1. New Vehicle Construction
Introduction
Vehicle Body Structure
Bumper reinforcements
Front Rails
Engine Cradles
A, B, C and D Posts
Roof Rails
This is the structure of the unibody. It is designed to transfer collision forces around the passenger compartment to protect the vehicle occupants.

2. Vehicle Body Structure
One-piece hydroformed body side rings.
Door hinges secured by thick through-bolts located in A- and B-pillars.
Cast magnesium transverse beam behind the instrument panel.
Discuss vehicle structure and process changes by working your way around the schematic
Triple-rolled A-post design resists roof collapse.
Shock towers connected solidly to instrument panel.
Lateral tie bars that connect the front longitudinal rails were closed to stiffen the front structure and improve crashworthiness.
Hydroformed engine cradle ( not shown )

3. Enhanced Bumper Bumper Reinforcement
The front bumper reinforcement connects both front lower rails. The purpose of the bumper reinforcement is to direct all energy in a frontal collision to the frame rails so that they can collapse and direct the collision energy around the passenger compartment.
Bumper Reinforcement

4. Crumple Zones
This is the desired effect after the crash. The crumple zones absorb the force of the impact while the body rings maintain an intact passenger compartment.
( Courtesy Of Audi )

5. Beam with Crumple Zones
COLLAPSE ZONES
Collapse zones are built into the front section to absorb collision energy.
This is achieved through the use of indentations and by drilling holes into the structural parts to allow them to collapse.
These collapse zones reduce the amount of force that reaches the passenger compartment.
A good comparison is being hit with a pillow, which collapses and absorbs energy versus being hit with a pipe which does not absorb any energy.

6. Crumple Zone Design
The front section is also designed to direct the collision energy down a pre-determined path to the center section and around the passenger compartment.

7. (HSLA) Beam with Crumple Zones
This 2000 Volvo has upper and lower front rails with crumple zones.
Note the crumple zone outlined in the red square to the rear of the headlight.
The side impact beam is knee-braced off of the lower B-pillar post and connected in line with the HSLA beam in the front cowling.

8. Front Rail Construction
The front lower rails support the engine and front suspension. They also absorb collision energy and direct the energy to the rocker panels and away from the vehicle occupants.
Lower Rail

9. Front Rail Construction
The upper rails support the fenders and the hood and are designed to absorb collision energy and transmit that energy to the A-Posts.
Upper Rail

10. Enhanced Strut Tower Strut Tower
The strut towers along with the Apron Assemblies connect the upper and lower rails and position the front suspension for proper alignment.

11. Hydroformed Engine Cradle
The engine and transmission are designed to drop out of the bottom of the engine compartment. This helps prevents intrusion into the passenger compartment.

12. Engine Cradle Drops
The front end of the vehicle continues to collapse and absorb energy as the engine cradle continues to move back and down.

13. A – Post Construction A-post
The A-Post supports the front door hinges and helps to form the center section of the vehicle which is designed not to collapse in a collision.
This center section is designed to protect the passengers and stay intact in all types of collisions.
A-post

14. A – Post Construction Windshield Post
The Windshield Post supports the windshield and is designed to prevent the roof from collapsing in a rollover collision.
The windshield post is also part of the vehicle center section.
Windshield Post

15. A – Post Construction Hydroformed
The A-Pillar on this Volvo C-70 is hydroformed from ultra-high strength steel.

16. B – Post Construction B-Post
The B-Post on a vehicle with a roof help to support the roof and contain the front door Nader Pin and rear door hinges. The B-Post is part of the vehicle center section.
NOTE: Door designs are changing. The B-Post may contain the front and rear door Nader Pins, or no hinges or Nader pins at all.
B-Post

17. Can your cutter cut this B-Post
How many layers of steel do you see in this B-Post?

18. A & B Post Reinforcements
Vehicle makers may use multiple layers of steel for reinforcement or round bars like the Subaru Forrester.

19. Construction and Materials
The C-Post helps to support the roof makes up part of the vehicle center section. On a 2-door vehicle the C-Post also supports the rear glass.
C-Post

20. Construction and Materials
The D-Post is the post rearward of the C-Post. It is found on Station Wagons, Vans and SUVs. It support the roof and makes up a part of the rear hatch or door opening.
D-Post

21. Construction and Materials
The roof reinforcement provides structural support for the roof. It also connects all of the posts on the sides of the vehicle. It is designed to prevent the roof from collapsing in a rollover and to direct collision energy around the passenger compartment in front and rear impacts.
Roof Reinforcement

22. Roof System Construction
ULTRA HIGH - STRENGTH STEEL
To ensure that the roof can support the weight of the vehicle Extra High-Strength Steel is used for the construction of the roof reinforcements.