Method for producing a hollow composite members

A process for producing hollow composite members subjected, during operation, to dynamic bending and torsional loads and having an increased stiffness vis-a-vis bending and torsional loads, said process comprising the steps of:

• providing an outer material layer formed of a material having a predetermined tensile strength and a predetermined yield point;
• providing a tubular supporting member formed of a material having a tensile strength and a yield point lower than the predetermined tensile strength and the predetermined yield point of the outer layer within the outer layer;
• providing a stable wall surrounding said outer material layer;
• thereafter, simultaneously initially expanding the supporting member at opposite ends thereof into contact with corresponding opposite ends of said outer layer, thereby elastically expanding said opposite ends of said outer layer and producing a force-locking connection between the outer layer and the supporting member thereat;
• and
• subsequently expanding the supporting member in a region thereof extending between the initially expanded opposite ends into press-fit engagement with the outer layer with the outer layer resting against said stable wall thereby axially shortening the supporting member and thus generating at the opposite ends of the supporting member, a tensile presstress in the outer layer in a circumferential direction thereof and a compressive presstress in the outer layer in a longitudinal direction thereof.