AF4.5 Shoulder Harness Attachment

AF4.5.1 Load Applied: 13.2 kN at seat belt attachment angle per attachment point.

AF4.5.2 Application point: Both harness attachment points simultaneously

AF4.5.3 Boundary Condition: Fixed displacement (x,y,z) but not rotation of the bottom nodes of both sides of the front and main roll hoops.

AF4.5.4 Max Allowable Deflection: 25mm

AF4.5.5 Failure must not occur anywhere in structure

AF4.6 Lap & Anti-Submarine AF Harness Attachment

AF4.6.1 Load Applied: The loads specified in the monocoque harness attachment rules should be used on each att AF achment point.

AF4.6.2 Application point: All harness attachment points simultaneously (same load case)

AF4.6.3 Boundary Condition: Fixed displacement (x,y,z) but not rotation of the bottom nodes of both sides of the front and main roll hoops.

AF4.6.4 Max Allowable Deflection: 25mm

AF4.6.5 Failure must not occur anywhere in structure

AF4.7 Front Bulkhead & Bulkhead Support Off Axis

AF4.7.1 Load Applied: Fx = 149 kN, Fy= 17.25 kN, Fz 0 kN.

AF4.7.2 Application point: Create load application node in the front bulkhead plane at the center of the front bulkhead. Load application node may be rigidly connected to the front bulkhead and impact attenuator attachment points.

AF4.7.3 Boundary Condition: Fixed displacement (x,y,z) but not rotation of the bottom nodes of both sides of the main roll hoop and both locations where the main hoop and shoulder harness tube connect. Monocoques should use both sides of the bottom of the main hoop and both sides of the upper attachment point between the main hoop and monocoque.

AF4.7.4 Max Allowable Deflection: 25mm

AF4.7.5 Failure must not occur anywhere in structure

ARTICLE 5: GENERAL ANALYSIS REQUIREMENTS

The following requirements apply to the submitted structural certification process.

AF5.1 Good analysis practice must be used and all assumptions and modeling approximations are subject to approval during the SRC process. This includes but is not limited to mechanical properties, mesh size and mesh quality.

AF5.2 A Nastran analysis deck must be submitted electronically with the SRCF and supporting documentation. Nastran does not have to be used for the analysis, but is the required format for the organizer's to review the analysis input decks.

AF5.3 Tubes with wall thickness less than 1.25 mm (0.049 inches) cannot be included in the analysis

AF5.4 Holes in tubes may be neglected from the overall frame/monocoque model global results. However for each load case, the force and moments at both sides of the tubes need to be applied to a shell or

solid model of the tube with the hole or cutout geometry modeled. The tube around the holes and cutouts may not show failure.

AF5.5 Offsets between tubes at nodes need a detailed analysis similar to 5.3 where the actual connection is modeled using the end constraints from the overall vehicle model. Shell or solid models must be used.

AF5.6 The following alternative boundary condition is acceptable for all structural requirements. The alternative is to not include the nodal constraints and instead run the model with inertia relief. In this case the mass distribution of the vehicle must closely approximate the actual intended mass distribution. Evidence must be provided supporting the mass distribution used in the model. A driver mass of 77 kg and a minimum vehicle mass of 300 kg must be used, even if these differ from the team's predicted vehicle mass.

ARTICLE 6: INTRUSION PREVENTION

Since the exact configuration of the tubes is not specified this rule is intended to limit the size of

object which can intrude into the driver’s cell.

AF6.1 An impactor is defined as a circular disk with diameter of 254 mm (10 inches). The thickness is not relevant, but will generally be arounbd 2mm (0.080 inches) for the inspection process.

AF6.2 The primary structure between the front bulkhead and main roll hoop must not allow the impactor to enter the primary structure.

AF6.3 Anywhere on the structure where the impactor is attempted to be passed through the impactor must contact the structure in at least three points. This is not a projection requirement but a full 3- dimensional requirement.

AF6.4 The impactor is a 3- dimensional requirement. It applies to all faces of the structure, including the front, sides, top, floor and rear, excluding only the cockpit opening specified in T4.1.1. If the driver is seated fully in front of the main hoop then the requirement does not apply behind the main hoop. If

the driver is seated partially or fully behind the main hoop then the requirement extends to the end of the main hoop braces.

ARTICLE 7: NON-APPLICABLE RULES

The following rules are not applicable when building a frame to this alternative rule set.

AF7.1 T3.11.4 In the side view of the vehicle, the portion of the Main Roll Hoop that lies above its attachment point to the Major Structure of the Frame must be within ten degrees (10°) of the vertical.

AF7.2 T3.12.6 In side view, no part of the Front Hoop can be inclined at more than twenty degrees (20°)

from the vertical.

AF7.3 T3.13.3 In the side view of the Frame, the Main Hoop and the Main Hoop braces must not lie on the same side of the vertical line through the top of the Main Hoop, i.e. if the Main Hoop leans forward, the braces must be forward of the Main Hoop, and if the Main Hoop leans rearward, the braces must be rearward of the Main Hoop.

AF7.4 T3.13.4 The Main Hoop braces must be attached as near as possible to the top of the Main Hoop but not more than 160 mm (6.3 in) below the top-most surface of the Main Hoop. The included angle formed by the Main Hoop and the Main Hoop braces must be at least thirty degrees (30°). See Figure

3.

AF7.5 T3.13.6 The attachment of the Main Hoop braces must be capable of transmitting all loads from the Main Hoop into the Major Structure of the Frame without failing. From the lower end of the braces there must be a properly triangulated structure back to the lowest part of the Main Hoop and the node at which the upper side impact tube meets the Main Hoop. This structure must meet the minimum requirements for Main Hoop Bracing Supports (see Rule B.3.3) or an SES approved alternative. Bracing loads must not be fed solely into the engine, transmission or differential, or through suspension components.

AF7.6 T3.14.4 The Front Hoop braces must be attached as near as possible to the top of the Front Hoop but not more than 50.8 mm (2 in) below the top-most surface of the Front Hoop. See Figure 3.

AF7.7 T3.14.5 If the Front Hoop leans rearwards by more than ten degrees (10°) from the vertical, it must be supported by additional bracing to the rear. This bracing must be constructed of material per Rule B.3.3.1.

AF7.8 T3.20.1 The Front Bulkhead must be securely integrated into the Frame.

AF7.9 T3.20.2 The Front Bulkhead must be supported back to the Front Roll Hoop by a minimum of three (3) Frame Members on each side of the vehicle with one at the top (within 50.8 mm (2 inches) of its top-most surface), one (1) at the bottom, and one (1) as a diagonal brace to provide triangulation.

AF7.10 T3.20.3The triangulation must be node-to-node, with triangles being formed by the Front Bulkhead, the diagonal and one of the other two required Front Bulkhead Support Frame Members.

AF7.11 T3.25.4 With proper gusseting and/or triangulation, it is permissible to fabricate the Side Impact

Structural members from more than one piece of tubing.

Дата добавления: 2015-07-10