Perimeter Shear Test Quiz and Flashcards for Chassis Structure

Study Notes

Perimeter Shear Tests

Perimeter shear tests must be conducted to measure the force required to push or pull a 25 mm diameter flat punch through a flat laminate sample.
The sample must be at least 100 mm × 100 mm with identical core and skin thicknesses to those used in the actual chassis structure.
The sample must be manufactured using the same materials and processes as the actual chassis structure.

Test Fixture

The test fixture must support the entire sample, except for a 32 mm hole aligned co-axially with the punch.
The sample must not be clamped to the fixture.

Structural Documentation

All teams must submit a Structural Equivalency Spreadsheet (SES).
The SES spreadsheet form can be downloaded from the competition website.
Vehicles must be fabricated in accordance with the materials and processes described in the SES.
Teams must bring a copy of the approved SES to technical inspection.

Roll Hoops

Both roll hoops must be securely integrated to the primary structure using node-to-node triangulation or equivalent joining methods.
The minimum radius of any bend, measured at the tube centerline, must be at least three times the tube outside diameter.
Bends must be smooth and continuous with no evidence of crimping or wall failure.
The minimum area moment of inertia must be maintained in all areas, including the bends of the manufactured tubes.

Laminate Testing

Representative test panels must be built for parts of the primary structure or tractive system accumulator container.
The test panels must measure exactly 275 mm × 500 mm and have the same design, laminate, and fabrication method as used for the respective part of the primary structure.
The sides of the test panel must not be laminated (core material must be visible).
A 3-point bending test must be performed on the panel.
Data from the tests and pictures of the test samples and test setup must be included in the SES.
Pictures must show the distance between the two supports, dimensions of the load applicator, and test sample marking.

Wheels

Wheel mounting systems that use a single retaining nut must incorporate a device to prevent loosening of the nut and the wheel.
Wheel lug bolts and studs must be made of steel or titanium and show good engineering practice with adequate strength by calculations.
Wheel lug bolts, drive pegs, and studs must not be hollow.
Aluminum wheel nuts may be used if they are hard anodized and in pristine condition.

Tires

Vehicles must have two types of tires: dry tires and wet tires.
Dry tires are defined as the tires on the vehicle when it is presented for technical inspection.
Wet tires may be any size or type of treaded or grooved tire provided they meet specific requirements.
Tires on the same axle must have the same manufacturer, size, and compound.
Tire warmers are not allowed.
Special agents that increase traction may not be added to the tires or track surface.
A team can choose to use a single set of tires designed for both “dry” and “wet” conditions.

Description

This quiz covers the guidelines and requirements for conducting perimeter shear tests on chassis structures, including sample preparation and test fixture specifications. It's essential for engineers and technicians involved in material testing and structural analysis. Understand the importance of material selection and processing in chassis design.