Intro & Body Structure (Lectures (1-4) Flashcards
What is Automobile Safety?
Minimisation of the harmful effects caused by automotive accidents, particularly relating to human heath and life.
What is Active Safety?
Avoiding the accident, e.g. a braking system. Active safety systems usually require some form of driver input.
What is Passive Safety?
Protecting occupants involved in an accident, e.g. seat belt, airbag, body structure.
What are the driving forces for increased vehicle safety?
- Government legislation
- Competition
- Customer and public demand
- Availability of technology
- Product liability
- Automotive press
State vehicle structure types
- Space frame
- Monocoque (Unibody/Unitary)
- Body on frame
- Tub
1) What is a subframe?
2) What is a subframes purpose?
1) A structural component that carries certain components e.g. engine, drivertrain, suspension. Usually applied to monocoque or unitary vehicles. Subframes are usually welded together.
2) Isolate noise, vibration and harshness (NVH) from the rest of the body). Also has production benefits.
What is a spaceframe structure?
Internal frame covered with non-load bearing skin.
What is a monocoque or unibody structure?
Supports loads using external skin. Unibody is related to monocoque, where the body is integrated with the chassis into a single unit.
What is a chassis frame structure?
Seperate body to a rigid frame. The original method of body structure, also referred to as body on frame.
Pros and cons of a space frame structure:
Pros: Easy development, low tooling investment, good for low volume e.g. sports cars. Lightweight, crash energy absorption is high.
Cons: Assembly difficult to automate, high manufacturing labour costs, inefficient package space.
Pros and cons of unibody/monocoque structure:
Pros: Best NVH and stiffness per mass, good crash structure, range of materials possible, assembly can be highly automated.
Cons: Complex to design, large, expensive stamping presses and tooling required, low repairability.
Pros and cons of body on frame:
Pros: Easy devlopment, adaptable platform, durable, easy to repair.
Cons: Difficult to predict crash performance due to possible bending, chassis frame has low torsion resistance which compromises cornering, handling and grip.
How many key hard points are there on vehicle design?Name a few.
Any of:
- Sil and floor height
- Front wheel and tyre
- Chin height
- Front bumper location
- Leading Edge
- Hood profile
- Cowl/windshield touchdown
- Windshield opening and header
- Front roof
- Rear roof
- Rear header
- Rear cargo
- Rear bumper location
- Body rear lower
- Rear spindle
- Roof rail section
- Side glass
- Beltline location
- Body side profile
- Wheel coverage
