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Goal: Determine the best mounting solution between the steel tube members of a chassis and the proposed structural bottom panel of the chassis.
Factors to consider
- The fastening method must not protrude through the aerobody
- Fastening system should be elegant
- Off the shelf solutions are preferable because they are cheaper, save time and are more reliable
In order to accomodate for potential manufacturing defects int he bottom panel, should we use hard mounting points at specific areas of the chassis, or should we assume that a long interface will exist where the tubes can lie flat on the composite panel?
Comparisons between fastening methods
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Removability
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A solution comprising of clickbond threaded bushings, welded sheet metal plates and mechanical fasteners is displayed below. The solution was inspired by the Stanford Solar car team's design. There are many advantages to this solution.
- It's an off the shelf solution used for many applications in many industries, likely by lots of people.
- It will provide an elegant, lightweight solution in a clean form factor
- It comes with jigging tools making it relatively easy and straightforward to install
- It uses mechanical fasteners, which is a physical link between the two components. This will give the team more peace of mind as opposed to relying purely on the shear strength of epoxy and hoping for the best.
- It is cost effective
- It is predesigned, so integrating this solution will not take as much time
- Because the solution mounts at specific hard points, we can adjust it and add some room/ tolerancing to make sure that the components will fit should there be manufacturing defects
We will have to perform some materials tests before using it.
Here is a description from the click bond website:
Click Bond adhesive-bonded bushings enable construction using lightweight structures manufactured from composite sandwich structures with crush-sensitive or low strength core materials such as honeycomb or foam. They provide localized reinforcement and strongpoints for threaded attachment.
The accompanying disposable installation fixtures offer rapid, consistent installation as well as continuous clamping of the joint during cure, ensuring a strong bond. Internal elastic fixtures are available with select bushings for reduced footprint applications.
Non Permanent Mounting Solutions
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