Industry Standards for Passenger Transit, Rail Vehicle Specifications

Composite Panels


Honeycomb

Honeycomb panels are typically used in ceiling and partition panels, and sometimes used in floor panels. Honeycomb panels offer strong, stiff, lightweight panels suitable for a variety of applications, however, concentrated loads on these panels can deform the skin and damage the honeycomb core, significantly weakening the panel.

In addition to the standards listed below, it is important to specify that edge treatments and fastening points be suitable reinforced to prevent crushing of the core material. Typical edge treatments may include aluminum extrusions, formed metal "U" channels, filled epoxy edges, formed skin edges, etc. Typical fastening points may include metal reinforcing blocks, tapping blocks, glued in threaded inserts, epoxy filled sections, etc. It is also important to consider the skin thickness in the area where it will be used. Panels exposed to areas where they could be damaged by concentrated loads, such as swinging luggage, or carts, should have a suitable skin thickness to prevent dents and core damage.

Standard: MIL-HDBK-349 - Manufacture And Inspection Of Adhesive Bonded, Aluminum Honeycomb Sandwich Assemblies For Aircraft
Purpose: This handbook provides information on the manufacture and inspection of adhesive bonded, aluminum honeycomb sandwich assemblies for aircraft. It was developed specifically to be used as a reference guide that provides information useful in meeting specification requirements for individual parts.
Criteria: Specify compliance with standard
Usage: Shall comply with applicable requirements of MIL-HDBK-349
Standard: MIL-C-7438 - Core Material, Aluminum, For Sandwich Construction
Purpose: This standard provides specifications for aluminum honeycomb material.
Criteria: Specify compliance with standard
Usage: Shall comply with applicable requirements of MIL-C-7438
Standard: MIL-A-9067 - Adhesive Bonding Process And Inspection Requirements For
Purpose: This standard provides specifications for bonding of various assemblies including composite honeycomb panels
Criteria: Specify compliance with standard
Usage: Shall comply with applicable requirements of MIL-A-9067