Energy absorbing structures and method of providing such structures

An energy absorbing load bearing structure for a front or a rear portion of a frame of a vehicle body and to be oriented to extend in a direction toward an expected impact, said structure comprising:

• a unitary and one-piece longitudinally extending extruded member having a substantially uniform cross section resulting from extrusion of aluminum or aluminum alloy;
• said member having an end zone to be directed in the direction of the expected impact;
• said member having a length portion extending along the entire length of said member except for said end zone;
• said length portion having a material strength resulting from an aging heat treatment thereof;
• and
• said end zone having a material strength, resulting from an overaging heat treatment thereof, sufficiently lower than said material strength of said length portion such that said end zone is capable of axial compression deformation by a force acting on said end zone upon an impact being imparted to the portion of the vehicle body.