Multi-material joint assembly, joint and method for a vehicle

A method of joining panel flanges of varying materials in a vehicle, comprising:

• positioning a washer on a blind side of a first panel and in engagement with the blind side to position a washer aperture defined by the washer in registry with a first panel throughole defined in the first panel;
• after positioning the washer on the blind side, inserting a rivet nut sleeve of a rivet nut through the first panel throughole defined in the first panel and through the washer aperture of the washer to position a flange of the rivet nut against a non-blind side of the first panel;
• deforming the rivet nut sleeve to create a bulged portion along the rivet nut sleeve for securing the rivet nut to the first panel;
• positioning a second panel on the non-blind side of the first panel to position a second panel throughole in registry with an axial throughole of the rivet nut;
• positioning a third panel on the non-blind side of the first panel to position a third panel throughole in registry with the axial throughole of the rivet nut;
• and
• inserting a bolt through the second and third panel throughholes and threadedly connecting the bolt to internal threads extending radially from the rivet nut sleeve into the axial throughole of the rivet nut to thereby secure the second and third panels to the first panel.

A multi-panel joint assembly for a vehicle, comprising:

• a first panel forming an outer skin on the vehicle;
• a second panel having a second panel flange portion overlapping the first panel;
• a third panel having a third panel flange portion overlapping the second panel flange portion;
• throughholes in registry with one another defined respectively in the first panel, the second panel flange portion and the third panel flange portion;
• a rivet nut received through the throughole of the first panel;
• a fastener received through the throughholes of the second and third panels and threadedly secured to the rivet nut for securing the second and third panels to the first panel;
• and
• a flat non-expanding washer interposed between the first panel and a deformed portion of the rivet nut for protecting the first panel from being damaged by the deformed portion.