Frames and Chassis Flashcards
The _________ frame is the backbone of all heavy duty trucks.
chassis
A truck frame is a dynamic component. It is designed to_________when subjected to vehicle loading and road forces
flex
What defines the type of operation that the truck is suited to?
The extent to which a truck frame can flex
The ________ supports the cab, hood, and powertrain components, along with the body and payload.
frame
The two main components of a ladder-type frame are the two longitudinal members, which are generally referred to as ________
rails.
___________ is measured for comparative purposes by resist bend moment (RBM).
Ultimate frame strength
RBM is factored by section modulus and __________ strength.
yield
Section modulus (SM) concerns the shape of frame beams. High SM produces a more _____________. Low SM produces higher flexibility.
rigid frame
Hardened steel frame rails are formed from high-strength alloy steel, quenched and tempered (heat-treated) to a minimum yield strength of __________ psi.
110,000 psi.
Low SM frames provide greater flexibility and, therefore, more ______________
ride forgiveness.
High SM provides the kind of rigidity and twist resistance required by a ____________
dump truck application.
Most frames are available with either inside or partial inside __________reinforcements or outside reinforcements.
channel
______________ are used to increase rigidity (SM) and provide a greater RBM than can be obtained by using a single mainframe rail.
Reinforcements
__________________ are designed to connect the frame rails.
Cross-members
Cross-members provide rigidity and strength, along with __________ to withstand twisting and bending stresses encountered when operating on uneven terrain.
sufficient flexibility
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.
the flanges
The most common frame rail used on heavy- duty trucks is the ___________design. Multiple frame rails can increase SM and RBM.
C-channel
A bent frame can decrease the control a driver has over a vehicle during an emergency and increase the _____________
chances of an accident occurring.
Frame damage can be generally categorized as diamond, ______, sideway, sag, and ____.
twist, bow
Frame reinforcement can be channel, fishplate, or L-sectioned, but they should be of the same ________________________
grade and thickness of steel as that of the frame.
