Twelve-cornered strengthening member, assemblies including a twelve-cornered strengthening member, and methods of manufacturing and joining the same

A motor vehicle assembly, comprising:

• a strengthening member having a twelve-cornered cross section along a length of the strengthening member from a first end of the strengthening member to a second end of the strengthening member;
• and
• an automotive component having a twelve-cornered cross section at an end of the automotive component connected to the second end of the strengthening member;
• wherein the cross section of the automotive component transitions from the twelve-cornered cross section to a four-cornered cross section along a longitudinal axis of the automotive component.

A method of manufacturing a motor vehicle assembly, the method comprising:

• providing a strengthening member having a twelve-cornered cross section in at least a portion of the strengthening member;
• providing an automotive component forming a structural portion of the assembly, the automotive component having a four-cornered cross section along at least a portion of a length of the automotive component;
• providing a transition between twelve corners and four corners at an end of at least one of the strengthening member and the automotive component where the strengthening member and the automotive component are connected to one another;
• and
• connecting the strengthening member to the automotive component.