Frames and Chassis

Question 1

The _________ frame is the backbone of all heavy duty trucks.

Answer 1

chassis

Question 2

A truck frame is a dynamic component. It is designed to_________when subjected to vehicle loading and road forces

Answer 2

flex

Question 3

What defines the type of operation that the truck is suited to?

Answer 3

The extent to which a truck frame can flex

Question 4

The ________ supports the cab, hood, and powertrain components, along with the body and payload.

Answer 4

frame

Question 5

The two main components of a ladder-type frame are the two longitudinal members, which are generally referred to as ________

Answer 5

rails.

Question 6

___________ is measured for comparative purposes by resist bend moment (RBM).

Answer 6

Ultimate frame strength

Question 7

RBM is factored by section modulus and __________ strength.

Answer 7

yield

Question 8

Section modulus (SM) concerns the shape of frame beams. High SM produces a more _____________. Low SM produces higher flexibility.

Answer 8

rigid frame

Question 9

Hardened steel frame rails are formed from high-strength alloy steel, quenched and tempered (heat-treated) to a minimum yield strength of __________ psi.

Answer 9

110,000 psi.

Question 10

Low SM frames provide greater flexibility and, therefore, more ______________

Answer 10

ride forgiveness.

Question 11

High SM provides the kind of rigidity and twist resistance required by a ____________

Answer 11

dump truck application.

Question 12

Most frames are available with either inside or partial inside __________reinforcements or outside reinforcements.

Answer 12

channel

Question 13

______________ are used to increase rigidity (SM) and provide a greater RBM than can be obtained by using a single mainframe rail.

Answer 13

Reinforcements

Question 14

__________________ are designed to connect the frame rails.

Answer 14

Cross-members

Question 15

Cross-members provide rigidity and strength, along with __________ to withstand twisting and bending stresses encountered when operating on uneven terrain.

Answer 15

sufficient flexibility

Question 16

Attachments to the frame rails should be made to the frame rail web and never to ____________ because stresses are highest in the flange areas that are subjected to tensional and compressional loads.

Answer 16

the flanges

Question 17

The most common frame rail used on heavy- duty trucks is the ___________design. Multiple frame rails can increase SM and RBM.

Answer 17

C-channel

Question 18

A bent frame can decrease the control a driver has over a vehicle during an emergency and increase the _____________

Answer 18

chances of an accident occurring.

Question 19

Frame damage can be generally categorized as diamond, ______, sideway, sag, and ____.

Answer 19

twist, bow

Question 20

Frame reinforcement can be channel, fishplate, or L-sectioned, but they should be of the same ________________________

Answer 20

grade and thickness of steel as that of the frame.