Light Truck Frame Joint Stiffness Study Phase 1 Final Report

JOINT STIFFNESS TOOLBOX
Notes:
* Modify the input values (yellow) based on
your design criteria. There are two columns in
which in to input and evaluate data, case 1 and
case 2. The calculated stiffness will be
displayed in red.
* Design variables are listed in order of
influence on stiffness.
Illustration Key:
A = Upper Crossmember
B = Outer Side Rail
C = Lower Crossmember
D = Inner Side Rail
Design Rules:
* These are the major contributors to
the joint stiffness:
- Crossmember thickness
- Crossmember end width
- Crossmember attached end width
* These are the minor contributors to
the joint stiffness:
- Inner side rail thickness
- Outer side rail thickness
- Upper crossmember thickness
- Flange width
- Side rail width
- Side rail height
* Click on the animation to the left of the
variables and loading conditions to see an
animation of respective shape variable or
loading condition.
* The password to unprotect cells in this
spreadsheet is: steel.
Joint Observations:
* The mass calculation is based on 150 mm
extension of joint members from the side rail to
interface. This is to serve as a reference, not
the absolute value.
* Flanges on top of the side rail deflect quite a
bit (local deflection).
* Lot of local deflection in the crossmember as
it bends upward near the rail…Tying the
crossmember together more would increase
the stiffness.
Vertical Loadcase (Mx)
* There is significant deflection in the inside
rail wall where the crossmember connects to
the side rail.
* Slight Deflection in the top side rail.
* Stiffness would increase if the crossmember
was welded together more in the area near the
side rail.
Torsional Loadcase (My)
* Flanges aredeflecting in both crossmembers
where they attach to the side rail.
* The stiffness would increase if the
crossmembers were welded more at the joint.
Figure 39: Joint 4 Joint Stiffness Toolbox Spreadsheet
Joint Observations, Notes and Design Rules
Report: A/SP-005-1 Light Truck Frame Joint Stiffness Study 66