/foam, and FRP/wood. The defects have the potential to interfere with acoustic performance and structural integrity and generally degrade ship performance.

Shipyards are often required to remove coatings to permit inspection or remove components all together to permit inspection from both sides. Both of these scenarios are time-consuming and negatively affect the sustainment costs and maintenance schedule. An inspection method is needed that can identify defects in composite components through thick (>1/4") coatings and from a single surface, thus increasing efficiency of inspections and decreasing ship impact during maintenance periods.

Current nondestructive testing technologies (i.e., visual inspection [VT], ultrasonic testing [UT], eddy current testing [ET]) are limited in their ability to:

a) detect/quantify porosity in laminates/viscoelastic polymers

b) detect bond-line defects

c) detect water intrusion. The method to detect defects that the Navy seeks should be compatible with manufacturing, fabrication and in-service environments.

The method must be able to detect the range of identified defects and provide size and depth information, specifically, but not limited to:

a) Delaminations/voids in FRP:1/4" through 6" of material

b) Porosity in FRP/viscoelastic polymers: >1% in a cubic foot of material

c) Water intrusion: >5% by weight per cubic foot of laminate or FRP/core material

d) Bond-line defects: 1/4" through 3" of material.

The method must be non-invasive (as opposed to destructive sampling), should demonstrate inspection time efficiency, and provide clear presentation of anomalies in the material, specifically in the selected regions of the material(s), such as a bond-line. Detection of disbonds in the FRP/coating bond-line is a highly desired outcome and an in-service inspection need. Detection of moisture in cored FRP sandwich construction is another desirable feature. These components are often accessible from one surface only, particularly for in-service inspection and covered with thick coatings. A nondestructive testing method applicable to these requirements is not commercially available.

Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. Owned and Operated with no Foreign Influence as defined by DOD 5220.22-M, National Industrial Security Program Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence Security Agency (DCSA). The selected contractor and/or subcontractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances, in order to perform on advanced phases of this contract as set forth by DCSA and NAVSEA in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material IAW DoD 5220.22-M during the advance phases of this contract.

PHASE I: Define, develop, and demonstrate an inspection capability to detect and characterize the identified defects in representative sample material including porosity, voids, delamination, defects in bond-line integrity and moisture intrusion. Actual inspection capability shall be demonstrated (supported by analysis and/or simulation) for a variety of sample materials including coated and uncoated FRP laminate and FRP hybrid laminate composites. The Phase I Option, if exercised, will include documentation of performance demonstration and conceptual specification of a practical nondestructive testing system to be developed in Phase II.

PHASE II: Develop, demonstrate, and qualify a robust nondestructive evaluation system for detection and characterization of the specified defects in coated and uncoated FRP laminates, FRP hybrid laminates, FRP/viscoelastic polymer, FRP sandwich construction including foam and wood cored construction. These defects include porosity, voids, delamination, defects in bond-line integrity and moisture intrusion. The detection capability must be quantifiable through demonstrations with representative samples. . Note: NAVSEA will define the defect characteristics; and specify equipment characteristics appropriate for use during fabrication, installation, and in-service inspection. Representative equipment will be demonstrated.

Work with NAVSEA to determine representative standards for each of the targeted defects. NAVSEA will provide samples incorporating various defects for laboratory validation by the contractor.

It is probable that the work under this effort will be classified under Phase II (see Description section for details).

PHASE III DUAL USE APPLICATIONS: A portable, robust, efficient, and effective nondestructive inspection system for detection and characterization of defects in coated and uncoated FRP laminates, FRP hybrid laminates, FRP/viscoelastic polymer, FRP sandwich construction has a large potential commercial market. The capability validated in Phase II will translate directly into similar technical performance requirements in commercial market applications. As for Phase III transition, this work will benefit the following industrial applications:

a) Reinforced rubber products for volumetric inspection. Applications include expansion joints in power plants and chemical processing facilities.

b) Multi-layer armor, primarily for military applications (and some civilian law enforcement).

c) Multi-layer composites for wind turbine blade application.

d) Part quality of polymer composites for automotive and marine applications.

e) Ceramic matrix composites, primarily for aerospace applications, both military and civilian.

f) High density polyethylene (HDPE) joint inspections, specifically thermal butt fusion weld joining, for failure to properly fuse.

g) Fiber reinforced plastic (FRP) for absolute thickness and inter-layer disbond, specifically for FRP pipe and tank inspection in chemical processing, oil and gas as well as municipal infrastructure.

REFERENCES:

  1. Multiple contributing authors. "American Society of Nondestructive Testing Aerospace Industry Handbook. American Society of Nondestructive Testing, 2014. https://www.asnt.org/MajorSiteSections/Publications/NDT_Handbooks/Industry_Handbook_Aerospace.aspx
  2. Schmidt, Karl, Editor. "The MW Compendium: Articles on Microwaves (Draft)." American Society for Nondestructive Testing, 2016. https://asnt.org/-/media/Files/Misc/CP-105-2020-Draft_20190430.ashx?la=en&hash=6380B0A53B0E18CC31E57F3735C4FB61AE6411B8
  3. Schmidt, Karl, Technical Editor. "Field Service Microwave Inspection Experience in Dielectric Components, Materials Engineering." Materials Evaluation, American Society for Nondestructive Testing, 2016. https://ndtlibrary.asnt.org/2016/FieldServiceMicrowaveInspectionExperienceinDielectricComponents

KEYWORDS: Nondestructive testing; bond-line integrity; bond-line imaging; composite integrity; composite volume imaging; Fiber Reinforced Polymer laminate; FRP

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