F.7.8 Attachments

F.7.8.1  Each attachment point between the monocoque or composite panels and the other Primary Structure must be able to carry a minimum load of 30 kN in any direction.

   a. When a Roll Hoop attaches in three locations on each side, the attachments must be located at the bottom, top, and a location near the midpoint

    b. When a Roll Hoop attaches at only the bottom and a point between the top and the midpoint on each side, each of     the four attachments must show load strength of 45 kN in all directions

F.7.8.2 If a tube frame ( F.6, F.11.2 ) meets the monocoque at the Attachments, the connection must obey one of the two:

a. Parallel brackets attached to the two sides of the Main Hoop and the two sides of the Side Impact Structure

b. Two mostly perpendicular brackets attached to the Main Hoop and the side and back of the monocoque

F.7.8.3  The laminate, brackets, backing plates and inserts must have sufficient stiffness, shear area, bearing area, weld area and strength to carry the load specified in F.7.8.1 in any direction.

    Data obtained from the laminate perimeter shear strength test (F.4.3.5) must prove sufficient shear area is provided.

F.7.8.4 Proof that the brackets are sufficiently stiff must be documented in the SES.

F.7.8.5  Each attachment point requires no less than two 8 mm or 5/16” minimum diameter Critical
Fasteners, see T.8.2

F.7.8.6  Each attachment point requires backing plates which meet one of:
a. Steel with a minimum thickness of 2 mm
b. Alternate materials if Equivalency is approved

F.7.8.7  The Front Hoop Bracing, Main Hoop Bracing and Main Hoop Bracing Supports may use only one 10 mm or 3/8” minimum diameter Critical Fasteners, see T.8.2 as an alternative to F.7.8.5 above if the bolt is on the centerline of the bracing tube to prevent loading the bolt in bending, similar to the figure below. 

F.7.8.8 Each attachment point must contain one of the two:
a. A solid insert that is fully enclosed by both the inner and outer skin b. Local elimination of any gap between inner and outer skin, with or without repeating skin layups