Method of anchoring a connector, and connector

A method of anchoring in a connector a lightweight building element, the lightweight building element including a first building layer and a second building layer arranged at a distance from the first building layer, the method comprising the steps of:

• providing a connector that comprises a sleeve element and a piston element, the piston element comprising a shaft portion and being movable in an axial direction relative to the sleeve element, while the sleeve element at least partially surrounds the shaft portion, wherein at least one of the sleeve element and of the piston element comprises a thermoplastic material;
• providing a through hole in the first building layer, the through hole comprising a circumferential wall;
• inserting the connector until a distal portion thereof rests against the second building layer;
• coupling mechanical oscillations into the piston element while pressing the piston element towards the distal side, and thereby liquefying at least a portion of the thermoplastic material at an interface portion between the sleeve element and the piston element while the interface portion is adjacent the circumferential wall or distal with respect to it, thereby generating a liquefied thermoplastic material portion, and causing liquefied thermoplastic material of the liquefied thermoplastic material portion to flow radially outward and into structures of the first building layer and/or along an interior surface of the first building layer;
• and
• letting the liquefied thermoplastic material portion re-solidify to form a positive-fit connection with the first building layer.