PDR Vehicle Panel Metallurgy & Body Structure 3

Question 1

Which vehicle body area is most likely to use hot-stamped boron steel (HSBS), and why does this matter for PDR?

Accepted Answer

A-pillars, B-pillars, and rocker panels, because these are crash-critical structural members that cannot safely be PDR-repaired

Answer

Hood and trunk lids, because they need lightweight panels

Answer

Door skins, because they require extra corrosion resistance

Answer

Roof panels, because they must support the weight of the vehicle in a rollover

Question 2

The 'yield strength' of a metal panel is important for PDR technicians because it represents:

Accepted Answer

The stress level at which the metal transitions from elastic to permanent (plastic) deformation

Answer

The maximum temperature the panel can withstand before melting

Answer

The amount of force needed to remove a factory dent

Answer

The hardness rating used to select the correct PDR rod tip

Question 3

A PDR technician is working a door skin and notices the metal feels increasingly stiff and resistant with each rod pass, even though the dent is not fully repaired. The most likely cause is:

Accepted Answer

Cumulative work hardening has reduced the metal's ductility with each deformation cycle

Answer

The rod tip is too large for the dent size

Answer

The door skin has a hidden reinforcement brace

Answer

The ambient temperature dropped, causing the metal to contract

Question 4

In multi-material vehicle construction, where aluminum and steel panels are joined on the same vehicle, a PDR technician must primarily be aware of:

Accepted Answer

Galvanic corrosion risk at the joint and different tool pressure requirements for each material

Answer

The difference in magnetic properties, which affects rod positioning

Answer

The need to use different lighting systems for each material type

Answer

Aluminum panels being always located on the driver's side only

Question 5

Which panel characteristic is described by the term 'memory' in PDR, and how does it vary by material?

Accepted Answer

The metal's tendency to return toward its original undamaged shape when worked — stronger in steel than aluminum

Answer

The panel's factory color code stored in the VIN data

Answer

The technician's ability to recall the original panel shape from memory

Answer

The stored energy in a compressed spring reinforcement behind the panel

Question 6

Hydroforming technology in modern vehicle body panels creates:

Accepted Answer

Complex, high-strength panel shapes formed by fluid pressure, resulting in thinner walls with better structural geometry

Answer

Panels made by injecting water into the metal to create texture

Answer

A waterproof coating applied to inner panel surfaces

Answer

Panels that can self-repair small dents when exposed to water

Question 7

When a crease dent occurs on a panel, why is it considered more difficult to repair than a round dent of equivalent diameter?

Accepted Answer

A crease involves metal that has been forced past its yield point along a line, creating a stressed fold with work-hardened edges that resist reshaping

Answer

Crease dents always require painting, making PDR impossible

Answer

Round dents always occur in thicker panel areas

Answer

Crease dents typically damage the inner panel structure automatically