Active bolster with heat-staked reinforcement

An active bolster for providing an interior trim surface of an automotive vehicle, comprising:

• a thermoplastic outer trim panel having a closed-loop bonding section on an inside surface, wherein the trim panel includes a first stud extending from the inside surface at the closed-loop bonding section and a second stud extending from the inside surface radially outward of the closed-loop bonding section;
• a thermoplastic expandable bladder member having a central attachment section configured to attach to a support structure of the vehicle, a welding flange along an peripheral edge, and a baffle section between the central attachment section and the welding flange, wherein the welding flange has a stud aperture receiving the first stud;
• a stepped bracket comprising a first plate overlying the welding flange and having a first aperture receiving the first stud, and comprising a second plate overlying the trim panel inside surface and having a second aperture receiving the second stud, wherein the studs have respective re-melted heads clamping the bracket in place;
• and
• an inflator for coupling an inflation gas into a space between the trim panel and bladder member to expand the bladder member in response to a crash event of the vehicle.